Expert: Kevin Stohlmeyer - 2/12/2010

Question
QUESTION: I took a photo using my point and shoot camera. The size of that photo(JPEG) was about 2.17MB. After editing the photo (such as blurring the background, sharpening it using the unsharp mask) using Photoshop CS2 and saving it in JPEG the size fell to 520 KB. I did select the high quality setting while saving. I did notice this drastic fall in size happen to a few of my other photos after editing it using photoshop. Most of them were above 1.8 MB.

Why was this particular photo compressed this much? I don't think I can barely print 4X6 with that file size; let alone a full A4. Also I have noticed in the JPEG option while saving, under size, 56.6 Kbps. What does that mean?

ANSWER: Hi Jigishu,


Did you crop this photo at all or accidentally change the size or resolution somehow? The crop tool has a nasty little option to change resolution when you crop and if it was used, can change your size dramatically.

Otherwise, I always use the maximum setting for quality in a JPG (12) anything less will change the size as well.

The Kbps is Kilobytes per second. Its a term used for uploading or viewing on the web.


Thanks

Kevin


---------- FOLLOW-UP ----------

QUESTION: I did not crop the photo. I do not however know the way of changing the resolution in Photoshop. I have right clicked the photo from the windows explorer and went to properties. The resolution of the edited photo is 3264 X 2448 (same as the original one).

I have always saved my photos using the high setting (8) and the format option was baseline (standard). I don't remember changing any settings from default.

I knew that saving in my method would decreas the filesize a little bit but not by almost 2MB! The strange thing is in my other edited photos the file size didn't decrease that much.

I tried saving it in maximum quality and the filesize increased to 2.11MB.

Answer
Hi Jigishu,

Have you gone into the different shots and checked their settings under Image>Image size? Im betting that they are set differently somehow - either size or resolution, hence the different sizes. Checking the size under windows explorer is not a good way to compare sizes.


Thanks


Kevin