Use the Nikon D7100 or Nikon D780 for long range wildlife shots?

Started 3 months ago | Questions thread
OP Chuck 10108 New Member • Posts: 7
Re: Use the Nikon D7100 or Nikon D780 for long range wildlife shots?

FingerPainter wrote:

Chuck 10108 wrote:

I’m wondering what camera body to use, a crop sensor Nikon D7100 or a full frame Nikon D780, with a Tamron 150-600 F5-6.3 Zoom for long range wildlife shots. This is for shooting sandhill cranes as they return from feeding in the corn fields to bedding down for the night in the marsh. Shots are at a long distance, from 30 meters to 150 meters (due to being limited to shooting from the park’s access roads). The cranes fly in starting about an hour before dusk. In the past we’ve used the zoom, at 600mm full zoom, with the crop sensor Nikon D7100 body. We now also have a full frame Nikon D780.

Since the cranes are so far away, we’d most likely have to crop the D780 photos to get the FOV the same as what we were getting with the D7100. The D7100 is 24.1M pixels, the D780 is 24.5M pixels but if cropped to a DX FOV the image would be 10.9M pixels. So, we’d lose resolution with the D780.

So far so good.

However, the light sensitivity of the D780 is 4x better than the D7100

Where did you get that idea? Unless the D780 is twice as sensitive to light as the D750 (and it isn't - it is nearly the same) then the D780 is only twice as sensitive to light as the D7100.

I rechecked the light sensitivity specs, and it seems the D780 light sensitivity (native ISO up to 51,200) is 8X the D7100 light sensitivity (native ISO up to 6,400).

However, if you crop the D780 image to the size of the D7100 image, you have thrown away more than half the light you captured, thus more than negating the D780's sensitivity advantage.

Yes, but doesn't the D7100 crop sensor only use half the light coming in from the FX lens? So, then isn't the light used for the image the same?

(which could be helpful at dusk especially with the cranes in flight or moving in the marsh).

What’s the recommendation: Use the crop sensor D7100 or the full frame D780?

When shooting distant subjects and desiring maximum detail, you want to put as many pixels on the subject as possible while capturing about the same amount of light on the subject. When you have to use the same lens on both cameras, and both cameras have the same pixel count but one is FX and one is DX, the DX camera will put about 9/4 as many pixels on the subject.

Agreed, but doesn't the number of pixels needed/desired depend on the intended print size? What's a reasonable goal/need for pixels for an 8"x10" or 13"x17" print?

The FX sensor will capture about 9/4 as much light as the DX sensor, but since the subject will only be covered by 4/9 as much of the FX sensor, the amount of light on the subject will be about the same.

Agreed, but don't you still get the advantage of the higher light sensitivity of the D780?

So from this, the D7100 would seem to give a better photo of the subjects in question, until they get so close that you don't have to crop the FX shot and you don't have to use the full 600mm zoom on the DX shot.

Agreed, but where does the benefit of higher light sensitivity start to factor in, and offset the ideal number of pixels (many of the shots will be near dusk)?

Thanks for all your input!

Post (hide subjects) Posted by
(unknown member)
(unknown member)
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow