Ask Tim Grey Save JPEG as TIFF/PSD?

Ask Tim Grey eNewsletter, December 17, 2009, Learn more at www.timgrey.com

Today's Question:
I received the photographer’s files from my daughter’s wedding. They are all JPEG in reasonably large files (5-7 Mb). Is there an advantage to converting them to TIFF or PSD if I need to do minor editing (enlarge/reduce, some color correction) before making prints for the family?

Tim's Answer:
There is some advantage, but it is largely theoretical and it assumes what I think of as a "typical" approach to touching up the image. Specifically, if you actually apply changes and then re-save the files as JPEG images, then JPEG compression will be applied to the image. That means compression was applied once when the image was originally saved as a JPEG (either during capture if the photographer captured in JPEG mode or after converting if the images had been captured in RAW), and then again when you re-save the image after applying your adjustments.

However, assuming your adjustments are indeed relatively minor and that you only save them again once, the difference will be truly minor, to the extent that nobody would be able to see any difference in the final print. Even with a magnifying glass. So as long as you keep your adjustments minor you can feel comfortable keeping the images in JPEG mode, using the maximum Quality setting of 12 when you do re-save he final result for each image as a JPEG.
If you're going to do any extensive work on the images, I would naturally recommend working with adjustment layers or other layers as needed in order to apply the changes, and then save the resulting file with all layers intact as either a TIFF or PSD file. You can always use that file as the basis for other output, such as printing directly, or saving that master image as a JPEG as needed for specific purposes (for example, sharing via email).

There's no question the absolute best approach to optimizing any image (from the perspective of flexibility and ultimate image quality) is to utilize a layer-based non-destructive workflow (such as through the use of adjustment layers, as covered on my DVD, "Photoshop Hands-On: Adjustments", available through my online store at www.timgrey.com/store/). However, when appropriate caution is taken you can still produce excellent images while keeping those images in the JPEG file format. It is similar to the fact that you'll improve flexibility and image quality by capturing in RAW, but can still produce excellent images capturing in JPEG mode.

I might add that even though the photographer presumably has a copy of the original captures, you should also be sure to make a backup copy (ideally more than one) of these important images.

Become a Member
The Ask Tim Grey eNewsletter is free to receive, but paid Ask Tim Grey Members receive special benefits, including:
Opportunity to submit questions to be considered for inclusion in the Ask Tim Grey eNewsletter.
Discounts and special offers available only to Members.
Access to the full archive of previous emails (going back over eight years) with search capability.
The knowledge you are supporting this valuable service.
Much more!
Details on becoming a member can be found here:www.timgrey.com/asktimgrey/

FYI, Tim has said that as long as his DDQ's are passed along in their entirety they can be distributed to others