I think it is a lot better when a youtuber advertises sponsors himself within the video than watching the automated ads with their intrusiveness, their increased volume and their unrelated commercial
Hate to admit how long I've been a photographer, but your video did a good job of explaining f/stops. I think those who didn't cut their teeth on "old school" f/stops can appreciate the optical effects an aperture can produce (bokeh), and understand T-Stops if they equate the "T" to light Transmission, which accounts for the variance of brightness you mentioned. As for how it affects different sensor sizes, I'm pretty sure there is more to it than filters or lens coatings or pixel density since in today's cameras so much of the image quality is the result of what the image processing software built into the firmware does.
This video was news to me. I had never heard of T-Stops before prior to reading the title to this video. I was thinking that T-Stpps were derived to British tea time going into this video. Now I am probably going to check for the T-stops for the lenses I own to see where they each stand and see if I need better lenses. This may help when taking pictures in low light situations or want more light to capture things.
Interesting topic Tony, but you leave me wondering if this can be used to my advantage, like using the Sony STM for outdoor portraits. You can get the bokeh of f/2.8 while shooting at T/5.6 - like a built in ND filter.
This can never be an advantage because it is one way change. You can always add a Nd filter but you can never recover the detail lost due to stop lost.
Yes you can get the shallower depth of field without overexposing the image on sunny days. When there is less light of course you pay the price with more noise
It's technically impossible to have the F stop and T stop identical. The biggest reason for the difference is usually the amount of elements the light has to pass through. The quality of the elements, their configuration, coatings and other glass additives will also affect light transmission. As a general rule prime lenses tend to have closer f stop/ T stop ratings than zooms mainly because they have less elements given their simpler design. I do think however that all lenses should show both the F stop and T stop.
Thx Tony, simple explanation of F vs T-Stops! This topic has got a lot of press lately. Like you said "it's 150 year old technology that is not truly relevant in today's digital world! So it is very confusing for many especially since Photography crossed into the Video world. I think in the near future all manufactures with start listing both F & T-Stops on lenses, unless it is a specific Cine lens.
It would be worth mentioning that the 100mm STF lens has this deviation between f-stops and T-stops due to the apodization filter, which is intentional.
Wouldn't say the video was misleading, just an addition that could have been made to show that Sony didn't get all ethical with this lens and decided to come clean with the T-stop :-P A manufacturer can't really get away with not stating the T-stop for STF lenses anyway.
hmm but such a large difference, compared to Fujinon XF 56mm F1.2 R APD whihc also has apodization filter, but it has minor light loss.. 1.2 = 1.7 1.4=1.8 2=2.3 2.8=3 4=4.2 5.6=5.6. and the light loss only applies up to F4, after that it's the same.
I think the reason for the lack of a switch from f-stops to T-stops for photographers is basically due to marketing. Having the true transmittance of a lens made available to the public might put off people from buying them, especially since most of these lenses have such different f-stops and T-stops in a single lens. Putting both values - or just the T-stop - on photography lenses would make them even more expensive to manufacture and to buy, since the transmittance of the glass would have to be drastically improved, maintained and controlled.
Well, one reason why photographers might still use f-stops, is because when you had the old film days of shooting video, they NEEDED to know that the lenses performed the same in regards to the light pass-through (therefore using T-stops), but in photography, half a stop or even a quarter of a stop oflight is well spent, if you can have a wider aperture and therefore shallower depth of field... So it still makes sense for photographers to use the f/ value, because in our case (especially today), it has a bigger impact on the final result. Still, it would be great to know the T-stop of the lens, so manufacturers should include that in the product details ...
How are you doing your experimentation to figure some of these differences out, not only in this, but other videos as well? In this case did you look it up on dxomark or did you figure it out yourself? As a software developer I love the amount of science you bring to all of your videos and tutorials, but lately have been wondering how you figure this stuff out.
Buddy Lindsey great question, I have been wondering the same. I'd love to see a video where Tony and Chelsea show how they do the testing that they often mention in their videos.
I'm guessing that he got the T-stop of a lens in which he used in comparison to the other. He mentioned the Mitakon f0.95 lens against the Canon 50mm f1.4 (ADDED: He may have meant the 35mm F1.4, but my argument stays the same). The Canon F1.4 has a T-stop of 1.6. So if the Mitakon looks about the same in exposure to the Canon but just a smidge brighter... Well, you too could probably make an educated guess.
I'm no expert, but it seems to me that a higher t-stop number may not necessarily be a bad thing. Lens manufacturers use coatings on the lenses to improve properties like chromatic aberration, at the cost of absorbing some light. So even though you might be getting a slightly dimmer image, it may look better overall. Just a thought. I'm open to ideas.
Some people don't know the difference between f and t stops and blame their flash for overrating its GN. I always need to explain this concept to them.
