[amoringello]

Are your referring to neolithic pre-chickens?
Cause I'd rather talk about neolithic pre-chcikens than DOF right now.

Would that be an African or European neolithic pre-chciken?

[normhead]

Who are these people that you're insulting? I want to meet one of them.

There would be nothing more damaging to my psyche than trying to go back through the thread to find out who there were. But there has been a long evolution to get to this point. And besides, I'm sure you know who they were. Look ahead to the future. I think we've got it pretty much locked down now.

---------- Post added 07-16-15 at 12:29 PM ----------

Would that be an African or European neolithic pre-chciken?

I tend to specialize in African, since the European ones all were brought to Europe in little African pre-chicken cages during the great human migration out of Africa.

[ElJamoquio]

Well, yes and no. I'm not sure what the effect of stitching is. Is Stiching two 35mm images together the same as one 17mm image? Because a 17mm lens would give you way more DoF than a 35 mm lens.

If you had enough images, etc., the picture would be the same. Equivalence never fails.

---------- Post added 07-16-15 at 09:57 AM ----------

There would be nothing more damaging to my psyche than trying to go back through the thread to find out who there were. But there has been a long evolution to get to this point. And besides, I'm sure you know who they were. Look ahead to the future. I think we've got it pretty much locked down now.

That wasn't directed at you, but no, I'm not sure who 'they' are. I certainly couldn't name a single one.

---------- Post added 07-16-15 at 09:59 AM ----------

DOF again is created by Focal length, Aperture and Distance to subject. Each image will have the same DOF, regardless of how many you stitch together. Just as if you have a 1mm x 1mm sensor or a 1meter by 1meter sensor, the DOF does not change.

Equivalent focal length changes, and you would view the image at a different magnification.

It's all very simple if you use equivalence, and all very difficult if you do not.

[boriscleto]

Are your referring to neolithic pre-chickens?
Cause I'd rather talk about neolithic pre-chcikens than DOF right now.

Is that the same thing as dinosaurs?

[wombat2go]

Is that the same thing as dinosaurs?

Actually dicnosaurs. Its all equivalence, you know.

[osv]

DOF == Aperture, Focal length and Distance to Subject.
WHY WHY WHY do people continue to change a defining attribute of DOF, such as distance, and explain it away as the sensor being the culprit??

This is a prime example of the pure FAIL in these arguments when people do not fully comprehend what it is that they are talking about.

lol... beyond that, the effects of cropping on dof:

"DOF is determined by subject magnification at the film / sensor plane and the selected lens aperture or f-number. For a given f-number, increasing the magnification, either by moving closer to the subject or using a lens of greater focal length, decreases the DOF; decreasing magnification increases DOF. For a given subject magnification, increasing the f-number (decreasing the aperture diameter) increases the DOF; decreasing f-number decreases DOF.

If the original image is enlarged to make the final image, the circle of confusion in the original image must be smaller than that in the final image by the ratio of enlargement. Cropping an image and enlarging to the same size final image as an uncropped image taken under the same conditions is equivalent to using a smaller format under the same conditions, so the cropped image has less DOF. (Stroebel 1976, 134, 136–37)."

[shakumar]

that is wrong, and we've covered the reasons why about a million times already

you don't get "more dof" with any format... not aps-c, not m4/3, not ff, etc.

if you want to compare formats, ignore the printed number on the lens barrel, and compare only light, dof, and fov.

Are you saying that regardless the sensor / film size, you will get the same exact depth-of-field perceived in the image using a lens with the same focal length and aperture size?

I could be living in a completely different universe than yours, but that is not how things are in mine

[normhead]

Actually dicnosaurs. Its all equivalence, you know.

Do big dinosaurs make more noise than half pint dinosaurs?

---------- Post added 07-16-15 at 03:55 PM ----------

It's all very simple if you use equivalence, and all very difficult if you do not.

But it's better for your photography, if you shoot at multiple ƒ-stops and select the one you like. There's a formula for equivalence, but there's no formula to help you select how much DoF you're shooting for. Doing that for 2 formats would be double the work.

[amoringello]

Are you saying that regardless the sensor / film size, you will get the same exact depth-of-field perceived in the image using a lens with the same focal length and aperture size?

I could be living in a completely different universe than yours, but that is not how things are in mine

Very simple to find out:
Take a photo with your FF camera.
Now take some black tape and mask off part of your sensor.
Take the same photo.

What do you get?
Don't need to actually damage your camera with gooky tape, just think about it.
How does the mask you created change the light coming from the lens?

If someone can find that the tape alters and warps light coming from the lens, they've discovered a pretty wonderful alternate universe and could probably even create worm-holes with their mind.

[boriscleto]

Do big dinosaurs make more noise than half pint dinosaurs?

T-Rex, Giant Death Chicken.

[normhead]

The part when you are talking about, back in the beginning, was "for pictures of the same size."

If you print your FF image and then mask off the APS_c sensor, they will obviously have the same DoF. They are the same print, it has to be. Say you have a ruler in there printed at life size. And the DoF is six inches of the ruler in focus.

Expand the APS-c image so the image is twice the size equivalent to the whole size of the FF original, and the amount of image in clear focus will be 12 inches, even though it will only cover size inches in markings on the ruler. The rule is twice the size.

Is that kind of it? Am I getting close?

I'm already wishing I'd stayed on the chicken dinosaurs theme.

[amoringello]

lol... beyond that, the effects of cropping on dof:

"DOF is determined by subject magnification at the film / sensor plane and the selected lens aperture or f-number. For a given f-number, increasing the magnification, either by moving closer to the subject or using a lens of greater focal length, decreases the DOF; decreasing magnification increases DOF. For a given subject magnification, increasing the f-number (decreasing the aperture diameter) increases the DOF; decreasing f-number decreases DOF.

If the original image is enlarged to make the final image, the circle of confusion in the original image must be smaller than that in the final image by the ratio of enlargement. Cropping an image and enlarging to the same size final image as an uncropped image taken under the same conditions is equivalent to using a smaller format under the same conditions, so the cropped image has less DOF. (Stroebel 1976, 134, 136–37)."

Stop moving closer to the subject and changing one of the primary defining properties of DOF!
Stop changing the focal length, again changing one of the primary defining properties of DOF!
Until there is an understanding how DOF is perceived on the sensor plane, the rest of the statements are useless.

Once you keep the primary factors consistent, only then you can then start talking about what it means to create an "equivalent image" from that. How it changes in cropping FF down to the Cropped portion, or magnifying the Cropped image unto the FF size. Effects of printing, resolution, substrate, acceptable sharpness, viewing distance and even visual acuity of the individual viewing the image.

---------- Post added 07-16-15 at 04:11 PM ----------

T-Rex, Giant Death Chicken.

NICE! Will I be able to get pictures like that with a FF camera?

[normhead]

NICE! Will I be able to get pictures like that with a FF camera?

Only at ƒ1.4. I you're going to use ƒ5.6 or higher, you may as well use 4/3. Using 4/3 would save a lot of weight, and you could run away faster. This is when understanding equivalence could save your life.

[ElJamoquio]

Doing that for 2 formats would be double the work.

It's double the work if you're not using equivalence. It's an equal amount of work if you do use equivalence.

---------- Post added 07-16-15 at 01:19 PM ----------

you could run away faster. This is when understanding equivalence could save your life.

They like to surprise you at night. You'd never see them through the noise of a shoddy 4/3rds camera.

[Parallax]

NICE! Will I be able to get pictures like that with a FF camera?

Absolutely. Full Feathered cameras are ideal for that.