What to expect from 100% crops?

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RobertLynn
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p.1 #1 · What to expect from 100% crops?

I've been reading for too long (I think so) about everyone saying "look at 100% crops of the picture" to judge sharpness and blah blah blah.

If I get a bad or negative idea in my hdea, I cannot get it out, without a jackhammer.

Looking over my shots of my 24-70 that I KNOW is sharp, I keep looking thinking...these 100% crops look like ass.

Same with my 70-200, I did some tests and I'm like, well the lens isn't front focusing (by no means precise tests, but little pop quizzes if you will), but it sure doesn't seem right.

So in reality, what can you expect from 100% crops?

70-200 2.8 200mm

24-70 16 50mm ISO800

70-200 2.8

24-70 2.8 I forget the focal length

I'm probably thinking too much about it, but I've had some recent missed focuses (don't see it being motion blur at 1/2000 of a second) and some other issues, that make me wonder, have I just been lucky with the photos I get, that are sharp? Hopefully it's just thinking too much, but like I said, once a bad idea is in my stupid head, it doesn't want to come out.

Later I think I'll do some shots from a tripod, and and multiple focal lengths, blah blah.

Oct 11, 2008 at 09:07 PM

ChrisDM
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p.1 #2 · What to expect from 100% crops?

Forget 100% crops, look at images at your largest regular output size. That's the only measure that's relevant to you.

Chris M
www.imagineimagery.com

Oct 11, 2008 at 09:11 PM

RobertLynn
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p.1 #3 · What to expect from 100% crops?

ChrisDM wrote:
Forget 100% crops, look at images at your largest regular output size. That's the only measure that's relevant to you.

Chris M
www.imagineimagery.com

Strangely enough, i've told myself that about 73 times since I've made the post, and at least 276000 times before that today.

I agree 100%, who cares what it looks like at 20X30, if I'll never print it.

I'm almost 100% positive, I don't have any issues what-so-ever in regards to equipment, however (this has to have come from playing music for too many years and tweaking every little thing), I have to wonder...if there is an issue?

Oct 11, 2008 at 09:18 PM

AGeoJO
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p.1 #4 · What to expect from 100% crops?

Well, if you insist, this is a 100% crop of an image taken with a sharp 70-200mm f/2.8L IS that I just sold to Ryan Hough. The aperture used was f/3.5. The FF image is also enclosed.

Exif information
Model	Canon EOS-1Ds Mark II
Date	2008:10:11 14:13:51
Original date	2006:05:21 12:27:16
Exposure time	1/1250 sec
Focal length	100mm
Focal number	f/3.5
ISO speed	400 ISO
Exposure compensation	0.0

Exif information
Model	Canon EOS-1Ds Mark II
Date	2008:10:11 10:55:00
Original date	2006:05:21 12:27:16
Exposure time	1/1250 sec
Focal length	100mm
Focal number	f/3.5
ISO speed	400 ISO
Exposure compensation	0.0

Edited on Oct 11, 2008 at 09:22 PM · View previous versions

Oct 11, 2008 at 09:19 PM

jcolwell
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p.1 #5 · What to expect from 100% crops?

The focal length for the blue palet was 51mm. Courtesy of Opanda IExif 2.

Oct 11, 2008 at 09:22 PM

RobertLynn
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p.1 #6 · What to expect from 100% crops?

Thanks J, I had looked at the exif, and when I was typing, I forgot it, and didn't feel like going back.

Ag, how much processing did you do to that image? Mine were straight out of the camera, and not with a 1D series

Oct 11, 2008 at 09:32 PM

RobertLynn
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p.1 #7 · What to expect from 100% crops?

Here's 100% from 24-70

here's 100% from 70-200

Oct 11, 2008 at 09:39 PM

Mike Abbott
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p.1 #8 · What to expect from 100% crops?

AGeoJO - maybe I'm missing something here, but I can't see how the top image can be a 100% crop, if the bottom image is full frame from a 1Ds MkII - with a 4,992 pixel wide frame.

Oct 11, 2008 at 09:40 PM

RobertLynn
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p.1 #9 · What to expect from 100% crops?

Take 4992 and divide it by 800, that gets you 6.24 take 533 and multiply it by 6.24, and that gives you 3325.92.

The 1dsMk2 I believe has files that are within 10pixels either way of that.

So the top image is the 100% crop, and the bottom image is the full sized image, resized to the smaller size.

Oct 11, 2008 at 09:44 PM

AGeoJO
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p.1 #10 · What to expect from 100% crops?

Robert,
I applied a fair amount of sharpening, not overly but still not a fair comparison. If straight from the camera then we are comparing the strength of the AA filter and of course, the larger sensor size of the FF camera plays a significant role in the apparent difference.