Excellent video. Thanks!!! Does this explain why manufactureres advertise their cameras as having the ability to work at high ISO when in fact the results are disappointing and marred by high levels of grain?
Say f-stops if talking about DoF and t-stops if talking light sensitivity. I'd say there is a case for using both. Manufacturers ought to list both for their lenses. Oh and we should probably also mention that the Sony STM lens has such a high T-stop number because that's how STM lenses are. A better example of the same lens in both versions would probably be the Samyang 85mm F/1.4. It's just called the Samyang 85mm T/1.5 but is identical apart from the declicked T-stop ring and a cine-focus ring.
The Angenieux 28-340mm is actually an F 2.9 T 3.4. I agree that T stops are nice to know, but only if they're accurate. I can believe that high end purpose huilt cine lenses like Angenieux, Arri Zeiss and Cooke design with that in mind and label accurstely, but many of the rehoused lenses I do not believe. For example every Rokinon lens has a T stop rated exactly 1/3 of a stop slower than the F stop wide open. Then for the rest of the stopped down spertures they don't adjust them at all from the F stops. I think that the cine Sigma and Zeiss CP.2's are similar.
F stop doesn't give me blur because 24mm f2.8 has less blur than 50mm f2.8. F stop number give shutter speed to me. When I want to know blur, I have to divide focal length by f stop number, consider distance between subject and background and working distance. There has good information in your video too. Thx
As always, thank you for the great technical information. But because of the individual differences in F stops and T stops on lenses, it makes it seem that expensive light meters are not so useful.
Or like a pro, we calibrate our meters to our camera/lens combo. My internal camera will not tell me what I need to set for my commercial work. Btw, f-stop tell you depth of field, background blur is a secondary effect.
Great video! One question, so the f is for depth of field and T for the light that comes in the camera, but are they both changed by the type of sensor used with?
Hey Tony totally off topic but the cord on ur mic u might wanna give it some slack at the connector it seems to be under stress! don't want to see u lose the awesome audio quality
What are the t-stops for the more common kit lenses that come with lower cost DSLRs, it would be interesting to see just how bad they truly are considering how bad the apertures are to begin with.
6 лет назад
You can check DxOMark for t-stops of those lenses. My Sony 16-50 kit is measured at t 5.2
Hi Tony, I am getting into sports photography, and I am wondering if the Nikon d7200 will work well for indoor and outdoor high school sports. Thank you!!
Wow! Tony, what happened to that Sony A7RII DX0 Mark not being the king of low light video??? I was geeked about it all day at work about watching it when I got off.
Tony & Chelsea Northrup Unbelievable!! Let me guess, the Sony fan boys and/or DXO Mark proponents came out of the woodwork pissed off?!? I assume you may not want to go into details and that's understandable. I know everyone have their own way of how they deal with things, but personally, I would have kept it up there and wouldn't be so persuaded to take it down because of people freaking out. It's your channel and I get it. I was so eagered up to see that video.
Hey Tony! What happens to the T-stop when you crop sensors &/or crop lenses? Another way to ask this is how does crop factors affect T-stops? Also, how does using a speedbooster on an APS-C body change the T-stop of a lens ... say an optically perfect 50mm f/1.2 T/1.2 full frame lens adapted to a Sony a6500 via speedbooster?
Crop factor does not affect the actual focal length, f-stop or t-stop. They are properties of the lens and not the sensor. A speedbooster focuses the light to the smaller sensor so they improve the t-stop. They improve the f-stop as they reduce the focal length.
No, crop factor doesn't change exposure settings, and T-stop is only used for exposure. You'd only need to multiply t-stop by the crop factor if you wanted to understand the approximate amount of noise in your final image compared to different sensor sizes.
Hey Tony, i looked on DXOMark and now I'm confused. Can you explain why does the same lens has a different T stop on different camera body of same brand and same sensor size? For example Sigma 18-35mm F1.8 on Nikon D7000 has T1.9 and Nikon D500 T2.3. That's 0.4 T stop difference.
Could it be that some cameras cheat a bit with their iso sensitivity so the exposures are actually a bit darker than they should be at a given iso? I know that t stop is a property of the lens and does not have anything to do with the sensor but maybe they tried to measure t stop by looking at how bright the exposure turned out in the camera?
