printing quality question

[Cyza]

So am going to order about 20 prints on line at a size of 18 by 12 inches.

The site I will be ordering from has an upload limit of 5mb per file, the thing I want to know what plays a bigger role on the overall quality of the printed picture, "image quality" or "D.P.I." ?

for example which would produce better results,
200 DPI at 12 image quality
or
250 DPI at 10 image quality.

My photos are taken with a canon 60D (18 mega pixels) so really can't exceed about 275-300 DPI with out having to enlarge the image it self in PS, but what would be the optimal DPI to image quality ratio in your opinion at 18x12 inches.

thanks a lot for any help, I really do know very little about printing. (will be my second time printing my images)

[I @ M]

A few thoughts on the subject.

In this day and age 5mb is a small jpeg file, may I suggest checking out online printing firms that aren't living in the past.

With DPI, be guided by the company that is doing the printing, they should have the DPI that they require to print at in their requirements for files. Some print labs specify 200 DPI as the maximum because that is what their actual machines print at. Others are quite happy to accept 300 DPI and either print at that or re scale the job before it goes through the printing process.

I haven't seen an online print firm that has asked for less than maximum quality files and if you care enough about your images to take them, process and then print them you should then provide the best possible quality file to be printed.

I would be going back to my first point and finding a company that accepts unlimited file sizes and has the DPI requirements for images on their web site and supplying them with maximum quality images to print. :)

[ricktas]

In this day and age 5mb is a small jpeg file, may I suggest checking out online printing firms that aren't living in the past.



Amen to that statement. I would be looking at another printer too!

[FallingHorse]

I second the motion!

[Cyza]

the place from which I'm planning on ordering the prints from is unbelievably cheap, when ordering 20+ the 18x12 prints are 2 dollars each, and when ordering 50+ they're 1 dollar each. I had ordered 12x8 prints in the past (with which I also obviously had a 5mb cap) and I was very happy with the quality, not to mention the sites communication and quick delivery.

That being said for more important prints (end of year project for media) I think I will follow the advice and look else where to get higher quality prints with no limitations to size, thanks guys :)

[I @ M]

Cyza, RGB http://www.rgbdigital.com.au/pricelist/photographic-prints.html in Brisbane have pretty good prices ( + $12.00 delivery ) and I am pretty sure when I have used them in the past there has been no size limitation on uploads.
There service and quality are good.

[Cyza]

after reading the initial posts I had a look around for other australian printing companies, and I came across rgbdigital, they are one of the better priced companies however at 9 dollars a print vs 2 dollars there is a significant price difference. I know you get what you pay for in most cases, but buying things previously from photoenlargments.com.au in the past I was very happy with the quality.

[junqbox]

I've used these guys before with fantastic results. Depending on the content of the image, I have had to sometimes take it down to 200-250ppi to reach the 5Mb target with no loss of quality.

[Cyza]

when you did use them, were you ordering 18x12 prints or smaller?

[junqbox]

Always the 18x12's, best value I've found around. Photographic paper, quick turnaround, easy to deal with.

[ameerat42]

A few questions here, prefaced by: since you seem to want to use this service.

The 5 MB quoted, is that the size on disk? I suspect so, that is, the result saved to disk after jpeg compression.
If so, then I think that for that size print 5 MB is really asking a lot of a file to retain much info for such a sized print.

BUT. To answer the question you struggled with at the top of your post, you have to maintain as much image quality as you can from your original to then take a 5MB file to that size. It's not just a matter of IQ vs DPI as they are interlinked.

Now your problem is how to get the size down from your 18 MPx camera to suit the printer's requirements. Presumably you have the likes of Photoshop.

Firstly, you'd have to physically re-sample the file, ie, go from 18 MPx original to something that's going to be 5MB big on disk and 18" x 12" at some DPI. You will have to calculate the final DPI and set this in Photoshop. Throughout the whole exercise, I would always save the file at Quality 12. You ensure this by doing a "File-Save As...", not just "Save". Also, I would do it in as few steps as possible.

I cannot give you figures to use as I do not know the proper size of your original file. To get this, you would open it in Photoshop and then do "Image Size". You would then record the Image width and height in pixels, and then the Document Size, width and height in inches, and Resolution in pixels/inch.

When you are ready to resample the image, you change the Document Size parameters, starting with only the width and height in inches. Leave the original pixels/inch, then "Save As" the file at Quality 12. (New verb, Save As.)

Progressively change the pixels/inch and "Save As" again until the file size on disk is 5MB.

If you need more explanation let me know.

Am.

[Speedway]

This sounds like the printer I use (Photo Enlargements) and I am more than happy with their 12X18 prints. I had 36 done on a Christmas special at the bargain price of $1.00 each, all the images were all uploaded at under 3MB which is what they ask for for the best workflow. Too many large files sent in one email can cause server problems and faults. I have also used them for 6x4 go kart pics where I have got over 250 in one order for 10 cents each, this is cheaper than I can buy the paper for, the quality has always been excellent and the turnaround of 4 working days is excellent as I live in a remote area. The average file dimenentions I send for 12X18 prints are 4096x2731, 72dpi, 2.5-3 MB.
Keith.