Alamy file sizes...??

[PEACHMAN]

While registering with Alamy I see the file size requirement is minimum of 48 mb uncompressed and 25 mb compressed...I don't think I have ever produced a file of this size....most are more like 3 to 4 mb...Am I looking at this mistakenly ??

[Box Brownie]

While registering with Alamy I see the file size requirement is minimum of 48 mb uncompressed and 25 mb compressed...I don't think I have ever produced a file of this size....most are more like 3 to 4 mb...Am I looking at this mistakenly ??

Hi

I suggest you make a coffee or grab a beer and read throught this thread here http://photography-on-the.net/forum/showthread.php?t=559642 the subject of Alamy and file sizes I was mentioned/discussed/picked apart etc at intervals through it.

HTH :)

[jbimages]

While registering with Alamy I see the file size requirement is minimum of 48 mb uncompressed and 25 mb compressed...I don't think I have ever produced a file of this size....most are more like 3 to 4 mb...Am I looking at this mistakenly ??


Yes you are!.
Its a minimum file size of 48MB uncompressed and a maximum compressed file size of 25MB.

What's not immediately apparent is that they are talking about different files. The first is the size of the uncompressed file as shown in photoshop, or calculated from the number of pixels in the image, the second is the maximum size of the jpg compressed file on your hard disk.

[PEACHMAN]

Hey, thanks folks...I don't know if I have it correct now, but I do see it's not just out of PS jpg... I have gone in and set the resolution higher, converted to tiff and easily brought the uncompressed files to 50mb...so I'm hoping this will work !!

[jbimages]

That's got a more than even chance of not working.

Are you working with an out of camera jpg or RAW, or have you upressed it?

[PEACHMAN]

Not working ?? as in not acceptable to Alamy?? I am using jpg...:confused: (upressed ?)

[gary88]

Not working ?? as in not acceptable to Alamy?? I am using jpg...:confused: (upressed ?)

Converting to JPEG should be the absolute last thing you do. While working with the image, you should be using a 16bit TIFF the entire time.

Check out this thread:

http://photography-on-the.net/forum/showthread.php?t=559642

[PEACHMAN]

I'm beginning to think my 8 billion jpg photos are useless ??

[Dennis_Hammer]

I'm beginning to think my 8 billion jpg photos are useless ??

For Alamy they might be. Best to shoot for the mind. Then submit to them, besides being picky about pic sizes they are a little picky about an assortment of other things also.

[jbimages]

I'm beginning to think my 8 billion jpg photos are useless ??

Are these out of the camera jpgs?

I see you have a 300D and a 20D. The 300D is at the low end of the size range, My 300D photos on Alamy were all upsized from a 16 bit TIF, created from a RAW file, and at the minimum image size for acceptance. The out of camera jpg ones I looked at after upsizing showed noticeable artifacts so I didn't persist with them.
You might have a better chance with the 8.2MP files from the 20D. I have no problems with the files from my 30D, but then I always start with a RAW file.

[photoguy6405]

FWIW: I've had older files from my 10D accepted just fine, most not RAW but jpegs, but I've had a few rejected also. I find that my 10D files have to be super good to be accepted.

[Matthew.Samos]

Not to hijack this thread, but I've got a similar question..
This is my Alamy optimization process:
> Upload RAW from camera into Aperture
> Minor post-processing
> Open image(s) into PS from Aperture, which converts them to .TIFF
> Go to Image Size and change file to 48MB+ with Bicubic Smoothing
> Go to Mode and select 8-bit
> Save As .JPG

But this doesn't seem to work. My question is: Should I be selecting 8-bit before enlarging the image? It seems logical to me, as the change to 8-bit knocks the size down by almost 50% (22MB)...but on the other hand, I was under the impression that the enlargement should be done before the image resolution is diminished at all. Is there something I'm missing? Also, I'm not using the best of cameras...to say the least. Pentax *ist DL, hopefully not for too much longer. 6.1MP is a pain.

By the way, I just joined the forum today. Just decided to submit to Alamy as well. I've got so much to learn.

[gary88]

Upsizing is the first thing you should do when opening up an image in PS (or converting to 16bit if it isn't already). Then after all is done you change the image to 8bit and save as a high quality JPEG as your last two steps.

and welcome to the forum!

[Matthew.Samos]

Right...I'm pretty sure that's what I've been doing. My process seems to be identical to what you've described here and in the aforementioned thread. Yet, as soon as I hit 8-bit, I lose half of my file size. Am I supposed to be upsizing considerably beyond 48Mb to compensate for the size loss when the image goes from 16-bit to 8-bit?

Just to recap-- I usually start with 35Mbish 16-bit .TIFF in PS, upsize it to 48Mb+, then change to 8-bit, which effectively reduces the image to around 22Mb before I can save as a high quality JPEG. Sorry if I'm just being dense here. Where am I going wrong?

[Matthew.Samos]

Think I may have figured it out. It seems like you do have to overcompensate with the initial upsizing so it ends up around 48 when you change to 8-bit. Let me know if that sounds wrong.

[jbimages]

If each pixel is 16 bits wide, you only need half as many to make 48MB than you would if they are 8 bits wide.

[Webby]

if you are up-sizing in 16 bit mode, then the file size needs to be 96mb minimum. Then when you convert back to 8 bit, the file size will drop to 48mb. Generally, if you make your longest side 5120 pixels, then you will get a 100mb file. Converting to 8 bit drops it to 50mb. Save as tiff - drops to 7-10mb for uploading
Webby

[Matthew.Samos]

Thanks for the input guys. Now I need to learn to take sharper photos.