Home · Register · Search · View Winners · Software · Hosting · Software · Join Upload & Sell

Moderated by: Fred Miranda
Username   Password

  New fredmiranda.com Mobile Site
  New Feature: SMS Notification alert
  New Feature: Buy & Sell Watchlist
  

FM Forums | Canon Forum | Join Upload & Sell

1
       2       3       end
  

Archive 2013 · A simple test: full frame versus crop
  
 
Harry.C
Offline
• •
Upload & Sell: Off
p.1 #1 · p.1 #1 · A simple test: full frame versus crop


On another forum yesterday I got into a discussion with someone regarding full frame versus crop sensors. On the subject of the extra reach provided by a crop sensor they had this to say:
you could crop a full‐frame image and achieve exactly the same thing

This is not the first time I've heard this, and since I'm a curious person and had the gear to test this, I set up a simple test. Canon 1DX versus 7D, on the following subject:






Same crop of final image, same settings, lens did not move, here are the results.












At the very least I think this demonstrates that cropping a full-frame image will not yield the same results as the image from a crop sensor. I'm not sure what else you can conclude from my little test, but I thought I'd post it here for those that were curious.

If someone has a 5D mk III and a crop body I'd love to see a similar test to see how much the extra pixels from the 5D change the situation.

Cheers,
Harry C

[edit]
The forum is resizing both my images to be the same size which defeats the point a bit. If the difference isn't that clear you can access the un-resized images here:

1DX

7D



Jan 14, 2013 at 01:48 PM
gdanmitchell
Online
• • • • •
Upload & Sell: On
p.1 #2 · p.1 #2 · A simple test: full frame versus crop


If you shoot the same lens/aperture on a cropped sensor body and a full frame body and then crop the FF image so that you only use the APS-C size center section, what happens is actually pretty simple to understand:

1. If the two cameras have the same number of pixels in the section used in the crop, the image quality should be the same, assuming that the cameras otherwise perform equally.

2. If the APS-C size section from the cropped full frame image has fewer pixels than the cropped sensor image, you could be somewhat more limited by the lower pixel resolution.

(3. I suppose we can imagine a comparison between a very high photo site density full frame camera and a very low density cropped sensor camera, in which the FF body has the higher image quality potential.)

Looked at in isolation, what happens in these cases is pretty simple. However, there is larger context for most people trying to act on this, namely questions of whether or not other aspects of full frame and cropped sensor performance better meet their overall needs, and just how significant the difference in resolution is in their photography. Such decisions are rarely made on the basis of a single parameter.

Dan

(slightly edited)

Edited on Jan 14, 2013 at 05:14 PM · View previous versions



Jan 14, 2013 at 02:00 PM
Scott Stoness
Offline
• • • • •
Upload & Sell: On
p.1 #3 · p.1 #3 · A simple test: full frame versus crop


I have done this similar test (but not as controlled as you) and concluded the same with 5diii. That 7d has more resolution than 5diii cropped at the same distance.

There are a number of factors that cause this:
1) 7d puts more pixels on the same area - so more resolution.
2) The 5diii sensor is better because the pixels are bigger and it gathers photons better
3) The 7d only uses 1/1.6 of the lens, so if the lens resolution is the limiting factor, you won't get 60% better

My conclusion is that the 7d gets about 40% more effective reach than 5dii, rather than 60% with a good lens.

However, the 7d does 1.5 stops less in ISO ability so 5diii has better colors, less noise, better focus, but less fps, so both cameras complement each other well. 5diii with 1.4x is closing in on 7d.

Scott

Edited on Jan 14, 2013 at 02:17 PM · View previous versions



Jan 14, 2013 at 02:13 PM
Vincentwong
Offline

Upload & Sell: Off
p.1 #4 · p.1 #4 · A simple test: full frame versus crop


Very interesting Harry. Most wildlife photographer who opt for the crop sensor camera are because of the reach. How would you translate that by shooting from the same distance on your subject and later crop the FF shot to size.

Vincent



Jan 14, 2013 at 02:15 PM
ggreene
Online
• • • •
Upload & Sell: Off
p.1 #5 · p.1 #5 · A simple test: full frame versus crop


Pixel density is solely responsible for the perceived reach you get. Highly dependent on ISO settings though. Each camera is going to have a threshold where better ISO overtakes pixel density.

I just switched from a 1D4 (~27MP FF) to the 1DX (18MP FF) and the cutoff in my testing was around 2000 ISO.