Educational as always please can you make us a list about weather sealed lens? the best of them? and about weather sealing in general,cant find that nowhere,plus many sigma art series isnt ws ,so alternatives at good price?
the T stop change when a full frame lens is mounted on a crop sensor , when I mounted a 17-50mm sigma lens on canon APSC and 70-200 on the same I noticed a huge difference in light . The 17-50 f 2.8 was so bright and the 70-200 f2.8 was relatively dark . did anyone noticed this
Thanks for this Tony, somewhat related question. For image stabilization why do they say its "2 stops" or "5.5 stops" of stabilization? In practice it seems that it allows me to use a lower shutter speed hand held, so for example if R rule says the safe place to start is using shutter speed of 250 but if I had 1 stop of stabilization it would be safe to start at 125 and two stops would be 62.5 (60)? etc.. Is that how I should be looking at it? Cheers, Mitch
Tony, Skillshare don't want to give me two months trial! I need to buy at least one month sub, they ask for my credit card info no matter i click link in description and apply Your code. For me, maybe i am wrong, but FOR ME, two months of free trial mean that i can use some service for two months and IF I LIKE IT, i can buy sub for more period of time. So this is not free trial, this is "Buy one month and get two months free"! Otherwise, i don't see point of storage someone credit card info if maybe that card wouldn't be applied.
So a t-stop is actually a TRANSMITTED stop, versus the measurement that is used to obtain an F/stop. And the F/ means, ah, what exactly then? All the years, never thought to ask.
Thanks so much for this information! It cleared up some questions I had. However it brought up a new one. I have a 1.6x crop body and am thinking of purchasing the canon 300mm L f4 t4.6 IS for bird photography. When multiplying the f-stop and focal length, do I also multiply the t-stop by 1.6?
If you want to compare to full frame results then yes but if you have only a crop body then why bother. Learn to use the camera you have and not the one you do not have.
Hi Tony, Recently I made a test, and I would like to hear your thoughts about that. I used all manual settings and I shoot on ISO 1000 and I used the flash, and I was only changing the flash power while all the rest of the settings were the same (basically I was just adding or reducing the light in the scene). I realized that even though the ISO was always on 1000 the noise was not always the same, it was actually adding more or less, depending of how much light was there in the room(flash). Basically even though I had the ISO set to 1000, with the low flash power it felt more like ISO 6400, whereas when I used more flash power it felt more like ISO 1000 or less. In conclusion I realized that the light is the most important thing and that this will decide of how much noise of ISO we will have in the image, therefore even though we use lets say ISO 1000 there will be always different amount of noise, depending of how much light we have in the scene. Please correct me if I am wrong.?
Something I'm curious about is the relationship between low-light performance and the size of the sensor, And if the T-stop adds any additional calculations based on sensor size. - I assume not, because the amount of light coming out of the lens would not change based on sensor size. I think low-light performance is more related to pixel density, but I'd rather get clarification from an expert - for example, the 5Ds and the 7Dm2 seem to have similar pixel densities, so I assume they have similar low-light performance regardless of their 2 different sensor sizes, correct? In my real-world use case, I have a 7Dm2 sigma 18-35 and 50-150 OS (Since March 2015, at Tony's recommendations, thank you!) which I have been very happy with and used for photographing Antarctica, many trekking adventures in inclement weather, and several paid conference events (I'm not professional, but the clients felt my service was professional and were very happy with the results) ...But I'm planning to sell everything and change to a GH5 (Because: sensor stabilization, touch and flip screen, wireless capabilities, smaller size), And I'm worried if I can use this smaller sensor camera in the same low-light conference environments as I use my 7Dm2, and get the same or better results. Of course lenses are a critical factor, and I'll choose the correct lenses with good or the best T-stop performance - but how can I estimate by how much my results will differ from my current camera, on this smaller system, in terms of light/noise? And then, what can I do to minimize those differences?
M. Robert Marks just hang on with 7d mark 2 sir, and stick with lens stabilization, i think they are already the best, except you want to go to more video than photo...
Correct, I am expanding my skills into video. I'm shooting a music video for a popular European reggae singer this weekend with my 7Dm2 and sigma 18-35 (in the poring rain ^_^), and I'm thinking I would appreciate a weather-sealed camera with a stabilized sensor and 4K down-sampling. - - - coincidentally, < Three Blind Men and An Elephant Productions > just came out with an excellent video questioning the value of the GH5, namely the autofocus. - - - I agree Canon lenses are great, and I think the 7Dm2 is actually a great camera for video, if it's completely stable (because there's no extra room/resolution to correct a shaky video), but I don't have the means to invest in 2 systems, nor would I want that much gear (I already have too much, haha).
I want to say thank you SO MUCH for pronouncing ISO correctly. I know it's something very small, but please WHY DO SO MANY PHOTOGRAPHERS, even the professionals, PRONOUNCE IT WRONG?? >_
I wasnt aware there was a 'correct' way to pronounce ISO? I thought it was just the abbreviation of "International Standards Organization" so why does it matter if you say I.S.O. or Isew. Im I right or wrong?
