Good enough to print? What print size?

[Set_Nights]

This is probably a really stupid/newbish question but how do you know if your photo is good enough to print :bonk:? How do you determine what size your photo should be printed at? Is there a guideline of a certain amount of pixels = a certain sized print ? I mean obviously you could have all the pixels in the world and still have a naff photo but surely even the best photos, taken at a small size, can only be blown up so much. Hmm...

 

[Chappers]

This is a difficult question to answer. The standard reply is to look at the size of the image in pixels, divide this by the print resolution (in dpi) and that gives you the maximum size you can print. However...

The problem is this can give you a size smaller than you can really get a good print . Mainly because dpi ( dots per inch) isn't the same a ppi ( pixels per inch) and there isn't really a simple conversion.

To give yo and example I have some images that were taken on a Canon 300D several years ago. A 6 Mp camera. Now using the dpi figure , the largest size I could have printed was around 7" x 10". Now OK it wasn't the kit lens I was using but something a lot better, but I have so 20" x 30" from the camera that look sharp even fairly close up, ( about 20" ). So how does this happen.

Well as I said earlier there is no real correlation between dpi and ppi. Plus there is a lot happening in image processing. Not adding excessive sharpening will help. Use output sharpening rather than input sharpening, as the later is applied to the output rastered image. Plus the quality of the printer will help as well, as does the rendering software that it is using.

So as a rule of thumb you can use the resolution in pixels/ dpi to give you a good guide. But don't be put off if the calculation says 12 x 18 and you want 20 x 16. You'll still probably get a good print.

Just don't over process the image, whatever size you want

 

[Set_Nights]

What is the difference between different type of printing? I'm looking at this website:

http://www.amimage.co.uk/

If you look at the 3rd page of the price list I assume that is the digital options but what is the different between the options (D-Lab prints, wet process chromira prints and ink-jet epson 9900s prints)?

 

[Chappers]

D-Lab is a Agfa digital printer. It uses a Laser to write to photographic paper, and is processed in conventional RA4 type chemicals. It's normally limited to 18 x 12 prints

Chromira is a similar process, using lasers to write to conventional photographic papers and then processed as with the D-Lab . The difference is simply in size of prints that can be produced. The D-Lab has it's own processor built in ( It is in fact a minilab) the Chromera requires an external processor due to it's ability to take larger paper. In this case it looks like it limited to 30" Although Chromera's are available to take rolls up to 52" wide

Both these as you will see use conventional photographic paper

The Epson is a wide format inkjet printer. It can use a number of different papers to print where as the D-Lab and Chromera you are limited to a small range of paper surfaces. With inkjet you have a much wider variety. Provided the lab is willing to use them.

Hope this helps