Help with crop vs full frame please: I realize this topic has been beaten to death. But I still haven't found a definitive answer. I'm currently shooting a D810. My latest kick is...

Ponz

I realize this topic has been beaten to death. But I still haven't found a definitive answer.

I'm currently shooting a D810. My latest kick is shooting distant eagles and other birds at a local Wildlife Refuge.

I've been contemplating a D7200 for greater reach. However:

D810 = 36 mp
D7100 = 24mp

24x1.5 - 36mp

Someone over at Fred Miranda said you must 24 x 1.5 x 1.5 = 54mp

I just don't get it. Who knows the answer??

Remember, we have to take pixel pitch and pixel density into consideration as well, correct?

Thanks in advance,
Ponz

BebuLamar

It's 54 because it's 24 x (1.5^2) and not 24 x 1.5.

jack schade Loc: La Pine Oregon

I also have 2 D810 bodies, but I am waiting for the D500 to become available for my wildlife shooting.

Jack

ecobin Loc: Paoli, PA

Ponz wrote:

I realize this topic has been beaten to death. But... (show quote)

The crop factor is the ratio of the diagonals (full frame diag to the APS-C diag). However, the equivalent number of pixels is based on the ratio of the areas of the sensors. The ratio of the area of the full frame sensor to that of the APS-C is 2.3. So the 24MP D7200 is equivalent to roughly a 55MP full frame (24mp x 2.3 = 55MP).

rmorrison1116 Loc: Near Valley Forge, Pennsylvania

ecobin wrote:

The crop factor is the ratio of the diagonals (full frame diag to the APS-C diag). However, the equivalent number of pixels is based on the ratio of the areas of the sensors. The ratio of the area of the full frame sensor to that of the APS-C is 2.3. So the 24MP D7200 is equivalent to roughly a 55MP full frame (24mp x 2.3 = 55MP).

This is very confusing to me. I have a 24mpx APS-C camera and a 50.6mpx FF camera. If I crop an image taken with the FF to match an image taken with the APS-C, the resolution of the FF cropped image is still better than the untouched APS-C image. Is this because the individual pixels in the FF sensor are larger than the APS-C sensor or is it just an unfair test?

tramsey Loc: Texas

You have an excellent camera and shooting with an excellent lens; if you are satisfied with you photos why are you trying to muddy the waters??

PixelStan77 Loc: Vermont/Chicago

Perfect Answer

tramsey wrote:

You have an excellent camera and shooting with an excellent lens; if you are satisfied with you photos why are you trying to muddy the waters??

:thumbup:

Ponz

Here's an excellent read:

https://photographylife.com/sensor-crop-factors-and-equivalence

Ponz

orrie smith Loc: Kansas

Ponz wrote:

I realize this topic has been beaten to death. But... (show quote)

which lens are you using and what do you intend to do with the photos? if you are printing extra large prints (16 X 18 or larger), then the pixels will come into play. if you are printing 8 X 10 or smaller, or just posting the photos on social media, the pixels become less important. in my opinion, you may be overthinking the whole pixel battle. take some photos and decide for yourself. if you are going to start shooting birds and wildlife, I would recommend getting a large telephoto lens, such as the Nikon 200-500 or sigma sport model 150-600, I personally prefer the Nikon, but that is your choice. I would suggest that you rent both lenses and see which one works best for you. if you choose the Nikon 200-500, and already have a 1.4 Nikon teleconverter, it will work on the Nikon, not the sigma.
as to the full frame or dx model, your d810 is an excellent camera for shooting both, no need for an extra dx camera such as the d7100 or d7200.

JPL

orrie smith wrote:

which lens are you using and what do you intend to... (show quote)

I agree, there is no need for d7xxx camera when you have a D810. You are better off cropping the photos from D810 or using it in crop mode when taking those bird pics. The D810 has better dynamic range, better autofocus, is better in low light and is in every way a better camera then anything in the D7xxx lineup of cameras. And the difference in pixels in crop mode is not all that much. The other advantages easily make up for it.

Ponz

JPL wrote:

I agree, there is no need for d7xxx camera when you have a D810. You are better off cropping the photos from D810 or using it in crop mode when taking those bird pics. The D810 has better dynamic range, better autofocus, is better in low light and is in every way a better camera then anything in the D7xxx lineup of cameras. And the difference in pixels in crop mode is not all that much. The other advantages easily make up for it.

Even though the math indicates 54mp on subject with a crop sensor vs 36 with the D810? I understand the other factors...

This nest is approximately 328 feet away. The eagles in flight slightly closer. I really had to work the shadow slider in Photoshop to bring out the shadows - but it introduced noise.

BTW - D810 with the Sigma 150-600 Sport

Ponz

SteveR Loc: Michigan

I'm not following your math. However, when shooting a bird at the same distance using a 300mm lens on either a D7200 or a D810, the bird will be projected at the same size by the lens onto each sensor. i.e. A 300mm lens is always a 300mm lens. You might get a field of view of a 450mm lens using the D7200, but the image of the bird will be the same size.

If you're talking about resolution, if the D7200 sensor were made into a full frame sensor, it would be a 55mp sensor. You have to figure what the total area increase would be. So, if you're primarily shooting objects in the center of the lens, stick with the D7200....that is, on a full frame camera, if you're not filling up the entire sensor with your subject.

Ponz

Come again Steve. If my subject matter is small and in the center, the 7200 will perform better?

Ponz

SteveR wrote:

I'm not following your math. However, when shooti... (show quote)

brucewells Loc: Central Kentucky

Ponz wrote:

I've been contemplating a D7200 for greater reach.

I believe if your motive is to get more reach, you're better off looking at glass. I have to believe you'll be disappointed spending money on an APS-C for this purpose. Just my thoughts.

Ponz

brucewells wrote:

I believe if your motive is to get more reach, you're better off looking at glass. I have to believe you'll be disappointed spending money on an APS-C for this purpose. Just my thoughts.

You are correct Bruce. Unfortunately, the Sig 150-600 Sport will have to do unless I hit the lottery.

Ponz