Yep - that's the bit that confused me.
Cheers for the mention of the forum - went and found this.
Our required file size for submitting Jpegs seems to cause an incomprehensible amount of confusion with a high volume of photographers. Put simply, we are flabbergasted as to how many times we are asked, daily, of what format and size of images we require!
Let’s set the record straight right now. First and foremost, yes, we want you to send Jpegs. No, we don’t want you to send Tiffs.
The reason for this is that we provide our clients with Jpegs to download, not Tiffs. It’s been industry standard to work like this for a long time now and even in the days when we required you to send us Tiffs, we converted them to Jpeg for the clients. Yes we know Jpeg is a lossy format, but to the naked eye, there is no visible difference between a high quality Jpeg and a Tiff file. The client can simply download the Jpeg, save it as a Tiff, and work away on it saving as many times as they like without loss in quality. It’s really that simple!
Now that’s out of the way let’s move onto file size. Jpeg is a compressed file format. The compressed file size (size on disk) varies with picture content and should generally be ignored, as long as it’s no bigger than 25MB, which is our upper limit for Jpeg size. What’s important is the uncompressed (opened) file size. The opened file must be at least 24MB at 8 bit to get through our quality control. Typically a 24MB 8 bit Tiff file will be between 2MB and 5MB as a Jpeg if your image was shot digitally. Film scans will be larger. This is because Jpeg “sees” film grain as image detail and compresses it too. Remember, we do not want a Jpeg 24MB in size as that would be ridiculously large when uncompressed (opened)!
One thing you don’t want to do is work on your images whilst they are in Jpeg form, repeatedly saving as you go along. Saving a Jpeg as a Jpeg is pretty much a no no, as you are recompressing an already compressed file.
Now there are various ways of doing this, but an ideal workflow example for creating the required file size would be:
* Convert your image into an 8 bit Tiff file (save as, Tiff)
* In an image editing program such as Photoshop, upsize the image to a minimum of 24MB (if you need to).
* Make any alterations as needed, inspect the image carefully at 100%
* At the very last step save your image as a Jpeg and send us that Jpeg. Remember, the Jpeg is the compressed size so this will typically be between 2MB-5MB
There are a handful of digital cameras on the market that produce native uncompressed file sizes above 24MB so you will not need to do the above for those. The same goes for film scans.
Remember to also inspect your images carefully in accordance with our submission guidelines, found here: