I have people sending me photos to edit. I work a little in photoshop cs4 and then back in lightroom 3, but when I go to send them the photos back ,they are HUGE! How can I send them the same size file they sent me? (the ones I am currently working on are tiff. files.)
Obviously if you have made significant edits and/ or added layers to a TIFF file it will be larger, it may also have been an 8 bit file originally (not a good idea for editing) and you have saved as a 16 bit. Also the file may have been compressed when it was sent and you have applied no compression if you have just exported at original size. Tiff compression is lossless and can reduce the size of the un opened file considerably. The opened file size is dependent on the size in pixels of the image, whether there are layers and whether the file is in 8 bit of 16 bit format.
So how do I find out the file size of the original?
I just want to make sure the quality of the photo is not less then what it was when they sent it. I just don't really understand how to do that.
If it will be bigger with my edits then how will I ever know if they are getting back the same printing quality than they sent??
If you are editing tif files, then you have only a couple of choices.
Flatten the image before you save it. This will reduce it down to one layer. That's the smallest you can get.
When you first open the image, look to see if it's 8 bit or 16 bit tif. It won't help you, but if the image is 8 bit, and you save it as 16 bit, you will have dramatically increased the size of the file for nothing. If it's started as 16, no worries!
check if you are saving with compression. Tif compression is lossless, so unless you did something like resize+resample, it remains the same bit density, etc, so should be just as printable as what they sent you (unless you messed up!).
Ask the person who sent you the file. Open one in PS or any other bitmap editor and check. If using windows (there is also a way in OSX but can't remember it right now...some one will pop up and say) right click on the file in explorer (you can do this from LR by right clicking on the image and selecting show in explorer), select properties, details and then look for the bit depth. 24 means an 8 bit RGB file, such as a jpeg. 8 bits is the usual for PNG or Giff. A DNG file or Tiff will have 48 if saved as a 16 bit file.