View Full Version : Advice on Soft Corners

A Brown
17-Mar-2005, 18:29
I am photographing my wife's artwork for archival and future reproduction purposes. Can someone please give me advice on making sure the image is focused from corner to corner? I am composing and then focusing with a loupe but am finding some of the corners to be occassionally soft and somewhat out of focus.

Any help and/or advice would be greatly appreciated.

David A. Goldfarb
17-Mar-2005, 18:35
Assuming you've got everything aligned and parallel, maybe you need to stop down more or use a lens with more coverage. What lens are you using, and how large is the work?

Ralph Barker
18-Mar-2005, 09:07
As photographers get older, many develop soft corners. Some even develop soft middles. While a good exercise routine can minimize this, it's best started at an early age. ;-)

As David suggested, it sound like your lens doesn't have sufficient coverage, or you may be using too wide an aperture.

A Brown
19-Mar-2005, 07:14
Thank you for the replies. I am using a 150mm G-Claron with a 4X5 back. I usually always compose the shot such that the image fills most--not all--of the screen. I always thought the 150mm was more than sufficient for 4X5 work.

Any suggestions???

Jason Greenberg Motamedi
19-Mar-2005, 07:27
Have you used the lens for other kind of work? One of the problem I have seen with many of the G-Clarons is that they often get randomly put into shutters without measurement or testing. I once compared three 210 G-Clarons I had (don't ask)--two in shutter and one in barrel--and found that they were all different.

19-Mar-2005, 08:46
How far did you stop it down? The coverage wide open if I'm reading the Scheinder document right is less then 4x5.

You don't say how big the orginal is. Infinity is one thing. If it's a small item that is being photographed then it's less likely to be a coverage issue.

David A. Goldfarb
19-Mar-2005, 08:59
G-clarons are designed for reproduction, so it's not a bad choice of lens unless there is something wrong with your particular lens, as Jason suggests, or unless the work is really huge, putting you outside the optimal reproduction range of the lens.

Actually if the item is small it is NOT likely to be a coverage issue, because you get more coverage with near subjects than at a distance. If the item is very large, then you might have a coverage issue.

I'm still guessing that you just need to stop down more.

Paul Moshay
19-Mar-2005, 13:58
AJ, I use the 150 GClaron in my work photographing artwork and I always use 22 and get very sharp images on 4x5 Ektachrome. Make sure that all camera movements are square to the subject and the lighting is even. Also, always include the Kodak Q14 charts in the exposure for most accurate reproduction of the work.