[Don Boyd]

Are you quite sure, based on experience, that you need to print at 240 dpi? I have printed a number of large images at both 180 and 360 and find little to tell one from the other. Some day I should sit down and do a test run of prints at increasingly lower theoretical resolution and see where it really falls apart, and why.

While I'm very pleased with 20x30 prints from my K-5, I don't think I would be happy going much larger. Since I have an old Pentax 645 and a nice set of lenses, I keep hoping the price of the 645D will drop out of the stratosphere. Dream on, huh.

Bob, I may have tried printing at 180 at one point - seems I wasn't very happy with it. I assume that larger prints at lower print resolutions would be problematic, but am not sure about that.

If you haven't seen it, you might check out the Luminous Landscape shootout between the 645D, the Phase One P40+, both 40meg sensors, and, for fun, the Canon 1Ds3 (21meg) and a Leica M9 (18meg).The two MF rigs ran neck and neck. What was most interesting to me was that, though the 1Ds3 was left in the dust (no clear theory on why) the M9 was not. So maybe I should be lusting after a Leica instead, huh?

Yes, I saw that when it first came out. That is part of the reason I got so excited about the 645D to begin with. Have you seen this shootout among Big Cameras - 8x10, 4x5 (film) and MF digital? Big Camera Comparison | On Landscape

I'm wondering if manufacturers have reached the near limits of pixel quality, and that, as many are suggesting, increased pixel densities are more for marketing purposes than real world solutions for larger print size.

[bkpix]

Don,

I have read -- and I confess that I haven't tested this -- that the printing resolution that is required to get the same perception of quality in a print actually goes down as the print size goes up.

By that theory, a 4x6 print of the same image will require higher resolution -- like 720 dpi -- than a 20x30, which can get away with resolution as low as 120 and still look as good. I'll try to dig out the source for that.

Better yet, I might try the experiment myself.

It does make a certain amount of intuitive sense.

Also, thanks for the link to the big camera comparison.

Bob

[dgaies]

I have read -- and I confess that I haven't tested this -- that the printing resolution that is required to get the same perception of quality in a print actually goes down as the print size goes up.

I assume this is based on the fact that the distance that one typically views a 4x6" photo is a lot shorter than the distance from which one views a 20x30 image.

[bkpix]

I think there was more to it than simply viewing distance -- something more akin to the psychology of vision -- but can't remember for sure.

One other observation: I do all my printing on matte/watercolor/drawing paper, which has some ink spread. Anyone printing on photo glossy paper will probably see finer distinctions as a result of resolution issues.

[amc654]

I do all my printing on matte/watercolor/drawing paper, which has some ink spread. Anyone printing on photo glossy paper will probably see finer distinctions as a result of resolution issues.

I second that--when you know you're going to have dot gain/ink spread, you don't want as high a print resolution; with a harder-finish paper, you generally will need a higher res to get a sharp image.

[TomB_tx]

Don,

Since you were looking at stitching a series of photos, Steve Huff just posted an article about landscape stitching using a Leica M9 that you might want to see.
A stitch in time…with a Leica M9 by Kefyn Moss | STEVE HUFF PHOTOS