Can You Tell It Is Sharp?

[BoySpot]

As I read through various threads about people getting new lenses, they often post a shot with the new lens and get comments back about how razor sharp they are. Given that these images are downsized to go on the web, is it really possible to judge the sharpness from these shots. I assume 100% crops are a more realistic indication of what you can resolve in the image or am I misjudging this.

The advice of the knowledgeable will be welcome.

Thanks

[GyRob]

i think small images will look sharp even when there not ,yes 100% crop is far more realistic.
Rob.

[schmoelzel]

Yes, you are right about resizing adding sharpness to a shot; but try and resize a very soft or OOF focus shot and you will be able to tell that it isn't 'right', even resized for the web. I have been asked for 100% crops from some of my posts (which I don't mind doing) and each time the viewer has been equally impressed with the detail as with the resized version.

(don't know if I am one of the knowledgable though......still learning myself!! :D)

[CyberPet]

Problem is if you are a pixel peeper you look at stuff in 100% in Photoshop, but when you look at a print from a 8 megapixel camera in 8 x 10 paper, it's a whole different thing. You don't oogle closely on the print to see the picture, you stand back a bit, to take it all in. So even an unsharp image looks good in print, but blown up in 100% in Photoshop any lens can look unsharp.

I'm just a bit of a pixel peeper.... so I try to take all in, both how it looks like in 100% in Photoshop, but also look on the screen how it will look like as a print or posted on the web.

[Tom W]

I know I'm basically repeating what's been said, but the 100% crop is a good way to test sharpness, and compare lenses. But it is not the best indicator of how the image will look in the final print. Yes, if the final print is a double-page spread, it is going to need to have very high resolution and that resolution will need to stand the scrutiny of the 100% crop. However, for more ordinary 8X10 and 11X14 inch prints, the necessary 100% sharpness is not going to be so necessary. A little softness at that magnification will not be visible in the print.

[Andy_T]

Tom, I agree with you.

Also, 100% sharpness might not really be what you are looking for for some applications, e.g. portraits.

Still, it's always easier to start with an image that is tack sharp out of the camera with the lens used wide open:D

Take a look at this thread: Things to check right after you bring your camera home (http://photography-on-the.net/forum/showthread.php?t=58493&highlight=test)

Best regards,
Andy

[BoySpot]

I guess my original query was really not an issue about sharpening techniques. It was a question as to whether there is any validity in some of the comments I see on the forum about how sharp someone's newest lens is. They put up a full image shot (resized for the web) and then get a number of comments stating how the lens is sharp as a tack. I thought this wasn't a realistic test but wanted to find out whether I was wrong in thinking this. Any thoughts?

[Tom W]

I guess my original query was really not an issue about sharpening techniques. It was a question as to whether there is any validity in some of the comments I see on the forum about how sharp someone's newest lens is. They put up a full image shot (resized for the web) and then get a number of comments stating how the lens is sharp as a tack. I thought this wasn't a realistic test but wanted to find out whether I was wrong in thinking this. Any thoughts?

I guess to answer the question more directly, I'd say that reduced shots are not going to lend strong evidence to someone's judgement of a lens being "sharp as a tack". It will indicate whether the lens is sharp enough to produce good images at the size you see them on your screen, though. You can't see as much detail on an 800 pixel wide image as you can on the 100% crop, but the 100% crop is not necessarily realistic for real-world image output.

Or, to make a long story short, if someone claims that a lens is tack sharp, I want to see 100%, or at least 50% (which is probably a more realistic view anyway).

[BoySpot]

Tom,

Thanks for that. What you say ties in with what I was thinking. I just wanted to make sure I was not too far off beam when I thought that some of the comments were premature.

Cheers

[PhotosGuy]

In some (maybe all) of those cases, I think they just want to get a pat on the back for spending all their lunch money on a new "L"! :D:D

[BoySpot]

LOL!