Sid Bonkers you are correct. ISO is an abbreviation and doesn't have a "pronunciation," it's just become part of the vernacular among people into cameras. This kid just doesn't know it yet. I don't blame him entirely, he does look kinda young. Although I do wonder how he'd pronounce the abbreviation for the American Standards Association. Assah? Lol
Steven P the more correct pronunciation would actually be I-S-O. Because it is an abbreviation. Unless there is some other pronunciation that you are talking about. And even then you'd have to take their accent into account. Actually, from a linguistics standpoint, I don't know if it is technically possible to "mispronounce" because it is only two vowels and a consonant.
Sorry guys, but you're not quite correct, for there is NO such thing as 'International Standards Organization.' It doesn't exist. What you're actually referring to is the 'International Organization for Standardization.' So as you can see, if it really was an abbreviation, it should be 'IOS.' But it's not. ISO it's an actual word that's spelled in all caps.
Time to force the manufacturers to always show the T stop value then? PS: DXOmark does not have all the lenses. For example the Nikor 200-500 f 5.8 was never tested
I would rather know f stop than t stop. f stop tells me what my photos will look like and a bit about how well my lens will work with my auto focus system, and a good approximation of the iso setting. T Stop only tells me about the iso setting, but doesn’t mean that much by itself as an f1.4 t 1.4 lens might have a 2 stop vignette which you have to raise in post adding back noise. Also f stop isn’t really a technology term, it’s a physics/mathematical term, and 150 years is nothing in maths and science.
Bowie Sensei It's not a question of one or the other. We need to know both values. And wouldn't a vignette lower the t stop value or is it only the brighness in the middle of the frame that counts?
I want to know both too, but the impression i got from the video is that Tony didn’t think much of f stops, that they are out of date and that t stops are better to know. T stop is measured from the middle.
Bowie Sensei you are absolutely right about the last point.
6 лет назад
I think t-stops are more important for filmmakers, especially for cinematographers who must know really really well the lenses they're using, in order to both decide the dof and the look they want and prepare other things on set like ambient and artificial lights. That's why all cine lenses have t-stops instead of f-stops marked on them
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YOU GUYS HELPED ME PASS MY FAA 107 WITH A 90!!! thanks
I think it is a lot better when a youtuber advertises sponsors himself within the video than watching the automated ads with their intrusiveness, their increased volume and their unrelated commercial
Hate to admit how long I've been a photographer, but your video did a good job of explaining f/stops. I think those who didn't cut their teeth on "old school" f/stops can appreciate the optical effects an aperture can produce (bokeh), and understand T-Stops if they equate the "T" to light Transmission, which accounts for the variance of brightness you mentioned. As for how it affects different sensor sizes, I'm pretty sure there is more to it than filters or lens coatings or pixel density since in today's cameras so much of the image quality is the result of what the image processing software built into the firmware does.
This video was news to me. I had never heard of T-Stops before prior to reading the title to this video. I was thinking that T-Stpps were derived to British tea time going into this video. Now I am probably going to check for the T-stops for the lenses I own to see where they each stand and see if I need better lenses. This may help when taking pictures in low light situations or want more light to capture things.
Interesting topic Tony, but you leave me wondering if this can be used to my advantage, like using the Sony STM for outdoor portraits. You can get the bokeh of f/2.8 while shooting at T/5.6 - like a built in ND filter.
This can never be an advantage because it is one way change. You can always add a Nd filter but you can never recover the detail lost due to stop lost.
Yes you can get the shallower depth of field without overexposing the image on sunny days. When there is less light of course you pay the price with more noise
It's technically impossible to have the F stop and T stop identical. The biggest reason for the difference is usually the amount of elements the light has to pass through. The quality of the elements, their configuration, coatings and other glass additives will also affect light transmission. As a general rule prime lenses tend to have closer f stop/ T stop ratings than zooms mainly because they have less elements given their simpler design. I do think however that all lenses should show both the F stop and T stop.
Probably the best argument for metering TTL vs. external metering ever made.
Gosh Tony, why do your nerdy videos have to be so good.
The best explanation I have seen on the difference between f and t stops, awesome video.
Big thanks for this video. Never have I heard about T stops before, even thought I've been a photo and video enthusiast for over 10 years now.
Great explanation! Leaves no questions.
Never heard of t-stops before. Awesome video.
Good video. Great examples. Well presented.
Thx Tony, simple explanation of F vs T-Stops! This topic has got a lot of press lately. Like you said "it's 150 year old technology that is not truly relevant in today's digital world! So it is very confusing for many especially since Photography crossed into the Video world. I think in the near future all manufactures with start listing both F & T-Stops on lenses, unless it is a specific Cine lens.
Very good explanation as usual.
As a Sony A7 owner I'd love to see more video related uploads. Keep up the great work - cheers.
It would be worth mentioning that the 100mm STF lens has this deviation between f-stops and T-stops due to the apodization filter, which is intentional.
