What's the biggest print from a 1.6X crop factor camera

[arith]

I have just had a 30" x 20" print done of this scene and it is as sharp as here or even sharper.

I just wondered with enlarging software just how big can you go before you start to notice a loss of quality with a high resolution camera and lens.

[carregwen]

I too have just had a 30x20 print done from a 50D image. If I got a loupe and a bright light and went over it carefully, I doubt if I could spot anything amiss. And who is going to do that? I'd say that with a camera at least 12mp (which is most these days) a 30x20 print is going to look good, provided you used a decent lens, it was properly in focus at the time you shot it, and you sharpened it correctly.

Good shot, BTW

EDIT: A full-frame shot of the same scene, with all other things being equal, should obviously look slightly better as the relative enlargement is less. But could you tell the difference?

[arith]

I'm quite pleased with this aspect of the camera Rob, the biggest I ever wanted was 60" x 40" and that would be very special. With Topaz 2X JPEG software it might just do it so long as you don't inspect it with a magnifying glass.

[revi]

<snip>
EDIT: A full-frame shot of the same scene, with all other things being equal, should obviously look slightly better as the relative enlargement is less. But could you tell the difference?

You guys lots me there: are you talking here about sensor sizes (given the 1.6 crop vs. full-frame), or a crop from a photo as taken. If the former, why would the enlargement be less, assuming we have the same number of pixels to start with?
(if the latter, of course the uncropped shot should be better: more pixels, so more information)

[arith]

22 x 15mm approx sensor, I keep forgetting the actual size so I say 1.6 crop. I found somewhere obscure (dpreview I think) that the 50D has 2200 LW/PH although I don't know how that is worked out, and the nifty 50 has 2200 or greater resolution across the sensor at around f6.3. So I knew if I focused correctly and exposure was right and I sharpened (using Topaz Detail2) very carefully I should be able to get A2 size easily and possibly more, given how sharp my 10D is using Topaz I thought a lot more.
Jessops have a special offer at the moment of £7.50 for 30" x 20" print which is bigger than A2 so what better time to check it out and indeed detail you can't see in the small version above has actually come out in the print, and as I thought the shadow detail is better in the larger print.
So you could say I'm pretty much chuffed with it and now to think of something anoracish like a nice pic of a tram with sparky bits that somebody might even like to put their hands in the pockets and pay for, but I'm not expecting anything it is just an option.

[carregwen]

You guys lots me there: are you talking here about sensor sizes (given the 1.6 crop vs. full-frame), or a crop from a photo as taken. If the former, why would the enlargement be less, assuming we have the same number of pixels to start with?
(if the latter, of course the uncropped shot should be better: more pixels, so more information)

A full-frame sensor is much larger than a 1.6x crop factor sensor. Assuming you had one of each camera, both at 12MP, and assuming all other things being equal, and you shot the same scene, in theory the full-frame should be better quality. With the same number of MPs a smaller sensor has to have smaller pixels, which normally means worse quality such as more noise. That's one reason why point and shoot cameras (very small sensor) have poor IQ, and medium format film cameras (larger sensor than 35mm) have better IQ. When you print large the base size at which you start from generally must have an impact upon final quality. But you might have to look pretty close to notice it in some circumstances.

[revi]

Thank you,
that clarified things.

While we are busy with large prints, what kind of resolution do you aim for when printing at A2 or larger?

[arith]

Thank you,
that clarified things.

While we are busy with large prints, what kind of resolution do you aim for when printing at A2 or larger?

Cleared things up for me as well, although Canon said this new gapless design has bigger sensors than the 40D, and to tessellate the plane means some sort of triangle square or hexagon, actually could be rectangular I try for above Nyquist at all times apart from portrait stuff, and I don't ever get the chance to do that. cheers

So I go out planning around f6.3 with my 50mm or f4 with my 28mm, but of course dof might ruin plans and sometimes you don't need definition as much as less chromatic aberration and distortion.

It is all swings and roundabouts and this is the first time ever I made a print this big, although a hundred years ago at school I was taught to use the medium format with contacts bigger than 10" x 8" just joking they was big though.

[Colin Southern]

Hi Steve,

Short answer is "It depends on a number of factors, with viewing distance being (by far) the most important".

[arith]

Cheers Colin.

[Pictus]

How many megapixels do we need?
http://echophoto.dnsalias.net/ekr/in...els-do-we-need

[Steaphany]

My PP flow always concludes with DDI Software's Qimage. Regardless of making a direct print or preparation for sending off to a print house, Qimage always yields the quality I need. The largest print to date has been 20" x 30"

I have been in touch with photographers who have been able to create Qimage banner prints with measures of 8 and 10 feet with success.

[arith]

Cheers Steaphany, looks like I'm limited only by the printers since where I live the biggest they do is 4 feet wide well A0 really.

