OK...I am wrong about this calculator...last night I had selected the D5000 with 28mm lens and was looking at Nikon literature for the 28 on 35mm film...Now when you plug in 35mm film, 28mm lens, and focused distance of 15' the calculator says 6.27' to infinity which is what the Nikon brochure says so it is correct so my statement above is wrong. Now that is full frame 35mm film. Interestingly when you plug in D5000, 28mm lens, and focused distance of 15' the computer says 7.78 - 206.5 so the DX is changing something although it seems to be a very minor difference. It appears to be a decrease in DOF does that sound right???
Nikkor 35mm 1.8 G
- Thread starter amonamarth
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OK...I am wrong about this calculator...last night I had selected the D5000 with 28mm lens and was looking at Nikon literature for the 28 on 35mm film...Now when you plug in 35mm film, 28mm lens, and focused distance of 15' the calculator says 6.27' to infinity which is what the Nikon brochure says so it is correct so my statement above is wrong. Now that is full frame 35mm film. Interestingly when you plug in D5000, 28mm lens, and focused distance of 15' the computer says 7.78 - 206.5 so the DX is changing something although it seems to be a very minor difference. It appears to be a decrease in DOF does that sound right???
AperturePriority
New member
No Jeff, it was the mistake of the guy who wrote that calculator's program. He should not apply the crop factors to the calculator for DoF.
DoF of a lens is independent with the formats/image sensors you use. Your 28mm lens has the same DoF as you mount it on a DX or an FX camera. Crop factors take effect to Field of View but not to the DoF of that same lens.
Thereso, if you focus at 15' with f/16, 28mm lens has the same DoF doesn't matter what camera format you mount the lens on. A Canon 5D (FX), or 1D (crop factor 1.3), or a 7D (crop factor 1.6), or a Nikon DX 1.5 will give you the same DoF with it.
Most of the P&S camera have apertures larger than f/8. But they have VERY THICK DoF, because their REAL focals are about 4.5-70mm compare to DSRL cameras have longer lens focals. A lot of photographers like to take macro photos by P&S cameras because of that thick DoF come from them.
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Hi Guys
Many thanks for the response to my question, there is quite a bit to take in so obviously I need to get the lens on the camera and practise and see what works with the lens. When shooting landscapes I have usually focused on the furthest point at infinity on the lens but never really been 100% happy with the picture sharpness.
The lens arrived yesterday (an ebay purchase) listed as almost new, hardly used etc... but was nowhere near the condition quoted. It was also missing the rear cap and the pouch. So its going back! In the meantime I'll get some practise in with my 50mm 1.8 G until I find another suitable 35mm.
Thanks again
John
Many thanks for the response to my question, there is quite a bit to take in so obviously I need to get the lens on the camera and practise and see what works with the lens. When shooting landscapes I have usually focused on the furthest point at infinity on the lens but never really been 100% happy with the picture sharpness.
The lens arrived yesterday (an ebay purchase) listed as almost new, hardly used etc... but was nowhere near the condition quoted. It was also missing the rear cap and the pouch. So its going back! In the meantime I'll get some practise in with my 50mm 1.8 G until I find another suitable 35mm.
Thanks again
John
You are absolutely right, Tu...my mistake. I obviously read the post wrong. My apologies, Jeff. And thanks for correcting me, Tu.
John maybe this explanation will be more clear...
Except when using very close focusing, depth of field extends 1/3 in front and 2/3 behind the point upon which the lens is focused. When focused at infinity, it is logical that 2/3 of the DOF, supposedly beyond infinity is wasted. By refocusing on the nearest limit of DOF, all objects to infinity remain in focus but the DOF has been brought forward to include closer objects as well. When focused on close subjects the DOF is shallow. Now here is the critical part of your question and this is what you are after - focusing for the maximum advantage - By refocusing on the furthest limit of the DOF, the DOF can be increased to include not only the closest subject but also subjects further back.
Except when using very close focusing, depth of field extends 1/3 in front and 2/3 behind the point upon which the lens is focused. When focused at infinity, it is logical that 2/3 of the DOF, supposedly beyond infinity is wasted. By refocusing on the nearest limit of DOF, all objects to infinity remain in focus but the DOF has been brought forward to include closer objects as well. When focused on close subjects the DOF is shallow. Now here is the critical part of your question and this is what you are after - focusing for the maximum advantage - By refocusing on the furthest limit of the DOF, the DOF can be increased to include not only the closest subject but also subjects further back.
I understand what you say regarding the focusing on infinity and that makes good sense. But I am unsure where the furthest limit of the DOF is? Is it at the point where the two meet? (1/3 and 2/3)
Yes...it is the hyperfocal distance which is defined as follows - When a camera is set on infinity, DOF extends from infinity to a point closer to the camera. The distance from the camera to this point is called the hyperfocal distance. Because DOF extends in front of and behind a point focused on, the camera can be refocused for this hyperfocal distance whereupon DOF will extend from half the hyperfocal distance to infinity...that means you maximize your DOF which is crucial to a good landscape shot.
I've never really learned to use it on any camera I've had but my film cameras have a DOF preview button and I suppose it has something to do with helping to find the hyperfocal point but I am not sure.
I've never really learned to use it on any camera I've had but my film cameras have a DOF preview button and I suppose it has something to do with helping to find the hyperfocal point but I am not sure.
Here this diagram by Mr Fox Talbot will help you visualize this concept...
1) If we focus too close the distant part of the image will not be in focus
2) If we focus too far away we are "wasting" some dept of field and giving up focus in the foregroud
3) By calculating the exact hyperfocal distance we make the most of the available depth of field.
1) If we focus too close the distant part of the image will not be in focus
2) If we focus too far away we are "wasting" some dept of field and giving up focus in the foregroud
3) By calculating the exact hyperfocal distance we make the most of the available depth of field.
Your welcome sir and please let me say a big thank you to yourself and AP as I was unfamiliar with the concept myself other than cursory glances at my photography book...I never really grasped it fully until you asked your question and I started studying it.
I'm always learning from other's posts and that is a good thing because it makes me a better photog...cameras are remarkable machines and can be very convoluted indeed!
All this talk about DOF makes me want to throw on the wide angle and go make some landscape snaps!
I'm always learning from other's posts and that is a good thing because it makes me a better photog...cameras are remarkable machines and can be very convoluted indeed!
All this talk about DOF makes me want to throw on the wide angle and go make some landscape snaps!
AperturePriority
New member
No problem, Jack. And, thanks for understanding.You are absolutely right, Tu...my mistake. I obviously read the post wrong. My apologies, Jeff. And thanks for correcting me, Tu.
Michael J.
Senior Member
Great explained