Mark Pitsilos yup lol was waiting for him to say that but he never did :/ now who's misleading northrup! ;) 😎🤣
Wouldn't say the video was misleading, just an addition that could have been made to show that Sony didn't get all ethical with this lens and decided to come clean with the T-stop :-P
A manufacturer can't really get away with not stating the T-stop for STF lenses anyway.
Mark Pitsilos you would have to be an idiot to buy the 100 2.8 over the 24-70 2.8
hmm but such a large difference, compared to Fujinon XF 56mm F1.2 R APD whihc also has apodization filter, but it has minor light loss.. 1.2 = 1.7 1.4=1.8 2=2.3 2.8=3 4=4.2 5.6=5.6. and the light loss only applies up to F4, after that it's the same.
Granger did this in 2013 with the exact same analogy to cars.
Very good explanation. Thanks.
Terrific video on a very interesting topic. Now I finally know how to read the DXO Mark T Stop thingy. ;)
Glorious. Such an educational video. I have learned on this day! Thank you and happy birthday.
I think the reason for the lack of a switch from f-stops to T-stops for photographers is basically due to marketing. Having the true transmittance of a lens made available to the public might put off people from buying them, especially since most of these lenses have such different f-stops and T-stops in a single lens.
Putting both values - or just the T-stop - on photography lenses would make them even more expensive to manufacture and to buy, since the transmittance of the glass would have to be drastically improved, maintained and controlled.
Great video. Very informative. Big Thumps up
Well, one reason why photographers might still use f-stops, is because when you had the old film days of shooting video, they NEEDED to know that the lenses performed the same in regards to the light pass-through (therefore using T-stops), but in photography, half a stop or even a quarter of a stop oflight is well spent, if you can have a wider aperture and therefore shallower depth of field... So it still makes sense for photographers to use the f/ value, because in our case (especially today), it has a bigger impact on the final result. Still, it would be great to know the T-stop of the lens, so manufacturers should include that in the product details ...
Great clarification. The difference between the new Sony 85mm and the considerably more expensive G-Master is quite telling.
Thanks a lot. Very interesting and valueble information.
How are you doing your experimentation to figure some of these differences out, not only in this, but other videos as well? In this case did you look it up on dxomark or did you figure it out yourself? As a software developer I love the amount of science you bring to all of your videos and tutorials, but lately have been wondering how you figure this stuff out.
Buddy Lindsey great question, I have been wondering the same. I'd love to see a video where Tony and Chelsea show how they do the testing that they often mention in their videos.
I'm guessing that he got the T-stop of a lens in which he used in comparison to the other. He mentioned the Mitakon f0.95 lens against the Canon 50mm f1.4 (ADDED: He may have meant the 35mm F1.4, but my argument stays the same). The Canon F1.4 has a T-stop of 1.6. So if the Mitakon looks about the same in exposure to the Canon but just a smidge brighter... Well, you too could probably make an educated guess.
You can measure the differences with a light meter.
Thanks for the informative video!
Finally an explanation of why nothing makes sense and how what you think you know is wrong!
Nice job Tony
I'm no expert, but it seems to me that a higher t-stop number may not necessarily be a bad thing. Lens manufacturers use coatings on the lenses to improve properties like chromatic aberration, at the cost of absorbing some light. So even though you might be getting a slightly dimmer image, it may look better overall. Just a thought. I'm open to ideas.
This is brilliant, thanks!
than you so much for this video! so much info packed.
Never heard about this. Really useful information. Thanks 👍
Thank you so much Tony! im really glad with your tutorials!
This was very informative. Thank you.
Some people don't know the difference between f and t stops and blame their flash for overrating its GN. I always need to explain this concept to them.
Excellent video. Thanks!!! Does this explain why manufactureres advertise their cameras as having the ability to work at high ISO when in fact the results are disappointing and marred by high levels of grain?
Great info, thanks!
Great video, and thanks for the information..:)
Best video on the matter
Say f-stops if talking about DoF and t-stops if talking light sensitivity. I'd say there is a case for using both. Manufacturers ought to list both for their lenses.
Oh and we should probably also mention that the Sony STM lens has such a high T-stop number because that's how STM lenses are.
A better example of the same lens in both versions would probably be the Samyang 85mm F/1.4. It's just called the Samyang 85mm T/1.5 but is identical apart from the declicked T-stop ring and a cine-focus ring.
Tony I really enjoy your channel. Has anyone ever pointed out your speech pattern/delivery is very similar to Jeff Goldblum.
another awesome video
Hey Tony and Chels!
Are you guys going to be coming to Australia for VidCon in September? :)
Would love for you guys to be there :)
It would be nice to add links you mentioned in the videos description.
