enlarging files

[leorah72]

hi all...i am new to digital and have what might be a basic question.  i am currently shooting with the original rebel (and contemplating upgrading to the canon 5d).  i recently had a 16x20 made from a raw file from the rebel.  i did nothing to it except convert it to a jpg, and take it to be printed.  the result was ok, not great.  at first glance it is fine, but there is definately digital noise visible.  is this bc i should have done something in post processing different?  is it bc my file was not big enough from the 6 mp rebel to make a 16x20?  is there a specific way to enlarge it that i should have done before sending it to be printed?  help!

as i said, i am contemplating the 5d, but it is a big investment, and want to make sure that i dont have similar probs enlarging with those files.  i want to know what i am doing!  if anyone can fill me in, or direct me to an easy to digest book/article/workshop, let me know.  thanks in advance!  leorah

[jbrembat]

hi all...i am new to digital and have what might be a basic question.  i am currently shooting with the original rebel (and contemplating upgrading to the canon 5d).  i recently had a 16x20 made from a raw file from the rebel.  i did nothing to it except convert it to a jpg, and take it to be printed.  the result was ok, not great.  at first glance it is fine, but there is definately digital noise visible.  is this bc i should have done something in post processing different?  is it bc my file was not big enough from the 6 mp rebel to make a 16x20?  is there a specific way to enlarge it that i should have done before sending it to be printed?  help!

as i said, i am contemplating the 5d, but it is a big investment, and want to make sure that i dont have similar probs enlarging with those files.  i want to know what i am doing!  if anyone can fill me in, or direct me to an easy to digest book/article/workshop, let me know.  thanks in advance!  leorah
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Hi,
  have a look at [a href=\"http://www.photoresampling.com]http://www.photoresampling.com[/url]

You can find an article explaining PPI and DPI.
You can download for free PrinterData, a windows utility to know your printer, if you have one.
You can download a demo version of PhotoResampling. In this product you can find a tool to prepare the image for printing.

If you are interested on denoising, you can download a demo version of PhotoDenoising.

Hope this helps

Jacopo

[David White]

raw file from the rebel.  i did nothing to it except convert it to a jpg, and take it to be printed.
[a href=\"index.php?act=findpost&pid=116114\"][{POST_SNAPBACK}][/a]

I think that you have answered most of your own question.  Converting a large file to jpeg probably introduced a lot of the artifacts that you are seeing.  Keep your files in TIFF format to avoid most of the problem.  You are starting out in RAW which is a good thing, but don't expect to get a quality print, especially with a large uprezzing when you convert to jpeg.

You didn't mention anything about the processing of the file.  Over sharpening can also introduce problems in the printed output.

The method of uprezzing can also influence the quality of the output.  There are probably as many methods of increasing the size of an image as there are experts in the field.  For starters, make sure that you are using bicubic smoother.

[Schewe]

if anyone can fill me in, or direct me to an easy to digest book/article/workshop, let me know.  thanks in advance!  leorah
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See: [a href=\"http://www.digitalphotopro.com/articles/2005/septoct/artoftheupres.php]The Art of the Up-res[/url]

[Ken Tanaka]

See: The Art of the Up-res
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This gives me an opportunity to publicly thank Jeff Schewe for that article.  His recommendations were genuinely helpful when I was faced with a real "up-res" challenge just over a year ago.  

In brief, Toronto's Art Gallery of Ontario licensed several of my images for an exhibit in early 2006.  Nearly all of their selections were captured with my 1D Mark II camera.  The images had wonderful tonality (if I do say so myself) but they were 8 Mp.  This would pose a challenge for several of the images which the AGO planned to display at approximately 22' x 12'.  Nervous?  Me?  Naw.  

Cutting to the chase, in addition to determining the characteristics of the VuTek printer (to be used to print the images) I followed many of the suggestions that Jeff offered in that article.   The results were truly superb.  ([a href=\"http://www.pbase.com/tanakak/agoexhibit]These few snaps[/url] don't convey the quality but do show the sizes of some of these images.)  The enormous images were every bit as clear and smooth as they were at 8 Mp.

So thank you, Jeff!  I recommend that everyone get a copy of that article and save it for ongoing reference.

[Schewe]

So thank you, Jeff!  I recommend that everyone get a copy of that article and save it for ongoing reference.
[a href=\"index.php?act=findpost&pid=116406\"][{POST_SNAPBACK}][/a]

You're welcome...thanks for the kind words.

:~)

[Alaska]

This is a nice how to uprezzing by Jack Flesher.

http://www.outbackphoto.com/workflow/wf_60/essay.html

Gave it a try and it does work nice on the Canon ipf5000 for 17 x 24 inch prints out of a Canon 20d.

Jim

[jbrembat]

Converting a large file to jpeg probably introduced a lot of the artifacts that you are seeing.

It is not true. A good quality jpg is very nice, similar to the original.