You might want to try using "Save for Web & Devices" in PS to save your Jpeg if you aren't already. You may get a warning when you try to do it if the image is large but it usually works OK for me anyway. The advantage of SfW&D is that you have all the controls right there for what you are trying to do: resolution/pixel size, Jpeg quality, etc.. You also have quality comparison preview windows that you can use and it will calculate an estimated final Jpeg size for you.
A possible work flow would be:
- With your image active in PS, select Save for Web & Devices.
- Use the Jpeg quality parameter to check initial quality and get a feel for the possible file size. You can also use the 2-up and 4-up preview windows to compare quality settings.
- If quality degrades too much before you reach your target file size, then use the Image Size parameters to start reducing pixel size. There is a handy percentage field that will reduce or enlarge proportionally, retaining your crop ratio. Once you change the Image Size parameters, you will need to click on the preview to calculate the new estimated file size. You can even up-rez using this method.
There are other parameters for controlling the embedding of the color profile and metadata. Not embedding the color profile usually saves you about 4k, which really isn't much. It's usually worth embedding the color profile to remove all doubt as to what color profile was used.
Dennis: Thank you. I'll play around with the 'Save for Web & Devices' option and see how that works. Sounds like it has potential, and I appreciate the suggestion.
Do you want highest resolution or highest quality. At the extremes there is a trade-off between resolution and compression in a jpg file. Too much compression will ruin a high-res file and too little resolution will not save a low-compression file.
You can set resolution with the final display/print size in mind or you give them everything and let them sort it out. Most monitors display 100 pixels per inch and most prints want about 300 ppi (give or take) and so right there you have a problem of optimizing for one and not the other with a single file.
Russ Isabella wrote:
I'm either over- or under-thinking this and I need some help to figure out which it is.
My goal is to have the highest resolution image file possible given the constraints I must work within.
The constraints:
final images must be in jpg format
final size must be between 1-1.5 MB
working from RAW files
cropping in Adobe Camera Raw
Here's what I'm doing and I'd like to know if there's a better way:
Open RAW fie in ACR
crop using ratio (rather than a specific metric)
open cropped image in photoshop
after minor editing, save as jpg
in process of saving, alter quality (file size) to achieve required size
Any insights would be appreciated. Thanks!...Show more →
I'm going to presume those were constraints handed to you by someone else who doesn't know any better--specifically, that "file size" requirement.
Given that, let's figure out what you really need to provide them for best quality and how to make it look like it fits their constraints. You're most likely correct in leaving the file size adjustment to the end of the process, although adjusting quality might not be the best way to do it.
What is this for? What will be the final display medium? Final display dimensions?