The Angenieux 28-340mm is actually an F 2.9 T 3.4. I agree that T stops are nice to know, but only if they're accurate. I can believe that high end purpose huilt cine lenses like Angenieux, Arri Zeiss and Cooke design with that in mind and label accurstely, but many of the rehoused lenses I do not believe. For example every Rokinon lens has a T stop rated exactly 1/3 of a stop slower than the F stop wide open. Then for the rest of the stopped down spertures they don't adjust them at all from the F stops. I think that the cine Sigma and Zeiss CP.2's are similar.
F stop doesn't give me blur because 24mm f2.8 has less blur than 50mm f2.8. F stop number give shutter speed to me. When I want to know blur, I have to divide focal length by f stop number, consider distance between subject and background and working distance. There has good information in your video too. Thx
Thank Tony very interesting never knew this.
As always, thank you for the great technical information. But because of the individual differences in F stops and T stops on lenses, it makes it seem that expensive light meters are not so useful.
Yep! We've covered this in the past here: ruclips.net/video/IsWGkUT5A_Y/видео.html
Thank you for clarifing this. This whole thing of fstop and then the focus breathing is so misleading.
Or like a pro, we calibrate our meters to our camera/lens combo. My internal camera will not tell me what I need to set for my commercial work. Btw, f-stop tell you depth of field, background blur is a secondary effect.
Really like your geeky videos. If there was a Big Bang Theory for the photography world you could star. I mean that in a good way.
Great, thanks! Good info!
THIS OPENED MY EYES WHAAAT
Does the crop factor apply to the T/stops too?
Most of my pics using the sunny f/16 rule were underexposed and didn't know why. When l became aware of t stops, l knew why.
Nice story telling. you did good to make such a boring topic relevant again. thumbs-up
9:08 the one on the right actually blurred the background more I think. Didn't you say the bokeh is the same, but it gathers less light ?
Great video! One question, so the f is for depth of field and T for the light that comes in the camera, but are they both changed by the type of sensor used with?
How do older lenses compare with newer ones for f-stop vs t-stop similarity i.e. do older lenses let more light in?
Hey Tony totally off topic but the cord on ur mic u might wanna give it some slack at the connector it seems to be under stress! don't want to see u lose the awesome audio quality
What are the t-stops for the more common kit lenses that come with lower cost DSLRs, it would be interesting to see just how bad they truly are considering how bad the apertures are to begin with.
You can check DxOMark for t-stops of those lenses. My Sony 16-50 kit is measured at t 5.2
Hi Tony, I am getting into sports photography, and I am wondering if the Nikon d7200 will work well for indoor and outdoor high school sports. Thank you!!
Wow! Tony, what happened to that Sony A7RII DX0 Mark not being the king of low light video??? I was geeked about it all day at work about watching it when I got off.
I'll probably re-post it. People were freaking out.
I'll probably re-post it. People were freaking out.
Tony & Chelsea Northrup Unbelievable!! Let me guess, the Sony fan boys and/or DXO Mark proponents came out of the woodwork pissed off?!? I assume you may not want to go into details and that's understandable. I know everyone have their own way of how they deal with things, but personally, I would have kept it up there and wouldn't be so persuaded to take it down because of people freaking out. It's your channel and I get it. I was so eagered up to see that video.
It would be very nice if they used this T stop system for all lenses.
when will you be in Thailand?
Hey Tony! What happens to the T-stop when you crop sensors &/or crop lenses? Another way to ask this is how does crop factors affect T-stops? Also, how does using a speedbooster on an APS-C body change the T-stop of a lens ... say an optically perfect 50mm f/1.2 T/1.2 full frame lens adapted to a Sony a6500 via speedbooster?
Crop factor does not affect the actual focal length, f-stop or t-stop. They are properties of the lens and not the sensor. A speedbooster focuses the light to the smaller sensor so they improve the t-stop. They improve the f-stop as they reduce the focal length.
Tony, so when a FF lens is used on a crop frame sensor, would the T-stop, (if you knew it), have to be multiplied by the crop factor too?
No, crop factor doesn't change exposure settings, and T-stop is only used for exposure. You'd only need to multiply t-stop by the crop factor if you wanted to understand the approximate amount of noise in your final image compared to different sensor sizes.
Hi, thanks for all the excellent videos. My DSLR camera says it can autofocus a lens with a max aperture of f/8 or bigger. Does it mean f/8 or t/8 ?
Thanks Tony, it always confused me.
Hey Tony, i looked on DXOMark and now I'm confused. Can you explain why does the same lens has a different T stop on different camera body of same brand and same sensor size? For example Sigma 18-35mm F1.8 on Nikon D7000 has T1.9 and Nikon D500 T2.3. That's 0.4 T stop difference.
Different sensor's microlenses.
