Size matters

I sometimes enter a photo competition where part of the criteria are that the image is no bigger than 1024 by 768 and no larger than 200kb. I find it impossible to generate a jpeg of those dimensions and that size without some serious (and probably detrimental) compression. I end up submitting a jpeg of about 780 pixels wide and about 68% compression.

What do people think regarding dimensions v. size? Is it better to have a 1024x768 image compressed by 50% or a smaller image but less compression?

Thanks, Kris.

Those sizes sound like the images are meant for projection, 1024x768 has been a standard amongst Photography Clubs for quite some time now, things are progressing to larger sizes though with the availability of higher resolution projectors.

As for the size of the file I dont think it really matters a great deal, I have resized to 1024x768 for club competitions and have saved at various file sizes, the Blue Tit in my PPG is only about 60kb and the Chaffinch is about 104kb, both these were resized for the PPG from 1024x768 files that had been in club competitions.

If you are entering a competition then the biggest criterion is to follow the instructions. Otherwise you risk your image being rejected.

1024x768 and around 200-300K is fine for projection or screen viewing. I wouldn't use a smaller image as, even if it's allowed, it will compromise the quality against the other entries.

A limit of 200K is a bit mean for complex images, but the rules are the rules.

All you ever wanted to know about jpeg: http://photo.net/learn/jpeg/

What program are you using Kris? Different programs use different numbering for jpeg compression. IIRC older versions of Photoshop used 1-12. CS5 uses 1-99 though.

PS despite usually being in the 1-99 range it's not actually a percentage.

Lightroom has an option where you set output resolution and size and it encodes it the best it can. I've used it a couple of times and use it for PPG submissions.

Just be aware there is a bug in LR 3.2 related to the 'limit file size' option. It will strip your exif! Supposedly this is a 'feature', but I've always believed in calling a spade a spade link. I think this was changed back in 3.3, but I have yet to upgrade.

There is also a memory leak issue with 'limit file size': http://forums.adobe.com/thread/801189?tstart=0

LOL Didn't know that but am on 3.4RC anyway.

The website will reject the image if it doesn't meet those criteria.

I am using Lightroom 1.4 which has the resize option and uses a compression scale of 1-100 but doesn't have a max filesize option. To get a 1024x768 image I have to use a compression of 61.

K.

In photoshop if you use save for web then the setting high quality means a compresion of 60% that should be enough to bring it down the 200kb depending the photo.

here is a comparison in the middle you can select differnt compresion while looking at the photo at 200% zoom http://www.cambridgeincolour.com/tutorials/imagetypes.htm

As you can see 60% still has a lot of quality.

It's better to have the most amount of pixels, if you know the displaying device then native pixels is even better if the computer will need to resize the photo again as well it's a lost of quality.

I mostly use 1024x768 for web and quick "showcasing" most display devices like beamers have this resolution natively and almost all monitors should be able to view it without resizing.

In photoshop it can give you an estimated file size as well (elements 2-9 and CS2)

Do you have elements? You could always export a large file and then get it right using the save feature in that program.

3.4 ??

I was looking for 3.4 the other day but couldn't find one. Cool. trots off to adobe

It is a release candidate, so not a final version. Seems good so far. DPReview have a link on their news article.