Print size

[Mark F]

As an old film guy in the process of converting to digital I have found the learning curve to be steep. The other day while reading about printing I read that the 5D produces a "4368 x 2912 pixel file, which naturally prints at about 12" x 18" at 240 ppi". I understand the math but not really the concept.  Who decided that using the formula gives the "ideal quality" print size for that size file?  What happens at larger than 12 x 18? Does noise start to show the same way that a large print from 35mm film would show grain? Is there a loss of contrast or a color shift? Does the print start to break down like it does on the monitor when the enlargement is too great? Can whatever happens be fixed in PS or other software? Do I have the whole thing wrong in the first place?

Thanks for the help.

MarkF

[wolfnowl]

Hi Mark:  The simple answer is that digital files don't work in inches, but pixels.  Therefore, the 5D image size of 4368 x 2912 pixels, divided by 240 pixels/ inch (dots per inch for the printer, but this is the simple answer), yields a print size of 4368/240 x 2912/240 or 18.2 x 12.13 inches.  You can print bigger images, but to print at the same resolution (240ppi), you need to 'create' pixels to fill in the new spaces.  This is call uprezzing, and there are a number of software programs, including Photoshop, that will allow you do that.

Now there are many people on this list who have much more specific knowledge about this, and I leave the floor to them...

Mike.

[TMcCulley]

As an old film guy in the process of converting to digital I have found the learning curve to be steep. The other day while reading about printing I read that the 5D produces a "4368 x 2912 pixel file, which naturally prints at about 12" x 18" at 240 ppi". I understand the math but not really the concept.  Who decided that using the formula gives the "ideal quality" print size for that size file?  What happens at larger than 12 x 18? Does noise start to show the same way that a large print from 35mm film would show grain? Is there a loss of contrast or a color shift? Does the print start to break down like it does on the monitor when the enlargement is too great? Can whatever happens be fixed in PS or other software? Do I have the whole thing wrong in the first place?

Thanks for the help.

MarkF
[a href=\"index.php?act=findpost&pid=186614\"][{POST_SNAPBACK}][/a]

When printing it is generally acceptable to print you image at 180ppi to 480 ppi without resizing your image.  The smaller the ppi the larger the print but (depending on the printer) you may get some image degredation that may or may not be acceptable.

It is just convientant (not ideal) that the print size comes out to 12x18 but it is not particularly important(unless you own a large quatity of 13X19 paper).  The statement you are refering to is probably some advertising hype and is not a statement of prefered quality

I suspect, for most images, upon completion of the pre-printing workflow the image no longer matches the begining pixal dimensions.

Tom

PS You might want to watch Michael's tutorial "From Cameral to Print".  This is one of the best learning tools I have used and answers many questons like this one.

[Eric Myrvaagnes]

Mike beat me to it.

I'll just add that the mysterious "240" is simply a commonly accepted resolution that is generally considered "good enough" for high quality prints that might be viewed reasonably close up. Less than 240 and you can see the dots (but you can get a bigger print without uprezzing); more than 240 and you don't really gain much visual improvement (and you are limited to a smaller print).

"Uprezzing" adds new pixels that are generated (via various arcane methods) from nearby pixels in order to avoid having individual dots show.

I hope this helps.

[sojournerphoto]

Mike beat me to it.

I'll just add that the mysterious "240" is simply a commonly accepted resolution that is generally considered "good enough" for high quality prints that might be viewed reasonably close up. Less than 240 and you can see the dots (but you can get a bigger print without uprezzing); more than 240 and you don't really gain much visual improvement (and you are limited to a smaller print).

"Uprezzing" adds new pixels that are generated (via various arcane methods) from nearby pixels in order to avoid having individual dots show.

I hope this helps.
[a href=\"index.php?act=findpost&pid=186641\"][{POST_SNAPBACK}][/a]

TBH I think that print quality does improve as the resolution increases above 240ppi, certainly beyond 300ppi for images viewed closely.  The idea that you don't need to upres an image between 180 and 480 ppi is because the print driver will do this automatically (some better than others). Having said all that, 5D files printed up to 24 by 16 (or even 30 by 20 in some cases) generally look very nice.

