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Old Apr 25, 2008, 10:29 PM   #11
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An 8x10.
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Old Apr 26, 2008, 7:06 AM   #12
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VTphotog wrote:
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While the ideal solution is a camera/lens without barrel or pincushion distortion, there is a workaround in post-processing. there are Photoshop plugins available for just this sort of correction. My Photoimpact has it as part of the program. The free RAW converter (which will also work with other image formats), Raw Therapee has lens correction as well.
While those and similar tools may work well for landscape and architectural images, they perform this magic by playing with the pixels. This often results in a loss of detail. That would be unfortunate since the OP is looking for detail and this would occur in parts of the image where detail is already probably less that desireable.

I still think the best solution is to frame the image of the artwork such that it is far from edge and corner softness, vignetting, and geometric distortion.
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Old Apr 26, 2008, 11:17 AM   #13
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It is not clear to me that using the center would be an improvement over using software to adjust out the distortion. By using the center, you are thowing away some pixels meaning that you will have to "stretch" the remaining pixels to get to the same size print. And as TCav pointed out, software adjustment can mean loss of detail.

I would suggest trying it both ways and see what works for you with the particular lens you have.
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Old Apr 26, 2008, 11:33 AM   #14
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BillDrew wrote:
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It is not clear to me that using the center would be an improvement over using software to adjust out the distortion. By using the center, you are thowing away some pixels meaning that you will have to "stretch" the remaining pixels to get to the same size print.
I agree that not zooming in tight on the subject will slightly reduce the detail at the center, but it could greatly increase the detail at the edges and corners of the subject. And so long as the resultingimage of the subjectis of sufficient detail, it will require a lot less post processing where detail could take another hit.

But I agree that the results will differ from camera to camera (lens to lens), but also from angle of view to angle of view, focusing distance to focusing distance, and aperture to aperture. Trying it with his current 6MP camera could be time consuming,and maybe even futile.

That is not to say, however, that I don't think he should try.
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Old Apr 26, 2008, 12:30 PM   #15
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Whats wrong with a 50mm lens and using Close Up filters if you have to move in on a small piece of artwork?
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Old Apr 26, 2008, 2:17 PM   #16
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Wow! I hoped for good answers from you guys, and I have really, really enjoyed reading what has been discussed so far. Let me recap and you can correct any misunderstandings I might have made I read, okay?

1. It's a good idea when doing the flat copywork to not have the subject fill the photo.

2. If it doesn't fill the screen, then I'll be throwing away pixels when I crop, so start big--bigger than 6MP probably.

3. If using a zoom lens, don't be too near either extreme of zoom to reduce the distortion.

4. If purchasing a prime macro (single focal length) lens, I might be able to find one used (expect the range to be "expensive to heart stopping"). I could find a prime lens first and then buy a compatible dSLR body. Maybe I understand that Sigma makes lenses that are interchangeable from brand to brand?

5. I could also do post-processing workarounds that might fudge pixels a bit. I think if I expect to be doing lots of copywork I should try to get the pics right the first time around, though.

As a side note on the lighting I use, I experimented a whole lot and finally found that my best lighting is flourescents with very high CRI values. I get good color reproduction that way--almost as good as diffused sunlight. Ironically I found that JoAnn Fabrics sell a lamp that is very, very good for my purposes--it's developed for looking at fabrics in true color.

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Old Apr 26, 2008, 3:44 PM   #17
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OP again.
So I've been looking at local Craigslist and I see lots of Nikon F-mount lenses out there, but none that don't have a field of zoom. I'm looking for one with a single number mm, right? Like 50mm? Called a "Prime Lens"?
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Old Apr 26, 2008, 4:46 PM   #18
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edtech2020 wrote:
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... Maybe I understand that Sigma makes lenses that are interchangeable from brand to brand?
Noooooo.

Sigma makes lenses for a lot of different SLRs, but lenses made for Canon will not fit Nikon, etc., and verse viesa, no matter who makes them.
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Old Apr 26, 2008, 5:38 PM   #19
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This was taken with my Fuji S700 and a #2 and #1 close-up filters. The barrel distortion is negligible. The cost was minimal. A couple close up filters are a lot less than a lens. The photo is full frame, no cropping and unretouched in any way. If the lens isnt EXACTLY perpendicular to the center of your artwork then distortion will appear no matter what you do.
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Old Apr 26, 2008, 5:43 PM   #20
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A local Craigslist [Nikkor AF 60mm Prime f/2.8] is asking $300. Prime is what I'm after, right? I could buy the Nikon body to go with it.

I'm not sure the close-up filters are what I'm after, because sometimes I'm wanting to archive 18" by 18" scrapbooks and the distortion from my little zoom lens is something fierce when it's zoomed all the way out.
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