Edited on Jan 14, 2013 at 02:51 PM · View previous versions



Jan 14, 2013 at 02:43 PM
Photon
Offline
• • • • • •
Upload & Sell: On
p.1 #6 · p.1 #6 · A simple test: full frame versus crop


gdanmitchell wrote:
...
(3. I suppose we can imagine a comparison between a very high photo site density full frame camera and a very low density cropped sensor camera, in which the FF body has the higher image quality potential.)
...
Dan

Easily: imagine an APS-C sized section from 5D Mk III (~8.6 MP) vs a D30 (3.15 MP).
Think of the years of friendly discussions and occasional misunderstandings that have resulted from the stopgap decision of the camera manufacturers to use existing 35mm film lenses on their early DSLRs, all of which had smaller sensors. Before that, lenses were generally designed for a particular format (well, except in the world of large format sheet film), so we didn't have to think about the "crop factor" of miniature cameras (35 mm) or the film grain clusters per duck!

I do think the "reach" argument is perfectly valid, so long as all the factors involved in making the photo are taken into account, which of course is exactly what Dan said so clearly. I'm just a ramblin' guy...



Jan 14, 2013 at 02:44 PM
lowa2
Offline
• • • •
Upload & Sell: On
p.1 #7 · p.1 #7 · A simple test: full frame versus crop


Canadian Tire money Nice little experiment Harry.

Thanks for sharing it.



Jan 14, 2013 at 03:02 PM
Yohan Pamudji
Offline
• • •
Upload & Sell: On
p.1 #8 · p.1 #8 · A simple test: full frame versus crop


The 1DX has less pixels than the 7D to begin with, then you cropped on top of that. Did you really expect any other result in this test? The adage that "you can crop a FF and get the same result" only applies when the resulting crop from FF has the same or more pixels than the APS-C.

In fact around here I think the consensus is that when you're focal length limited (i.e. you're using the longest lens you have, can't get any closer to the subject, and still aren't able to get the subject big enough in the frame, for instance with wildlife) it's better to use a high resolution crop sensor than a FF sensor for this very reason.



Jan 14, 2013 at 03:44 PM
Harry.C
Offline
• •
Upload & Sell: Off
p.1 #9 · p.1 #9 · A simple test: full frame versus crop


Yohan Pamudji wrote:
The 1DX has less pixels than the 7D to begin with, then you cropped on top of that. Did you really expect any other result in this test?

I never expected any other result, and I think I was quite clear in my OP about the nature of this test. There are a lot of people that think the extra reach of a crop sensor is irrelevant/not applicable when talking about current camera systems. This post hopefully shows those people that there is still a very visible difference.

Cheers,
Harry C



Jan 14, 2013 at 03:54 PM
robbymack
Offline
• •
Upload & Sell: Off
p.1 #10 · p.1 #10 · A simple test: full frame versus crop


so really all you have proven here is that in general modern crop sensors puts more pixels on target? Thats not not surprising, hence the reason APS-C is a good option for any situation you find yourself FL limited.


Jan 14, 2013 at 03:58 PM
 

Search in Used Dept. 



Mescalamba
Offline
• • • •
Upload & Sell: Off
p.1 #11 · p.1 #11 · A simple test: full frame versus crop


robbymack wrote:
so really all you have proven here is that in general modern crop sensors puts more pixels on target? Thats not not surprising, hence the reason APS-C is a good option for any situation you find yourself FL limited.


At least in Canon camp its like this. You would need 28-30 mpix camera to reach same amount of detail from crop as you do with 7D. Which currently can be done only with Nikon.



Jan 14, 2013 at 04:01 PM
Mike Sowsun
Offline
• •
Upload & Sell: Off
p.1 #12 · p.1 #12 · A simple test: full frame versus crop


My experiences are different. With my 7D and 5D Mk II I see little difference even with the 5D Mk II cropped to match the 7D.














Jan 14, 2013 at 04:05 PM
howard
Online
• • •
Upload & Sell: Off
p.1 #13 · p.1 #13 · A simple test: full frame versus crop


When they say "you could crop a full‐frame image and achieve exactly the same thing", it is implied that the two cameras had the same pixel density. Nikon has some cameras that allows you to "choose the format", in which case it exactly achieves this (cropping off the outer areas of the image).

When they have different pixel density, then the resolution is determined by .. well, the pixel density of each sensor.

Really, is is a very simple concept (but thanks for the test to demonstrate).

(But don't let the "equivalence" folks hear about it).



Jan 14, 2013 at 04:20 PM
Harry.C
Offline
• •
Upload & Sell: Off
p.1 #14 · p.1 #14 · A simple test: full frame versus crop


Mike Sowsun wrote:
My experiences are different. With my 7D and 5D Mk II I see little difference even with the 5D Mk II cropped to match the 7D.

