ABJanes Loc: Jersey Boy now Virginia

3. Using Simple Depth of Field Calculator 500MM f/16 from 8' in focus front to back .2" at 13' in focus front to back .7"
1. Using Simple Depth of Field Calculator 200MM f/16 from 8' in focus front 1.7" & back 1.8" at 13' in focus front 4.6" & back 4.8"

Note: Using Simple Depth of Field Calculator 500MM f/16 from 5' in focus front to back .1"

ABJanes Loc: Jersey Boy now Virginia

So stepping back a bit and then cropping/enlarging in post should help. Yes?

amfoto1 Loc: San Jose, Calif. USA

You are correct.

In fact, as you were replying I was expanding my response above, essentially pointing out the same thing as you.

Maybe I'm too old to change... I always think of DoF in terms of aperture, focal length and distance. I guess I just always think in terms of what I can change. And, except for macro work, focal length or distance come to mind a lot more often than magnification. When I'm trying to frame a scene or a subject, I think in terms of how far or near I want to or am able to stand and what lens focal length I want to use to make the image... I don't really get into "what magnification?" very much other than when I'm shooting macro.

Besides, I always wanted to learn to juggle.

But it's correct that the last two... focal length vs distance.... essentially offset each other and equal magnification. As a result it's also correct to say there are two concerns: aperture and magnification.



Well, thanks! That's a big help! I'm sure you really clarified it for everyone.

amfoto1 Loc: San Jose, Calif. USA

It depends.

"Stepping back" while using the same lens simply reduces magnification and there-by increases DoF.

However, cropping too much can quickly spoil images. I always try to keep cropping to a minimum.

How much crop is too much? It depends upon how the image will be used. But, for example, if you crop a full frame image to the equivalent APS-C you're "throwing away" about 60% of the originally captured image data. If your full frame camera is 24MP, you'll only have about 10MP remaining after that crop. If your FF camera is 36MP, the crop only leaves around 15MP. You'd be better off actually using a relatively modern APS-C camera, many of which are now at least 20MP, very often 24MP and sometimes a little higher.

It's only when you are using full frame around 50MP or higher resolution that an APS-C size crops to images will leave about the same as an actual APS-C camera would be able to deliver.

I bet many people don't think of that as a particularly heavy crop. I visualize it with lens focal lengths, such as: a 50mm lens on APS-C "acts like" a 75mm or 80mm on full frame.... an 85mm on APS-C acts like 135mm on FF.... a 135mm on APS-C "acts like" 200mm on FF... etc. When you look at it this way, it seems a moderate crop. But when you look at how much data is actually being thrown away, it's pretty serious.

The reason I use a full frame to APS-C crop example is because the smaller format renders pretty close to 1 stop's worth of additional depth of field. In other words, to render the same DoF and equal background blur that are produced with 75-80mm f/2.8 on full frame you would need to shoot with 50mm f/2 on APS-C. (Note: Lens aperture remains the same as far as exposure is concerned. It only changes how it renders DoF, depending upon sensor format.)

"Stepping back" enough to increase DoF the equivalent of one stop will mean later doing a 60% crop and leaving only around 40% of the data from whatever size sensor you use to take the shot.

Architect1776 Loc: In my mind

How macro are you going?
Or is it more close focusing?
I have used my 100-400mm L MII on bees and other insects at 400mm with very good success and very little cropping as I do like to have a bit of flower or whatever.
Still see the detail in the wings etc. just fine and more DOF than a macro lens.

fetzler Loc: North West PA

DOF is determined by aperture and magnification of the object on the sensor. If you have an image that is 1x on the sensor physics does not know if you have a macro lens or extension tubes; you get the same depth of field.

In general you have two options if you use your equipment - use a smaller aperture or use focus stacking.

Another possibility is to use a small format camera like micro 4/3. A smaller magnification is needed to fill the frame with a object than it would be for a full frame camera.

Macrophotography with medium and large format cameras is possible but very difficult. The swings and tilts on large format camera make life a bit better. Large format cameras are not suitable for small insects however. For an 8x10" camera the human face is a macro shot.

fetzler Loc: North West PA

NO NO NO. Aperture and image magnification on the sensor determine DOF. The focal length of the lens does not matter. Of course longer focal lengths give more working room at a given magnification.

PhotoKurtz Loc: Carterville, IL

Have you experimented with "focus stacking" in PS? I did a bunch of closeups in a light booth that went together very well.

User ID

No. Not in the least. You make no change whatsoever to the final magnification. When magnification doesn’t change, DoF doesn’t either.

Architect1776 Loc: In my mind

The OP stated that stacking is not an option with moving subjects.

User ID

👍👍👍👍👍

“Magnification on the sensor” is better changed to “ultimate image viewing magnification” ... but in this particular context they are lock step linked.

PhotoKurtz Loc: Carterville, IL

Correct. I hadn't read that he was shooting moving objects. Sorry.

User ID

Typical uhh nonsense. That idea will get you nothing. Magnification at the sensor does not affect DoF. There is no actual DoF in on-sensor images. You don’t have any DoF until you have an image for real world viewing. DoF is an illusion and the success of that illusion is determined by viewing circumstance and nothing else.

The DoF scales on classic lenses do not indicate any absolute DoF on the film or sensor. There is no absolute DoF, nor anything even approximating same. The scale indicates the reasonable success of the illusion, given minor cropping and a full page magazine image, viewed at reading distance by average eyesight. It does not apply to postcards, large art gallery prints, or screen images.

The greatest determinant of DoF at any particular aperture is the image viewing circumstance, NOT the on-sensor or the on-film magnification. Illusion is about perception, and perception depends on the perceiver, who is the viewer of the final finished product.

imagemeister Loc: mid east Florida

Yes, I agree with everything you say . But, unlike you, I do think that shooting at a lower magnification with high pixel density and cropping and using well applied pixel enlargement software ( AI) - there is a potential for a perceptible greater DOF. I understand, if you are a purist, you will argue this.
.

fetzler Loc: North West PA

Go a study optics. DOF is determined by aperture and magnification of the object on the sensor or film. It is also true that there is an acceptable circle of confusion that will depend on print size and and viewing distance. Making a smaller print may give the impression of more depth of field. None-the-less all images taken at the same aperture and the same image magnification will have the same perceived DOF when printed and viewed in the same way. Go take a picture of a small insect (you can use a dead one) with a 4 x5" camera. Be sure to fill the frame with the insect. You will get the idea then. Be sure you have a long enough bellows.!!!