[arith]

How many megapixels do we need?
http://echophoto.dnsalias.net/ekr/in...els-do-we-need

Cheers, I went by the manufacturers claim of A2 straight out of the camera and concluded therefore A1 should be possible with careful sharpening, and it turns out that is easily possible since more detail is visible in the 20" x 30" than was seen on my monitor and from any distance; and this raised the question since some applications such as Topaz can intelligently fill in an enlarged image.

Of course there has to be a limit.

[Crovean]

New to this, but would you know if an images would come out good on a big print? like lets say a 20 x 30 like what you guys mentioned. Is their an ideal resolution to print on a 20" x 30"?

[arith]

New to this, but would you know if an images would come out good on a big print? like lets say a 20 x 30 like what you guys mentioned. Is their an ideal resolution to print on a 20" x 30"?

I don't know but read that 250 pixels per inch was enough however the above is only just over 125 pixels per inch and that has enough detail, I can't work out how that translates into a 10 MB jpeg file, 84 MB tiff file and 29 MB RAW file.

My 10D has 6.3 Mpixels and RAW file is 6.5 MB but the 50D has 15.1 Mpixel and RAW file is about anything even 30MB sometimes.

[Steaphany]

Here is an example of a large print I did with the Studio Edition of Qimage. I had Qimage produce an up scaled 4X image to achieve a resulting 10560 x 7040 pixel image. When printed at 32" wide, this yielded 330 Qimage pixels per inch or 82.5 imager pixels per inch. The print was ordered from Imagekind unframed and was shipped rolled in a mailing tube. The curl is still evident here. The scale that I have placed on the image is a metric drafting scale with an overall length of 12 and 7/8 Inches:



This is a close up of the print focused on the two manufacturer plate's on the engine. The lower one is obviously not readable, but the upper one is readable and states:

"AMERICAN LOCOMOTIVE COMPANY 40246 BROOKS WORKS JULY 1906"

The smaller text is harder to make out but is recognizable when you know what to expect. Below the plate is an engine servicing platform with the edge painted white. The clarity of the edge is easy to see:



Some points of note regarding the scale. This image has been magnified 39.3 times between the long dimension of the SD14's imager to the long dimension of this physical print. The print height of the manufacturers plate on the engine is roughly 17mm. This corresponds to only .433mm on the imager's surface or just 55 pixels. For those unfamiliar with the SD14, the imager measures 20.7 mm x 13.8 mm and has a 1.7 conversion. As a point of reference, when I have Qimage generate a Tiff file, it will typically be 200 to 250 MB.

[arith]

This is impressive stuff Steaphany. Good picture BTW.

[Colin Southern]

I don't know but read that 250 pixels per inch was enough however the above is only just over 125 pixels per inch and that has enough detail

Steve,

In the "real world" you just don't need resolutions like 240 dpi on most occasions. A quick example ...

If we take your 250 dpi and if we assume that that 25.4 millimeters per inch is actually close enough to 25 millimeters per inch then 250 dpi would equate to (250 / 25) = 10 pixels per linear millimeter or 10 x 10 = 100 pixels in a single square millimeter. Could your eyes resolve ONE HUNDRED tone changes in a single square millimeter? (mine neither - and probably not even with a magnifying glass) ... especially at normal viewing distances.

In reality I normally work at 180 dpi for my 44 x 22 inch prints (which is "normal size" for me) (usually the SMALLEST I ever print is 22" wide). Often people want enlargements of smaller files and if it's as low as 100 dpi I still don't hesitate -- and they still look just fine, unless you've got reading glasses on and are viewing from a "nose length". It's only when it drops to around 75 dpi that the deterioration becomes obvious up close (but even that looks fine from 5 or 6 feet away).

The worst I've EVER had to work with was the last photo ever taken of a chap before he died suddenly - the photographer's camera was set to VGA mode (640 x 480) and we had to chuck away about 1/2 of the 640 to turn it into a vertical print (due to distractions in the scene) - so in the end I had around only 1% of the ideal amount of info to work with and it STILL looked OK from about 6 feet away (although it was starting to look pretty bad up close) (I had to use Genuine Fractals and some very careful sharpening).

So the moral of the story is - if it's not cropped too heavily and it was shot with a camera that has at least 8MP then just don't worry about it - if it's a big print then you should be looing at it from a few feet back - and it'll look fine. If it were 50 MILES wide with pixels the size of football fields it would still look sharp from the international space station!

Hope this helps!

[Crovean]

That explanation helps a bunch Colin. I'm about to get a picture of my daughter printed on a 20x30 or maybe bigger. I was a little worried if it won't turn out as good like the 8x10 i tested it on. Do you have any tips on what too look at before getting it printed?