Questions about "high-resolution" files for print, please?

Easy question: what constitutes 'high-resolution' file for printing?

Main reason for asking is that I'm saving down to .jpeg at 800 x 600 (not sure the DPI factor) and the prints are coming out amazingly sharp, IMO.

The files are printing with more sharpness than my newer Dell monitor resolves an on-screen image.

Also, (ducking) I've had recent prints done at the local Wal-Mart (convenience factor) and to my untrained, but discerning eye, they appear to be pretty nice prints!

That said, what SHOULD I be doing?

Thank you.

dave

snyderman wrote in post #11045227
Easy question: what constitutes 'high-resolution' file for printing?

Main reason for asking is that I'm saving down to .jpeg at 800 x 600 (not sure the DPI factor) and the prints are coming out amazingly sharp, IMO.

What size are you printing at? It's quite feasible that you can print an excellent 4x6 from those dimensions.

But what I would do is in Photoshop, go to Image > Image Size and uncheck "Resample". Then adjust the size to the intended print size. If the PPI number ends up anywhere between 200 and 400 you're good to print. This method does not lose any pixel data when resizing.

ChasP505 wrote in post #11045317
What size are you printing at? It's quite feasible that you can print an excellent 4x6 from those dimensions.

But what I would do is in Photoshop, go to Image > Image Size and uncheck "Resample". Then adjust the size to the intended print size. If the PPI number ends up anywhere between 200 and 400 you're good to print. This method does not lose any pixel data when resizing.

Chas:

thank you for the helpful info. I'll go back and see what PSE7 is saving to. I've been blown away printing recent work at 4x6, 5x7 and 8x10. It must already be saving at a decent PPI, but I'll double check current settins and replace with yours.

Thanks again.

dave

My question, which I didn't ask before, is WHY are you reducing your images to 800 x 600 rather than saving them at full size? Jeez, you're shooting with a 5D and a 7D... Why are you throwing all that image data in the trash?

ChasP505 wrote in post #11045624
My question, which I didn't ask before, is WHY are you reducing your images to 800 x 600 rather than saving them at full size? Jeez, you're shooting with a 5D and a 7D... Why are you throwing all that image data in the trash?

Primary reason for asking. I did feel like something (big, obviously) was being left on the the table. As printing is something new, full size files weren't an option printing at my local Wmart.

I'm still in the phase of correcting certain processes between processing and printing. This is the first time I'd really thought through the process which lead me to ask for help.

Thanks again. I really appreciate your experience and insights on how to manage through the post-to-print thought process.

dave

snyderman wrote in post #11045833
...As printing is something new, full size files weren't an option printing at my local Wmart.

Understandable, but 800 x 600 is really too small for even 4x6's.

For a 4 x 6, I'd probably go with 1200 x 1800.

For a 5 x 7, I'd use 1500 x 2100.

Epsons "natural" resolution is 360dpi per colour. Although my R2880 claims to be able to double that to 720 I have never tested at that resolution and 360 is plenty anyway.

What I have tested is the lower limit of print quality and from experience know that I can drop to 180ppi and the print will appear just as good as at 360ppi. Below that I can begin to see the difference. Thats with a magnifying glass and my nose almost on the paper. So 180 would be my personal definition of the term.

The reality is viewing distance needs to be considered. The common example often quoted here is an advertising hoarding, Billboard as those across the pond would know it. Seen from several hundred feet away, the pixelation is unnoticed.

Edited to add: Theres no need to resize (and discard valuable data) the original. Save the original at full resolution and resize a copy to the printers requirements.

Lowner wrote in post #11046056
Epsons "natural" resolution is 360dpi per colour. Although my R2880 claims to be able to double that to 720 I have never tested at that resolution and 360 is plenty anyway.

I audited a printing seminar a few weeks ago and the presenter, who is associated with the Epson Print Academy, said the company line from Epson is that 180-480 ppi is good.

Chas,

Thats interesting that Epson themselves say that. I get very confused with my R2880, which depending what you read, talks of 360/720 and 1440dpi.

How the extended dpi are achieved (if indeed they are)using the natural 360 I have no idea. I am aware that its named the 2880 because the 8 ink cartridges x 360 = 2880, whatever other "trickery pokery" is going on.

Just to be clear... I'm talking about PPI, not DPI. My HP has a native DPI of 600, and the presenter suggested a safe quality PPI range of 200 to 400.

http://www.retouchpro.​com/index.php?page=reb​roadcast

http://www.retouchpro.​com/live/rodneyinkjet.​pdf

800x600? Yikes, that is tiny - smaller than what I use when emailing downsized photos. I just uploaded a file to my print supplier for a 24x36, and it was 4000x6000 pixels and I was worried that it was on the small side.

-edit-
To answer your original question though, what "should" you be doing? That is really on a per photographer basis, but if it were 2005 again, I would say get an Espon printer, print your own photos; however it is 2005, and using someone like MPIX.com is definitely cheaper. I would not put anything out there in client's hands from Walgreens or Walmart, since they can just look on the back and think to themselves "I could have done this myself". When you get them from MPIX, they are on professional paper, not just whatever is cheapest to buy for Walmart consumers. Also, you get many other options like custom coatings, paper types, framing, canvas mounts, standups, etc...

If not dealing in volume, then print your own...if you print more than 100 prints a month, I would use a service like MPIX. As far as the size thing - yeah, why size down then print? Why not just print from the source file? If anything it just seems like more work that you do not need to do.