In your test Mike you were quite close to the subject (assuming your first two pics are uncropped, full images). In these cases I would expect results like what you've obtained, although it is useful to see it regardless and you have certainly demonstrated that for subjects that fill a large part of the frame you will see almost no difference if you crop a full frame image to match the crop factor of a crop sensor.

There is obviously a point somewhere between the distance you have shot from your subject and the distance I have where the line blurs (literally) and the image quality goes from acceptable if it's from a crop but unacceptable if it's from a full frame.

Thanks for the test results, and for using Canadian Tire money.

Cheers,
Harry C




Jan 14, 2013 at 04:20 PM
Harry.C
Offline
• •
Upload & Sell: Off
p.1 #15 · p.1 #15 · A simple test: full frame versus crop


howard wrote:
Really, is is a very simple concept (but thanks for the test to demonstrate).


I want to be really clear since some people (not you) are getting negative in their comments...all I posted was a quick test to show you can't always crop a full frame image to achieve the same results as that obtained from a crop sensor. This has always been obvious to me, but it isn't for everyone.

Cheers,
Harry



Jan 14, 2013 at 04:22 PM
thedutt
Online
• • • •
Upload & Sell: Off
p.1 #16 · p.1 #16 · A simple test: full frame versus crop


Thanks for sharing the test results, abet it would be more helpful to see how the various factors play in, e.g. ISO, subject distance etc. For the type of wildlife that I shoot, I like mikes analogy a bit better, if the subject is taking up only a very small %age of the frame, I am yet to take a shot that I like, on the other hand it is not unusual to crop about 20-50% of frame away.

Also Scott had shared a thread when he had acquired his 5DIII, I cannot find the link but that was quite useful to see how the densest of canon sensors (7D) did against the latest FF ( 5DIII )



Jan 14, 2013 at 04:31 PM
howard
Online
• • •
Upload & Sell: Off
p.1 #17 · p.1 #17 · A simple test: full frame versus crop


Harry.C wrote:
I want to be really clear since some people (not you) are getting negative in their comments...all I posted was a quick test to show you can't always crop a full frame image to achieve the same results as that obtained from a crop sensor. This has always been obvious to me, but it isn't for everyone.

Cheers,
Harry


I did not mean to sound negative (did I?). Your point is well taken and I said thank you for the test.

Edit: well, you said "not you", anyways, cheers.

BTW, I do like Nikon's concept of in-camera cropping, provided that the sensor has enough resolution. If Canon can come up with a 40~48MP FF camera with good AF and ISO performance (which is equivalent to 25-30MP on APS-C), that would be wonderful.



Jan 14, 2013 at 04:35 PM
buggz2k
Offline
• • •
Upload & Sell: Off
p.1 #18 · p.1 #18 · A simple test: full frame versus crop


I am uncertain about EXACTLY the same thing.
However, I DO know from direct experience, that I can crop my 5DMkII RAW files to an incredible amount, and STILL achieve great results.
No, I did not read the entire thread...

Harry.C wrote:
On another forum yesterday I got into a discussion with someone regarding full frame versus crop sensors. On the subject of the extra reach provided by a crop sensor they had this to say:




Jan 14, 2013 at 04:42 PM
galenapass
Offline
• • • •
Upload & Sell: On
p.1 #19 · p.1 #19 · A simple test: full frame versus crop


Harry.C wrote:
I want to be really clear since some people (not you) are getting negative in their comments...all I posted was a quick test to show you can't always crop a full frame image to achieve the same results as that obtained from a crop sensor. This has always been obvious to me, but it isn't for everyone.

Cheers,
Harry



Good to see data occasionally. Too much opinion on this forum and not enough actual data, IMO. Thanks Harry.



Jan 14, 2013 at 04:43 PM
Mike Sowsun
Offline
• •
Upload & Sell: Off
p.1 #20 · p.1 #20 · A simple test: full frame versus crop


Harry.C wrote:
In your test Mike you were quite close to the subject (assuming your first two pics are uncropped, full images). In these cases I would expect results like what you've obtained, although it is useful to see it regardless and you have certainly demonstrated that for subjects that fill a large part of the frame you will see almost no difference if you crop a full frame image to match the crop factor of a crop sensor.

There is obviously a point somewhere between the distance you have shot from your subject and the distance I have where the line blurs
...Show more

Yes, my first test was only about 8' away.

These are from over 100' away and I still don't see a large difference. Yes the 7D is slightly better but I still do not see a huge difference as your test suggests. Is it simply because the 5D Mk II has more MP than the 1Dx?










Jan 14, 2013 at 04:52 PM
1
       2       3       end




FM Forums | Canon Forum | Join Upload & Sell

1
       2       3       end
    
 

You are not logged in. Login or Register

Username   Password    Reset password