Mike,
I used LR 2 to give me a 1:1 ratio and that's what I cropped the image onto. I exported that file as jpg medium and sharpened for web presentation. I set the quality to about 75% to minimze the jpg artefact but still within the allowable size limit for FM. I took it as a compliment that you didn't buy that it was a 100% crop

.

Edited on Oct 11, 2008 at 10:47 PM · View previous versions

Oct 11, 2008 at 09:48 PM

ChrisDM
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p.1 #11 · What to expect from 100% crops?

RobertLynn wrote:
ChrisDM wrote:
Forget 100% crops, look at images at your largest regular output size. That's the only measure that's relevant to you.

Chris M
www.imagineimagery.com

Strangely enough, i've told myself that about 73 times since I've made the post, and at least 276000 times before that today.

I agree 100%, who cares what it looks like at 20X30, if I'll never print it.

I'm almost 100% positive, I don't have any issues what-so-ever in regards to equipment, however (this has to have come from playing music for too many years and tweaking every little thing), I have to wonder...if there is an issue?

Hanging out in equipment-based forums, you'll likely become biased by "equipment based" photographers, gearheads etc... For many there's really no practical application to the quest for microscope level sharpness (they don't print 24x36 etc), rather the quest for this ultimate sharpness is simply a driven hobby. There's nothing wrong with that, except these types of discussions deviate too far from the practical. For me, I shoot lots of different stuff. I shoot weddings professionally and primarily use a 24-70 and a 70-200 2.8. I've never examined microscope sharpness, corner sharpness etc on these lenses, because for what I use them for it simply doesn't make a difference. But I also sell large format landscape prints in a local gallery. So for my landscape lenses, I have no use for fast, heavy glass. But I do seek corner sharp, lightweight glass to shoot this work with. So I simply like to point out the utility of considering the application when considering your lenses and their relative performance. And the next time you hear someone complaining about a portrait lens's lack of corner shaprness wide open, think to yourself, "So what?"

Chris M
www.imagineimagery.com

Oct 11, 2008 at 09:55 PM

RobertLynn
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p.1 #12 · What to expect from 100% crops?

Chris, I agree with and appreciate everything you're saying.

However, when viewing photos that other people take, even with the EXACT same gear, I always am like...wtf is the problem here? I've been told, and I believe that my lenses are sharp, however at the same time, the more I look at the results others are getting, and the results I'm getting, I think that I've got an issue.

Oct 11, 2008 at 10:14 PM

ghozer
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p.1 #13 · What to expect from 100% crops?

Pixel peeping is arguably the worst thing that ever happened to photography. And, I love doing it.

Oct 11, 2008 at 10:42 PM

RobertLynn
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p.1 #14 · What to expect from 100% crops?

ghozer wrote:
Pixel peeping is arguably the worst thing that ever happened to photography. And, I love doing it.

It has me questioning 2 cameras and 2 lenses, and I'm sure if I added crops from my other 2, I'd be questioning them as well.

I hate it!

Oct 11, 2008 at 10:54 PM

RobertLynn
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p.1 #15 · What to expect from 100% crops?

Tomorrow, when the light is good, I think I'm going to go outside with the tripod, and both lenses. Shoot them both at 2.8, 4, 5.6, 8, 11, and 16, and at 24 28 35 50 70mm on the 24-70, and the same marked ranges on the 70-200 to see what happens.

If I don't, I'm going to drive myself nuts...and if I'm already nuts, I'm going to drive myself the rest of the way to crazy.

Oct 11, 2008 at 11:56 PM

wilt
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p.1 #16 · What to expect from 100% crops?

100% crops as an evaluation is an absurdity, and here is why:

You are mapping 1 pixel on image to 1 pixel on computer monitor, and that is a HUGE image to evaluate from a mere 18-24" viewing distance!

I just did a test on my home system to illustrate. I drew a line across a feature in the photo, it was physically 27cm long on my monitor at 100%. I stored the photo, then I looked at the full width of the photo vs. the length of the line...it was 23.6% of the total frame width. In other words, the 27cm line at 100% meant that I was viewing effectively a 45" wide photo from 18-24" away, and no one would be doing that! It was the same as viewing a 50x enlargement from my APS-C frame, from 18-24" away.

Oct 12, 2008 at 12:26 AM

Gary Petersen
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p.1 #17 · What to expect from 100% crops?

Here's the whole photo. 200mm at f2.8

Oct 12, 2008 at 12:54 AM

RobertLynn
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p.1 #18 · What to expect from 100% crops?

