Post your 100% crops

[Rebel without a cause]

How can you tell when a photo will be sharp enough for enlargements such as 16x20? Please post your 100% crops so I have a better idea of what to look for when making a judgement on the sharpness on my photos.

[Radtech1]

You don't really need that. If it looks good as a 4x5 in your hand, it will look good as a 16x20 on the wall. Keep in mind that the viewing distance for the larger print is further away, and, as such, any lack of "tack sharpness" will be less evident.

Rad

[eddarr]

That's way to vague. Different types of pictures will need different amounts of sharpening. Any dSLR will have no problem printing to 16x20.

Check out this sharpening sticky (http://photography-on-the.net/forum/showthread.php?t=466333). And Tim's printing faqs (http://photography-on-the.net/forum/showthread.php?p=3740438).

[cdifoto]

If it's in focus and not killed by camera shake, it's sharp enough.

[sumptimwong]

This is a good question, thanks for posting. The link to "Tim's printing faqs" cites 250-300 PPI (pixels per inch) as a good resolution for prints which will be examined closely, or about 75 PPI for large prints (up to 30") which will be viewed from some distance. However, this does not account for the original sharpness of the image, which accounts for the lens, body, ISO, among other things.

I too would like to see examples for 100% crops which were good up to "Size X by X" when printed.

[Woolburr]

What do 100% crops have to do with prints? And here is a 100% crop....jump on it. The print is stellar at 16x20.

[eddarr]

A 100% crop just isn't going to show you if a print will look good or not. If everything is OK with the original capture you will get a print at least as good as your lens is capable. Meaning no camera shake, motion blur etc. Again any decent lens on a reasonable camera will produce prints larger than most people will ever print as long as you do your job.

[chauncey]

A dissenting opinion.

That 100% crop will give you a quick check to determine if you have a keeper or have some sort of a problem with the camera/lens or user error.

An example is that I couln't figure out why my AF was not spot on.
Some testing shows this and it, in my mind, confirmed the problem.
The "X" was the center point focus target with my 5D/70-200 f/4.0 ISL
.

[kevin_c]

What do 100% crops have to do with prints? And here is a 100% crop....jump on it. The print is stellar at 16x20.

Nice shot - Could do with a levels adjustment tho' IMO ;)

Might look good in B&W...?

:lol::lol:

[eddarr]

Chauncey the point is that we can always find something wrong with an image. Testing a camera or lens to verify that it is focusing wrong is not the same thing as taking a landscape picture. There may be times (like macro) where an 1/8" off in focus makes a difference but for 90% of the work we do it's just not that big.

But take that same camera/lens out into your front yard, put it on a tripod, set it to f/11, manual focus and use a cable release. I guarantee you that it will make an acceptable print up to 20x30 without resampling or any other major PP.

[chauncey]

Ed, you are absolutly correct that at f/11 the front focusing would not be visible.
But then, I'm an anal retentive kinda guy and want my stuff to function properly.

[eddarr]

Agreed, that is an expensive lens and it should work properly. That is what a 100% crop will tell you, if the lens or camera is working properly. Do it once and then forget about it.

[Radtech1]

That 100% crop will give you a quick check to determine if you have a keeper or have some sort of a problem with the camera/lens or user error.


Unless I misunderstood the OP, I believe he is NOT trying to use the 100% to filter keepers/non-keepers. Rather, I believe he wants to use the 100% crop to determine enlargeabity of a shot already deemed a keeper.

That is where the 100% is not too valuable, in that it does not take into account viewing distance. That is why I said "If it looks good as a 4x5 in your hand, it will look good as a 16x20 on the wall."

Rad

[Rebel without a cause]

Yes Radtech, that's what I was asking. Thanks for the feedback everyone!

[JeffreyG]

A dissenting opinion.

That 100% crop will give you a quick check to determine if you have a keeper or have some sort of a problem with the camera/lens or user error.

An example is that I couln't figure out why my AF was not spot on.
Some testing shows this and it, in my mind, confirmed the problem.
The "X" was the center point focus target with my 5D/70-200 f/4.0 ISL
.


That entire image is full of high contrast. There is no way to know what the AF mechanism decided to lock onto. It may simply have picked some bit of text forward of the big X.

People don't seem to know this, but the AF system is larger than the little boxes in the viewfinder, and any high contrast item that the true AF crosses is fair game for the system to lock on to.

One other problem I have with most focus testing is that people tend to do it at near macro ranges. Like the text shot, how often do you use the lens at that short range? It's a relevent question as some lenses become innaccurate right up close to the MFD but will perform normally from a few meters to infinity.

The EF 70-200/4 has a reputation for innaccurate focus near the MFD BTW.

[chauncey]

both my 5D and Ds MkII are going back to canon for warrenty work, per their request.