Mike

[NigelC]

TBH I think that print quality does improve as the resolution increases above 240ppi, certainly beyond 300ppi for images viewed closely.  The idea that you don't need to upres an image between 180 and 480 ppi is because the print driver will do this automatically (some better than others). Having said all that, 5D files printed up to 24 by 16 (or even 30 by 20 in some cases) generally look very nice.

Mike
[a href=\"index.php?act=findpost&pid=186734\"][{POST_SNAPBACK}][/a]

I've got an interest in this as I have a 5D and have just acquired an Epson 3800 A2 printer. Do you mean that the files look very nice at 24 by 16 when ressed up (e.g. Photoshop bicubic) to print at 300 dpi or more, or just by letting the printer do that job

[jbrembat]

I've got an interest in this as I have a 5D and have just acquired an Epson 3800 A2 printer. Do you mean that the files look very nice at 24 by 16 when ressed up (e.g. Photoshop bicubic) to print at 300 dpi or more, or just by letting the printer do that job
[a href=\"index.php?act=findpost&pid=186798\"][{POST_SNAPBACK}][/a]

Eposon does not like 300 PPI. Use 360 PPI.

Jacopo

[Slobodan Blagojevic]

The best cure for this type of scholastic discussions is to get out, visit a couple of workshops or seminars where photographers display their printouts and see it for yourself. When you see those 40, 50, 60 inches long enlargements, you will understand why I called this type of discussion 'scholastic'. Not trying to preach, just describing my own process of transformation from an armchair measurbator, to a believer that pixels do not matter that much (especially not those coming from a 5D-type camera). At the end, it does not really matter how you get there ('naturally' or not, interpolation this or resizing that), it is the final result that counts.. and that result is stunning.

Slobodan

[sojournerphoto]

I've got an interest in this as I have a 5D and have just acquired an Epson 3800 A2 printer. Do you mean that the files look very nice at 24 by 16 when ressed up (e.g. Photoshop bicubic) to print at 300 dpi or more, or just by letting the printer do that job
[a href=\"index.php?act=findpost&pid=186798\"][{POST_SNAPBACK}][/a]

I use all sorts of approaches to be honest - depending on what I'm trying to achieve. My printer isn IPF 5000, so the native input resolution of the driver is 600ppi. I think the epson is either 360 or 720.

However, slobodan is right really. I started out with the 5D two years ago being unsure as to how big I could print, then ran a few off and don't worry much these days. I have 24 by 16s straight out of lightroom that look nice (in spite of the 'inferior' output sharpening) and 30 by 15 crops that have had very careful upressing and a bit of grain added to help the perception of sharpness, all of which look really nice on the wall. Suffice to say that I'm holding off getting a 24 inch printer so that I can save up for a 44 inch printer next time. I really enjoy making big prints, just need a bigger house or more buyers... (and when you start stitching it's even easier).

It's worth buying some paper to have a play on - then just be amazed and enjoy.

Mike.

[Mark F]

Thanks to all for your answers.  I want to make larger prints, 20 x 30 and 30 x 40, and have been struggling trying to understand whether the 12mp 5D will do the job or if I have to go to the larger models.  It seems like I would be pushing the 5D to its limit for a 20 x 30.  Oh well, its only money.....

[sojournerphoto]

Thanks to all for your answers.  I want to make larger prints, 20 x 30 and 30 x 40, and have been struggling trying to understand whether the 12mp 5D will do the job or if I have to go to the larger models.  It seems like I would be pushing the 5D to its limit for a 20 x 30.  Oh well, its only money.....
[a href=\"index.php?act=findpost&pid=187252\"][{POST_SNAPBACK}][/a]

TBH, it also depends on the image and what you want from the print. You can't create missing detail, but the 5D output is so smooth that it enlarges really well.

Let us know how you get on - print a few up using a poster function - in fact I'll try it in the next few days on some cheap paper.

Mike