A wild guess here: the range of sensor-to-lens does matter. Or, the number of pixels matters.
If anyone does really know, I'd like to hear it though
Interesting! Looks like they just have a big margin of error measuring T-Stops. T-Stops should be the same regardless of the camera body.
Could it be that some cameras cheat a bit with their iso sensitivity so the exposures are actually a bit darker than they should be at a given iso? I know that t stop is a property of the lens and does not have anything to do with the sensor but maybe they tried to measure t stop by looking at how bright the exposure turned out in the camera?
Ilie Mirauti We know, we are just discussing potential errors in their testing methods...
So does the difference between F and T stop remain constant throughout the Aperture range?
Educational as always please can you make us a list about weather sealed lens? the best of them? and about weather sealing in general,cant find that nowhere,plus many sigma art series isnt ws ,so alternatives at good price?
one question: T-stops has the same stop value as F-stops? Example doubling the value 0.95-1.4-2-2.8-4-5.6
Simply check DXOmark for the T stops of most lenses.
What do the letters "f" and "T" stand for? Are they shorthand for certain words? If you know, please explain. Thanks.
F stands for the focal length. The aperture is focal length divided by the value so it is written f/1.8 T stands for transmission.
Thank you
cant find T stop for Fuji lenses. do you know what site can help me about it?
By the way, the 100mm GM is a STF lens, not a STM lens.
Aaron Yang "smooth transition focus"
the T stop change when a full frame lens is mounted on a crop sensor , when I mounted a 17-50mm sigma lens on canon APSC and 70-200 on the same I noticed a huge difference in light . The 17-50 f 2.8 was so bright and the 70-200 f2.8 was relatively dark . did anyone noticed this
A crop sensor just crops the middle part of the image like you could crop on post processing so I do not see how it could affect brightness.
Thanks for this Tony, somewhat related question. For image stabilization why do they say its "2 stops" or "5.5 stops" of stabilization? In practice it seems that it allows me to use a lower shutter speed hand held, so for example if R rule says the safe place to start is using shutter speed of 250 but if I had 1 stop of stabilization it would be safe to start at 125 and two stops would be 62.5 (60)? etc.. Is that how I should be looking at it? Cheers, Mitch
Mitchell Hagerty Yes that's right
Is T-stop stay constant for example at f/1.8 and f/5.6?
Not necessarily... but if the T-stop shows a loss of light at f/1.8 it'll also show a loss at f/5.6.
Can you please review both Sony lenses. Thanks
in skillshare if I signup and fill the credit card information would it cost charges automatically after 2 months free trial?
This is sooo geeky, im scary that i liked that haha!
Tony, Skillshare don't want to give me two months trial! I need to buy at least one month sub, they ask for my credit card info no matter i click link in description and apply Your code. For me, maybe i am wrong, but FOR ME, two months of free trial mean that i can use some service for two months and IF I LIKE IT, i can buy sub for more period of time. So this is not free trial, this is "Buy one month and get two months free"! Otherwise, i don't see point of storage someone credit card info if maybe that card wouldn't be applied.
So a t-stop is actually a TRANSMITTED stop, versus the measurement that is used to obtain an F/stop. And the F/ means, ah, what exactly then? All the years, never thought to ask.
Thanks so much for this information! It cleared up some questions I had. However it brought up a new one. I have a 1.6x crop body and am thinking of purchasing the canon 300mm L f4 t4.6 IS for bird photography. When multiplying the f-stop and focal length, do I also multiply the t-stop by 1.6?
If you want to compare to full frame results then yes but if you have only a crop body then why bother. Learn to use the camera you have and not the one you do not have.
It would also be worth mentioning that it *is* possible to get a lower T-stop value than F-stop. Speedboosters do exactly that.
True, but speedboosters also lower the f/stop by the same factor.
Hey Tony, are you going to review the Sony GM 100F28GM ?
Yep, we've been working on it. It should be out next week.
matt granger deja vu :)
Hi Tony,
Recently I made a test, and I would like to hear your thoughts about that. I used all manual settings and I shoot on ISO 1000 and I used the flash, and I was only changing the flash power while all the rest of the settings were the same (basically I was just adding or reducing the light in the scene). I realized that even though the ISO was always on 1000 the noise was not always the same, it was actually adding more or less, depending of how much light was there in the room(flash). Basically even though I had the ISO set to 1000, with the low flash power it felt more like ISO 6400, whereas when I used more flash power it felt more like ISO 1000 or less. In conclusion I realized that the light is the most important thing and that this will decide of how much noise of ISO we will have in the image, therefore even though we use lets say ISO 1000 there will be always different amount of noise, depending of how much light we have in the scene. Please correct me if I am wrong.?
Do you anybody know where I can find the T stop values of Fuji lenses?