Gary, what do you think, do my 100% crops seem on par with what they should be? I mean, you've seen the pictures my 24-70 and 70-200 have produced. I'm figuring your 100% crop was your new 1dmk3, so I'm thinking yours would be much better right off of the bat, but I believe you owned a crop first?

Oct 12, 2008 at 12:59 AM

Gary Petersen
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p.1 #19 · What to expect from 100% crops?

From a cropper.

Yours look good enough. Hard to me to really tell without the whole file up in photoshop.

Oct 12, 2008 at 01:13 AM

RobertLynn
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p.1 #20 · What to expect from 100% crops?

Gary, thanks. I understand what you mean about the full file. However, I don't know any site that I can load my full file size on. Photobucket is pretty much a waste.

Oct 12, 2008 at 01:38 AM

AJSJones
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p.1 #21 · What to expect from 100% crops?

AGeoJO wrote:

Mike,
I used LR 2 to give me a 1:1 ratio and that's what I cropped the image onto. I exported that file as jpg medium and sharpened for web presentation. I set the quality to about 75% to minimze the jpg artefact but still within the allowable size limit for FM. I took it as a compliment that you didn't buy that it was a 100% crop

.

Sorry, I still confused!
The vertical distance from the eye to the centre of the lips is 113 pixels in the "whole image" but 264 pixels in the "100% crop" That's only a 2.3 fold enlargement. If the whole image resized as posted is 530 pixels high, then the crop at 530 pixels high should be a 6.3x enlargement if the "true" size is 3328.

What am I missing - a 100% crop is pixel for pixel the same as the original size, without any resizing applied, just a portion of the original, right?

Edited on Oct 12, 2008 at 02:01 AM · View previous versions

Oct 12, 2008 at 01:40 AM

RobertLynn
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p.1 #22 · What to expect from 100% crops?

It was my understanding that a 100% crop was ANY portion of the image or the whole image at the native resolution.

So say my image is 800x600 (hypothectically this is what the camera makes) and I want to show you the 100% crop of say the center, I could "crop" the center 80X60 pixels, or 80X80, or 40X40, and they are 100% crops of the actual pixels.

It'd the similar to going to photoshop or DPP and clicking ctual pixels or 100% view.

Oct 12, 2008 at 01:44 AM

omarlyn
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p.1 #23 · What to expect from 100% crops?

RobertLynn wrote:
...these 100% crops look like ass.

Robert, allow me to add this from my perpective: Whenever I have done a 'sharpness test' or 'IQ test' I have found fault with my lenses/cameras every single time. However, when I look at my regular everyday images, I never see any lens or camera faults (only the occasional user error). This includes images that I have printed upto 16x20 (I have only rarely made anything bigger). I only seem to notice back/front focusing, softness, etc, etc, when I've 'pre-concluded' that it's there....but those faults never seems to show up when I'm out just using the equipment taking regular/normal photos. Hope that helps.

Omar

Oct 12, 2008 at 02:07 AM

AGeoJO
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p.1 #24 · What to expect from 100% crops?

AJSJones wrote:
Sorry, I still confused!
The vertical distance from the eye to the centre of the lips is 113 pixels in the "whole image" but 264 pixels in the "100% crop" That's only a 2.3 fold enlargement. If the whole image resized as posted is 530 pixels high, then the crop at 530 pixels high should be a 6.3x enlargement if the "true" size is 3328.

What am I missing - a 100% crop is pixel for pixel the same as the original size, without any resizing applied, just a portion of the original, right?

Since Photoshop is more widely used than Lightroom, let me use PS in explaining how I derive my 100% crops. At least, this is my understanding of 100% crops - If you open a full size image, tif or jpg, using PS, regardless of your camera resoluaiton/pixel size (and we are not even going there), take a look at the "Navigator" folder. Under the image itself, there is a display indicating the size displayed and right next to it, there is a slider. Using the slider, I adjusted the display to show 100%. That is the way I choose my 100% crop. On the image itself, there is a red area showing where the crop is located relative to the total image. You can move that area around to choose what area you want to show as 100%. From there you cropped accordingly, resize the crop to whatever size you want to disply, choose your jpg compression, sharpen and what not. In LR, you just click the 1:1 button or you can choos 1:2 or 2:1 and other ratios.

Hope this helps. BTW, I am open to discuss this and if my method of making 100% crop is not correct, then by all means, please let me know.

Oct 12, 2008 at 03:14 AM

RobertLynn
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p.1 #25 · What to expect from 100% crops?

Ageo, if you resize the crop, then it's no longer a 100% crop. The crops I posted are actual pixels of the images, without any resizing.

If I resize them, they get much, much sharper.

Oct 12, 2008 at 03:33 AM


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