Reconstituting an emailed EPS file

ktg222 · #1 02-27-2008, 01:46 PM

I posted this on another forum but got little response. I thought I would try here.

A reputable photo studio in my area who does all the photography for a national magazine has an interesting way to sent files back and for from his studio to his client; and visa versa. He shoots a 1Ds MkII.

Apparently, he takes a tiff file and saves it as an EPS file in the High Quality JPEG mode. He emails the file to the client. The file is small so it is easy to send via email. The client, once receiving the file, opens the EPS file in Photoshop and saves as a full tiff, or a PSD file.

What do you think of this method? Is he really just saving a high level jpeg and just changing the format on the other end? There must be compression involved of course. What are the quality issues?

I did a test and the EPS file is 3.24 MB once saved from a tiff or PSD. It was then emailed normally and then re-opened in Photoshop, saved as a PSD, and the size was 43.67 MB.

Comments?

k

Swampy · #2 02-27-2008, 01:54 PM

Interesting, K. The only time I ever save as EPS is when there is transparency involved. Never thought of saving for file size.

ktg222 · #3 02-27-2008, 02:59 PM

Dee,

This is interesting. This photographer has been doing this for years. If I mentioned the publication you would know it. Someone here will know the answer. I suspect that all that is being done is a simple conversion to a hi rez jpeg. What the EPS feature does I'm not sure.

byRo? Doug?

k

Damo77 · #4 02-27-2008, 03:45 PM

Yes, it seems like bunkum to me. Jpeg compression is jpeg compression, whether it's hidden in an EPS or not.

I didn't think anyone used EPSs any more. They're pretty much a relic now.

Doug Nelson · #5 02-27-2008, 04:02 PM

Yeah, what Damien said. It's just a JPG in a wrapper.

I run into a lot of old-school Macites that still feel EPS is some sort of magic voodoo file format. And I can appreciate why they came to feel that way, since Macs handled EPS natively, and EPS was built to be able to contain just about any other file format.

EPS has evolved into PDF, and the new Macs still handle PDFs natively. But as far as graphic files go, it's still just a wrapper.

ktg222 · #6 02-27-2008, 05:16 PM

That seems to make sense, Doug. But why then when you save that EPS file as a tiff or a PSD does the file size jump to a 43 MB file from the EPS/jpeg file of 3.4 MB?

k

Swampy · #7 02-27-2008, 05:21 PM

Damo:

>>>I didn't think anyone used EPSs any more. They're pretty much a relic now.

It may be a "relic" in the world of digital images, but still in use every day for vector files.

Damo77 · #8 02-27-2008, 05:36 PM

Ha ha! Yeah, of course, so do I. I just meant for raster images.

Damo77 · #9 02-27-2008, 05:37 PM

Quote:

Originally Posted by ktg222

That seems to make sense, Doug. But why then when you save that EPS file as a tiff or a PSD does the file size jump to a 43 MB file from the EPS/jpeg file of 3.4 MB?

Well, it's simply decompressing it back to its original size.

ktg222 · #10 02-27-2008, 05:46 PM

Damo,

So in the initial EPS/jpeg conversion and the re-saving as a tiff (where the file size jumps back to a 43 meg file) there should/would be some degridation, yes? I can't see any.

k

Damo77 · #11 02-27-2008, 05:51 PM

Yes, I would expect to see some.

AdamZx3 · #12 02-29-2008, 10:56 AM

ktg222,

The EPS is an encapsulated postscript file, basically like a postscript file without page numbers etc.. The only reason to use .eps is if he had vector images or type in the photo, then it would save those without rasterizing them, and they would print as vectors, while the photo would still be a jpeg.

When I open up a 1ds-mkII jpg it jumps to 47.5 mb when the jpeg is only a few mb.

The best thing to do is have him convert the CR2 raw's into a dng with lossless compression, this will take it down to 12mb, which should be very do-able in email. You can also FTP them if you have a lot to transfer.

Otherwise save the step and save to a high quality jpg, and compress with winzip or winrar.

byRo · #13 02-29-2008, 03:47 PM

Quote:

Originally Posted by ktg222

byRo? Doug?

Sorry I'm a bit late and, of course, the matter has been cleared up.

Just to add a comment....

I think the guys from the Joint Photographics Expert Group deserve a bit more respect here.
They got together the best experts on image compression and studied every aspect of the subject for six years, issuing a standard that has been adopted world-wide.
There are certainly some schemes that will compress slightly better, but the trade-in cost of incompatability just isn't worth it. (Not even JPEG 2000 caught on).

If someone tells you there's a wonderful new compression technique for rasterized photographic images - think twice.

Rô

pixelzombie · #14 02-29-2008, 05:30 PM

Quote:

Originally Posted by Damo77

Yes, it seems like bunkum to me. Jpeg compression is jpeg compression, whether it's hidden in an EPS or not.

I didn't think anyone used EPSs any more. They're pretty much a relic now.

you still have to use them with spot colors as not every rip can deal with a psd file with spot channels and/or deal with transparency...