Something I'm curious about is the relationship between low-light performance and the size of the sensor, And if the T-stop adds any additional calculations based on sensor size. - I assume not, because the amount of light coming out of the lens would not change based on sensor size. I think low-light performance is more related to pixel density, but I'd rather get clarification from an expert - for example, the 5Ds and the 7Dm2 seem to have similar pixel densities, so I assume they have similar low-light performance regardless of their 2 different sensor sizes, correct? In my real-world use case, I have a 7Dm2 sigma 18-35 and 50-150 OS (Since March 2015, at Tony's recommendations, thank you!) which I have been very happy with and used for photographing Antarctica, many trekking adventures in inclement weather, and several paid conference events (I'm not professional, but the clients felt my service was professional and were very happy with the results) ...But I'm planning to sell everything and change to a GH5 (Because: sensor stabilization, touch and flip screen, wireless capabilities, smaller size), And I'm worried if I can use this smaller sensor camera in the same low-light conference environments as I use my 7Dm2, and get the same or better results. Of course lenses are a critical factor, and I'll choose the correct lenses with good or the best T-stop performance - but how can I estimate by how much my results will differ from my current camera, on this smaller system, in terms of light/noise? And then, what can I do to minimize those differences?
M. Robert Marks just hang on with 7d mark 2 sir, and stick with lens stabilization, i think they are already the best, except you want to go to more video than photo...
Correct, I am expanding my skills into video. I'm shooting a music video for a popular European reggae singer this weekend with my 7Dm2 and sigma 18-35 (in the poring rain ^_^), and I'm thinking I would appreciate a weather-sealed camera with a stabilized sensor and 4K down-sampling. - - - coincidentally, < Three Blind Men and An Elephant Productions > just came out with an excellent video questioning the value of the GH5, namely the autofocus. - - - I agree Canon lenses are great, and I think the 7Dm2 is actually a great camera for video, if it's completely stable (because there's no extra room/resolution to correct a shaky video), but I don't have the means to invest in 2 systems, nor would I want that much gear (I already have too much, haha).
I want to say thank you SO MUCH for pronouncing ISO correctly. I know it's something very small, but please WHY DO SO MANY PHOTOGRAPHERS, even the professionals, PRONOUNCE IT WRONG?? >_
I wasnt aware there was a 'correct' way to pronounce ISO? I thought it was just the abbreviation of "International Standards Organization" so why does it matter if you say I.S.O. or Isew.
Im I right or wrong?
Sid Bonkers you are correct. ISO is an abbreviation and doesn't have a "pronunciation," it's just become part of the vernacular among people into cameras. This kid just doesn't know it yet. I don't blame him entirely, he does look kinda young. Although I do wonder how he'd pronounce the abbreviation for the American Standards Association. Assah? Lol
Steven P the more correct pronunciation would actually be I-S-O. Because it is an abbreviation. Unless there is some other pronunciation that you are talking about. And even then you'd have to take their accent into account. Actually, from a linguistics standpoint, I don't know if it is technically possible to "mispronounce" because it is only two vowels and a consonant.
Sorry guys, but you're not quite correct, for there is NO such thing as 'International Standards Organization.' It doesn't exist.
What you're actually referring to is the 'International Organization for Standardization.'
So as you can see, if it really was an abbreviation, it should be 'IOS.' But it's not. ISO it's an actual word that's spelled in all caps.
The sdp.io/abel link (referenced at 13:26) doesn’t lead anywhere. Is that intentional?
Sorry about that, I added the link.
Time to force the manufacturers to always show the T stop value then?
PS: DXOmark does not have all the lenses. For example the Nikor 200-500 f 5.8 was never tested
How do you go about determining T stops on a lens? Did I miss it?
mavfan1 Guess not. I'll try again
I would rather know f stop than t stop. f stop tells me what my photos will look like and a bit about how well my lens will work with my auto focus system, and a good approximation of the iso setting. T Stop only tells me about the iso setting, but doesn’t mean that much by itself as an f1.4 t 1.4 lens might have a 2 stop vignette which you have to raise in post adding back noise. Also f stop isn’t really a technology term, it’s a physics/mathematical term, and 150 years is nothing in maths and science.
Bowie Sensei It's not a question of one or the other. We need to know both values. And wouldn't a vignette lower the t stop value or is it only the brighness in the middle of the frame that counts?
I want to know both too, but the impression i got from the video is that Tony didn’t think much of f stops, that they are out of date and that t stops are better to know. T stop is measured from the middle.
Bowie Sensei you are absolutely right about the last point.
I think t-stops are more important for filmmakers, especially for cinematographers who must know really really well the lenses they're using, in order to both decide the dof and the look they want and prepare other things on set like ambient and artificial lights. That's why all cine lenses have t-stops instead of f-stops marked on them