Max Print Size from 10 mp APS-C?

[Brian Gilkes]

Wel lit depends on lots of things.
A couple of years ago I could do a reasonabe job of  6 MP image to A2.
As I type I'm printing a 6 MP image to 43" x 64.5" for a show in LA.
It looks pretty good.
Of course one could argue fine detail is missing if you look closely. The lens has limits.
The trick is to maximise the perceptual qualities so the viewer thinks the print simulates reality.
This requires a strategy based on perception as well as physics.
The first step is deconvolution to improve image resolution and remove as much as possible of the demosaicing.
Next is local contrast enhancement . There are a number of ways to approach this.
Then the light distribution is modified .
The tones can be redistributed with custom colour spaces.
Upsizing can be effected with beta spline , sinc etc - much better than bicubic.
The final sharpening strategy is critical, and depends on the paper , the enlargement and all the things that have gone on before.
All these edits use gradient masks in various opacitiess to directt the vision and create attenuation.
It takes a heap of research and practice to learn the moves and to apply them requires developing a strategy for each individual image. It's like chess really.
I have to say Photoshop is very limited in this and one must look at a lot of very specialist software.
The potential though, is very exciting. Needless to say i will not be reopening my  dakroom
have fun
Brian
www.pharoseditions.com.au

[BruceHouston]

Thanks all, for the kind response!

Bruce

[Plekto]

20x30 with 10MP is stretching things quite a bit, especially for landscapes. I personally wouldn't print bigger than 16x24 in general with 10MP (and there is a significant lack of detail if you go that big), though it depends quite a lot on the image. Some images don't need that much resolution if you don't have fine detail.

I agree.

Let's say it's a 3800*2600 sensor.(keep the math simple)
Dye-sub printers print out at 400dpi and so that's a good yardstick.

That works out to 9.5 X 7 at no enlargement.  The most you can reasonably enlarge before it starts looking very grainy, IME, is about 200dpi dye-sub.  (4x total size).  that's 19*14 for a typical 10MP sensor, give or take.  30X20 is going to be close to 125DPI and look exceedingly grainy.

Inkjet of course, use different technology, but the results are nearly the same.  To print absolutely huge, you need a really large sensor, no two ways about it.

[sojournerphoto]

I agree.

Let's say it's a 3800*2600 sensor.(keep the math simple)
Dye-sub printers print out at 400dpi and so that's a good yardstick.

That works out to 9.5 X 7 at no enlargement.  The most you can reasonably enlarge before it starts looking very grainy, IME, is about 200dpi dye-sub.  (4x total size).  that's 19*14 for a typical 10MP sensor, give or take.  30X20 is going to be close to 125DPI and look exceedingly grainy.

Inkjet of course, use different technology, but the results are nearly the same.  To print absolutely huge, you need a really large sensor, no two ways about it.
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Two years ago that was my view, but experience suggests that it depends on what the viewer expects to see and how capable you are of delivering that. I'm currently wrestling with printing some big images from my P&S - which has 9Mp, but which doesn't provide anything like the clean images the 5D or 1Ds3 produce. Each image needs careful individual attention, and some are still evading me, but I will get useable prints from most I think.

Key issues are viewing distance (obviously) but also what level of detail is present in the image or expected by the viewer, how lack of detail/resoultion is presented - 35mm film presents grain as resolution breaks down, but that is accepted by most viewers as a part of the medium.

Have a go, work out why your prints don't work and then try to devise approaches to address the problems. Then share them - Brian's post above has helped me, even without a lot of detail as to his exact approaches and software.

Mike

[Plekto]

I've found, though, that 200DPI dye sub or the equivalent on an inkjet is about as grainy as you can go and get away with without people noticing.  Maybe 150 at most.

If you want to print big, you need more points of original data, which is why slide film and a scanner still is a popular alternative.(~3000DPI even from 35mm film nets a large amount of data for very little money)

Even a Minolta Dual IV gives you 3200DPI/14MP for under $300 these days.