Great video… qq - at F4 we get shallow depth of field (blurry background), is that because I’ve focussed somewhere in the foreground? What if I focus on background at F4, will it give me a blurry foreground?
This always confused me. The entire two years I did photography at college, I could never get my head around it. I think I get it now, though, thanks so much for the explanation.
I’m so glad I learned this when I was young and shooting with 35 mm cameras. I’m not sure my senior brain could master the concept if I had to learn it now, LOL! I found many things much easier to learn when I was younger.
Another question - I have a 100-400 mm F4-5.6 lens… I use that to shoot moon aligned with buildings… I also use a 2x teleconverter (basically i lose 2 stops of light) … so w/o teleconverter at 400mm my Fstop is at 5.6 and with 2X convertor it is at F13… so with 2X converter at F13… will my depth of field be same as F5.6 without convertor? Reason I ask is so I can plan my moon shots better… basically drop the convertor and then use lens at F13… then crop the image…
There are some thing you should consider, the F-stop is a calculation of the ratio between the diameter of the aperture(mm) and the focal length. This is done this way so the light measured at e.g. F4 is the same over the range of focal lengths. (which is handy when you change lenzes. An F4 light measurement at 35mm is the same F4 on 85mm). This means that at F4 the actual aperture diameter is smaller at 35mm then on 85mm. This also explains why a photo at 35mm has more DoF then on 85mm when using the same f-number. The diameter of the aperture is smaller on 35mm (and yes DoF is only directly affected by aperture diameter and distance to subject) When you add a teleconverter things get somewhat complicated because you're not adding actual focal length you adding a magnifier, it will magnify the central part of your image to the size of a 35mm film. Which works somewhat differently. So from the point of light. When you shoot at f5.6 you will be getting the same amount of light in as at F11. Which practical means that if you shoot at F11 without the converter and you add the converter: you need to open up to F5.6 (or adjust the iso or shutterspeed) to get the same amount of light in . However the diameter (mm) of your aperture at f.5.6 stil is the same with or without teleconverter. As your aperture size didn't change you would expect the DOF to appear the same after adding the teleconverter. But then the magnification kicks in. Things which would appear in focus unmagnified might appear out of focus when magnified. So your Depth of field decreases at f5.6 with the teleconverter. (That is if you don't change your distance to your subject, which is the case in moonshot) . However the same losing depth of field by magnification applies when you crop your image (you're cutting out a smaller part and blow it up to the original size).
I see the shutter speed dropped more every time you went up an fstop and the iso even increased as you got up to apertures like f16 and f22.Does this have to happen.Its like you have to compensate or something.
I am not sure if my first question got posted and hence adding again… at F4 you get blurry background, is this the case coz you focussed in the foreground? What if at F4 you focussed somewhere in the background, will the foreground be blurry?
After watching this video, there is no more confusion for me. You're great!
Thanks! 😃
I’m brand new to photography and this was hugely helpful! Thank you!
You're welcome Donna 👍
Brilliant. Love this channel 👍🙂
Great to hear Janet 👍
Nice video. One way of thinking about F numbers is if you think of F4 having 4 F's and F22 having 22 F's the more F's the greater depth of field
Cheers Tom 👍
Great video, I am gradually working through them all, very helpful so many thanks
You are welcome Shaun 👍
great video, many thanks
Glad you enjoyed it
Nicely explained Marc
Glad it was helpful!
Thank you! I just bought your book from amazon as well!
Thank you, hope you like it 👍
Very impressive. For that reason I have decided to sign up.
Welcome aboard Kenneth 👍
Good one
Great video… qq - at F4 we get shallow depth of field (blurry background), is that because I’ve focussed somewhere in the foreground? What if I focus on background at F4, will it give me a blurry foreground?
Good explanation 👍
Glad you liked it!
This always confused me. The entire two years I did photography at college, I could never get my head around it. I think I get it now, though, thanks so much for the explanation.
Great to hear!
I’m so glad I learned this when I was young and shooting with 35 mm cameras. I’m not sure my senior brain could master the concept if I had to learn it now, LOL! I found many things much easier to learn when I was younger.
Another question - I have a 100-400 mm F4-5.6 lens… I use that to shoot moon aligned with buildings… I also use a 2x teleconverter (basically i lose 2 stops of light) … so w/o teleconverter at 400mm my Fstop is at 5.6 and with 2X convertor it is at F13… so with 2X converter at F13… will my depth of field be same as F5.6 without convertor?
Reason I ask is so I can plan my moon shots better… basically drop the convertor and then use lens at F13… then crop the image…
There are some thing you should consider, the F-stop is a calculation of the ratio between the diameter of the aperture(mm) and the focal length. This is done this way so the light measured at e.g. F4 is the same over the range of focal lengths. (which is handy when you change lenzes. An F4 light measurement at 35mm is the same F4 on 85mm). This means that at F4 the actual aperture diameter is smaller at 35mm then on 85mm. This also explains why a photo at 35mm has more DoF then on 85mm when using the same f-number. The diameter of the aperture is smaller on 35mm (and yes DoF is only directly affected by aperture diameter and distance to subject) When you add a teleconverter things get somewhat complicated because you're not adding actual focal length you adding a magnifier, it will magnify the central part of your image to the size of a 35mm film. Which works somewhat differently. So from the point of light. When you shoot at f5.6 you will be getting the same amount of light in as at F11. Which practical means that if you shoot at F11 without the converter and you add the converter: you need to open up to F5.6 (or adjust the iso or shutterspeed) to get the same amount of light in . However the diameter (mm) of your aperture at f.5.6 stil is the same with or without teleconverter. As your aperture size didn't change you would expect the DOF to appear the same after adding the teleconverter. But then the magnification kicks in. Things which would appear in focus unmagnified might appear out of focus when magnified. So your Depth of field decreases at f5.6 with the teleconverter. (That is if you don't change your distance to your subject, which is the case in moonshot) . However the same losing depth of field by magnification applies when you crop your image (you're cutting out a smaller part and blow it up to the original size).
I see the shutter speed dropped more every time you went up an fstop and the iso even increased as you got up to apertures like f16 and f22.Does this have to happen.Its like you have to compensate or something.
Hi yes you have to compensate for the light. More details here www.theschoolofphotography.com/courses/beginners-photography-course
I am not sure if my first question got posted and hence adding again… at F4 you get blurry background, is this the case coz you focussed in the foreground? What if at F4 you focussed somewhere in the background, will the foreground be blurry?
Hi, too long to a answer on YT but you'll find the answers here www.theschoolofphotography.com/courses/beginners-photography-course
Sir Isaac Newton- most influential scientist of all time
Marc Newton- best teacher of photography of all time
😁 yep. That about sums it up. 👍🏼
Wow, thanks 😁