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Old Dec 14, 2009, 8:33 AM   #1
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Default Why a resized photo is no use in showing camera quality

We get many people here interested in camera/lens/image quality.... aren't we all really as this helps us to get a good image.

To be able to show this quality it can't be done by taking a full image and just resizing for the web as this will hide a myriad of issues including sharpness and noise. It is not until you see a 100% crop can this level of detail be determined. Now I'm not saying a photo must be perfect at 100% as unless you are printing very large it won't be seen, but I just want us to allow other members and guests to get a real idea of what they can expect. All too often we see someone say xyz camera is great, look at this sample, but it is just a reduced shot which tell nothing at all.

To be able to see what I mean I've used a photo which was taken by a friend of mine (we did a swap, I got her son for a minute and she got a Canon 5D.... I was happy to get the 5D back lol). The camera selected the wall behind us to rather than our faces however in the photo reduced for the web this is very hard to tell for sure.

It is not until we see a 100% crop in the 2nd photo that it is possible to tell how far out of focus the faces are. So we go from thinking this has produced an OK but necessarily great photo to it being pretty soft when we see the real deal and probably not the sort of result we would want.

I'm not saying don't post photos at web sizes, as for a lot of things like composition, lighting and many other techniques they are great, as well as sharing some of the simply stunning photographs our members produce. It's only if you are trying to show the quality, please remember to post a 100% crop to let people know the real story (it's always worth showing the reduced and the crop shots the same as I have here so we know what we are looking at).
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Old Dec 14, 2009, 8:39 AM   #2
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Going on from this we have the other side of the coin, where there is a really sharp photo, but again with resizing we can't tell how sharp. In this example it is with a 5D mkII and Canon 24-205, stopped down to f7.1 and this time in the first shot reduced for web it looks really sharp..... but just how sharp is it. A 100% crop gives that information.
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Old Dec 14, 2009, 8:44 AM   #3
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True, but another important piece of information when posting photos is the EXIF data. It helps us identify and diagnose a myriad of other issues, including settings that might have affected noise, sharpness and focus.

So when posting photos, try to preserve the EXIF data.
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Old Dec 14, 2009, 8:47 AM   #4
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Good point, I'm on my work laptop and for the things I do then this is turned off so you won't find them in these images. I do agree though and I get frustrated when looking at something here and can't see the exif.
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Old Dec 14, 2009, 11:58 AM   #5
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Nice post Mark. This is a good thread to keep bookmarked to link back to again.

TCav brought up another good point about preserving the EXIF for the aforementioned reasons.

I think the way you have presented the 2nd picture serves as a good model for others when trying to show off image quality. Presenting the original plus the 100% crop. If members wish to go beyond that, they can do this at a couple different apertures and ISOs. Web-resize images just themselves can be nice to give examples of how the camera handles exposure, white balance, etc.
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Old Dec 14, 2009, 12:00 PM   #6
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Dustin, I've just made it a sticky so it is easier to find for future reference.
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Old Dec 14, 2009, 1:42 PM   #7
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Default Interesting point!

While we are talking about 100% crop I would appreciate a precise answer of what such a 100% crop really consists of, or what it is, and how one goes about producing one. How are we going to measure a 100% crop when preparing such an example to Post / show in our forum?

Just to be sure that everybody is thinking the same 100%-way. When I think of a 100% crop I get several different pictures in my mind...


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Old Dec 14, 2009, 2:12 PM   #8
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the name is actually not quite right. 100% crop would mean you didn't crop anything and it would be the full image. however, 100% crop as it is used means a crop out of 100% view.

Basically it's this.

1)open picture in image-editing program (i.e. photoshop)
2) now change the viewing size to 100% (or click actual pixels)
3)now just crop what part you want leaving the resolution or ppi box blank
4)u can also use the marquee tool and then specify the size you want, then copy and paste to a new document.
5)don't do any further processing

voila- 100% crop
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Old Dec 31, 2009, 9:05 PM   #9
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Quote:
Originally Posted by Mark1616 View Post
It is not until we see a 100% crop in the 2nd photo that it is possible to tell how far out of focus the faces are. So we go from thinking this has produced an OK but necessarily great photo to it being pretty soft when we see the real deal and probably not the sort of result we would want.

I'm not saying don't post photos at web sizes, as for a lot of things like composition, lighting and many other techniques they are great, as well as sharing some of the simply stunning photographs our members produce. It's only if you are trying to show the quality, please remember to post a 100% crop to let people know the real story (it's always worth showing the reduced and the crop shots the same as I have here so we know what we are looking at).
Err, nothing is in focus...

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Old Dec 31, 2009, 9:09 PM   #10
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Quote:
Originally Posted by [LEFT
Chato[/LEFT];1033646]Err, nothing is in focus...

Dave
Which part are you referring to?
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