Re: Large print - quality issue

[Andrew Davidhazy <andpph@xxxxxxx>]

Jonathan,

First of all I do not claim “expertise” in this area and would much appreciate hearing from others that contemplate this question.

I don’t think that the images are RAW has much to do with it. At that size of a final print you probably can get away with a file that is 100 ppi or about 4 ppm. So your sensor is 4256 pixels in the long dimension. It means that at 100 ppi you could make a print that is 42 inches (1000 mm) long that is “passable” at respectable viewing distances.  You may be able to get away with even lower specs and approach your desired size but I don’t know for sure. The kids images were probably made so they would take up a larger portion of the frame than if they had been standing in the real landscape so their files would need to be prepared so they match the background image in terms of ppi and then dropped into the background image. The “quality” of the background and that of the kids then would be the same. 

Anyone else?

Andy

On Aug 22, 2014, at 5:08 PM, Jonathan Turner <pictures@xxxxxxxxxxxxxxxxxxx> wrote:

Hello,

I have a question regarding print quality;

I'm working on a project for a gallery (here in the UK) which involves producing composite images. The composites are made from images of school kids photographed against a plain backdrop, which are then cut out (in photoshop) and placed into a 'scene', to form a series of tableaux.

All the images (backgrounds and school kids) are shot in RAW on my Nikon D700. The gallery want to print the final composite images at a size of 1600mm on their longest edge, so we have taken a couple of A3 cropped sections from an image which I sized at those dimensions to see how they will look.

The main problem is that there is (obviously, I guess) a disparity between the background 'scene' image, and the 'composite element' images (the cut out school kids) in terms of image quality...the school kids look OK but the background scene image looks grainy. Whilst the final images were always meant to be presented as composite tableaux (it was never intended that they look like 'real life' scenes) the difference in the image quality (between image components and background) seems too great. Obviously I understand that the background scene is being blown up way bigger than each cut-out element of the image, and so is bound to look more grainy, but wondered if there was a way to print a RAW file at that size without so much loss of quality...? How big can a RAW file go before it starts to break up? I've been told that I should be able to print a Billboard sized image from a RAW file, but I suspect that is a different kind of printing technology to that of printing a digital photograph... If I can print the background image without too much loss of quality then the composite elements will sit better within the scene...at the moment they stand out a mile because they are very clear/non-grainy by comparison.

Any advice on this gratefully received.

Cheers,
Jonathan.

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Jonathan Turner - Photographer M; 07796 470573 W; www.jonathan-turner.com