jpegs

[jomar]

Hi guys,
I have been shooting only jpegs and sending out for printing on silver halide.
The images are so sharp it hurts, I mainly work in 2 sizes 10"x15" and 20" x30".
I would like to know why everyone is shooting tiff and raw and having to deal with these extra large file sizes,when the jpeg quality is so spectacular. I do a lot of Landscape work for gallaries and I apprieciate having the extra number of exposures capacity.
I have only used photoshop 3 times to tidy up some dust that got onto ccd.
My priority is to keep shooting images in prefrance to being on the computer.
Am I missing out on something important?
I work with the lab and after they have done a post card size print I nominate the color corrections to apply before the enlargemnts are printed.
Looking forward to hearing why tiff and raw are your prefrences.
Thanks
Joe

[X-Sync]

Hi Jomar,

I agree that the quality from JPEG is superb, and with little or no adjustment it can be output at very impressive size to quality ratio. But to answer your question on as to why I still use RAW is simple; many of the people I submit work to still think of digital in terms of scanned transparencies, therefore insisting on large file sizes. A 12MP JPEG from the S2 will print at A3 no problems, and by virtue of the fact that there is no grain, the print looks clean and pretty damn impressive. Try telling that to the picture library and the publishers who insist on 20MB. 35MB and one who only excepts work 50MB and upwards.

Happy Shooting

Simon

[jomar]

Thanks Simon,
So I take it stock libraryries and publishers are slowly getting educated?.
I have thoughts of publishing a tourist book with A4 size pictures,and a run of poster's 20"x30", am I going to get the quality from a printing house as I have enjoyed from my silver halides from my jpeg's @12MP.
Thanks
Joe

[Wichita Wayne]

The situation needs the added flexability of the RAW format. Gary Fong also recommends JPEG. He claims that the S2 was engineered to produce the highest quality JPEGs available and that we should all take advantage of this. Since I read his explination I switched back to JPEG and have had good results with much more storage area on my microdrive.

[bjnicholls]

Raw gives you the ability to modify your image output when your camera settings aren't optimal. You can't rely on the LCD to show you the exposure, especially if you're not using the histogram. Shooting raw gives you the critical 1/3 stop exposure adjustment capability the camera lacks. It will deliver a 16 bit image that will hold up to image editing without creating a sawtooth histogram and the stairstep tones that the same moves could create in an 8 bit file.

The notion that the cpu in the camera can create a better jpeg from the raw CCD data than is possible using the same data via a powerful computer strikes me as just plain silly.

[jomar]

Thanks Wayne,
I was getting a bit concerned that I had been out of step.
As I shoot carefully I only intend to be using photoshop when things may have gone wrong, so sticking with the jpeg seems a sound method.

I take it Gary Fong is "The EXpert" ?. I'm in Australia and have not seen anything from him, does he have site, book ?

I have a couple of questions to further help clarify my knowledge.

If a jpeg file is renamed(making no images changes in photoshop)does any loss of quality occur?

Making changes to jpeg file in photoshop and then saving as tiff to avoid compression, does this mean the tiff is as good as the original jpeg quality?

Looking forward to the feed back.
Joe

[MikePL]

Huh, I've been dealing with jpegs for many years, so I might clarify some things.

If you rename the file without opening it, no data loss occurs. However, if you open it in Photoshop and do nothing but press ctrl+s (to save it, for those unfamiliar with shortcuts) you will have data loss.

The best way to retain image quality is to convert to TIF once the images are downloaded onto the computer, and later work on those TIFs as much as you want.

If you plan to save pictures for the web, the best setting is no. 7 in Photoshop. There must be something with compression algorithms which creates an awckward situation: setting 7 has a better quality that setting 6 but has a smaller file size (strange...).

As to giving jpegs for magazines and prints, this is a tough situation. Over two thirds of people working there have no idea of image quality. They are 'TIFF-narrow-minded'. The jpg's from the S2 have very little artifacts and are great, no matter the print size and purpose. What I do is just change the jpg's into Tiff and give them that way. All the magazine gurus say: woooow, your Tiffs are great, we'll work with you.

That's the way to go with magazines: convert jpg to tif and nobody will notice.

As a side note, I must say that this magazine staff seems a bit retarded. They have also problems with dpi vs. pixels vs. measurements. They don't seem to understand that only the physical number of pixels determines image quality. From that, you can create various dpi/size combinations. If you bring a 1600x1200 file converted into 100dpi, they say that it's crap. If you take a 800x600 file and put 300dpi (via Photoshop) they are pleased as hell. Nobody looks at pixel size, they just check dpi and are happy, LOL.

They don't know either that in the print industry they deal with raster graphics and not continuous-tone. So every colour is represented by a group of dots. This means that you can actually decrease the image size 2 or 3 times and there will still be no quality difference.

Seems like I have messed everything up instead of claryfing, but the mentioned issues are really controversial and misunderstood by lots of people from the press/photo industry.

[jomar]

Thank you Mike, your explanations along with the others have been excellent feed back.

Mike just to further clarify renaming a jpeg file... I open the folder as thumbnails.
The file name of each picture appears as a number below the thumbnail.
I currently click once on this once, highlighting the thumbnail and current file name.
Then I rename.
I assume that the same situation of "no loss of data occurs" ie, the fact that it is open as a thumbnail has no effect?
Looking forward to your reply.
Joe

[MikePL]

There is no data loss during such kind of renaming. Image viewers (e.g. ACDsee) just present the image, therefore you cannot alter it in any way. Renaming does not intrude into the jpeg data either. You can even open the picture in Photoshop (or similar), and if you close it without saving, there will be no data loss. But once you make a 'save' (ctrl+s) or 'save as' (ctrl+shift+s) you will have data loss. So make sure that whatever renaming or copying you make, do it in an image viewer, not an image editor.

Don't worry about thumbnails, they are just open images, downsized to become a thumbnail. No alteration occurs.

[CaptJR]

Mike
You seem to know quite a bit about jpg files. When I make adjustments to a jpg file, I always use the 12 quality in Photoshop. Everything else the same (number of pixels, etc.) that is the setting which increases file size, hoping to retain as much image quality as posible. Any thoughts?
Thank you
JR

P.S. I also don't really know anything about the format options, Baseline (Standard), Baseline (Optimized), Progressive.

Sorry about the P.S. while typing I thought to go to the Help tab in Photoshop. Here is what it says.

Baseline ("Standard") - to use a format recognizable to most Web browsers.

Baseline (Optimized) - to optimize the color quality of the image and produce a slightly smaller file size. This option is not supported by all Web browsers.

Progressive - to create an image that displays gradually as it is downloaded--in a series of scans (you specify how many) showing increasingly detailed versions of the entire image. Progressive JPEG images files are slightly larger in size, require more RAM for viewing, and are not supported by all applications and Web browsers.

According to this, maybe I should be using Optimized, except when prepairing a web picture.
JR