Compression

[steve@thaib]

Reading the blurb from a stock library yesterday I was struck by the file sizes they use, minimum 48mb. If I shoot RAW files they come out at 6mb, convert it to JPG and it's 3.5, TIFF is around 16mb. Am I missing something here?

[ElectrO]

If films were not compressed to DVD, they would be over 100 times bigger.

HD video could consume as much as 9.6 gigabytes per minute

E

[steve@thaib]

So is that what I'm seeing? Everything is compressed? If that is the case then how big is a 6mb RAW file in the real world?

[syeatman]

Originally Posted by steve@thaib

So is that what I'm seeing? Everything is compressed? If that is the case then how big is a 6mb RAW file in the real world?

A 6MB RAW file is a 6MB RAW file, the data from the sensors wrapped up in a proprietary format.

I'm presuming that you are talking about images that were shot on film and scanned, that's why they are so large. 48MB is not actually that big, I think they can be 60-70MB.

Also, for digital I have read an article (that I am yet to find again!) that mentioned resampling digital images to make them up to the size that magazines/libraries want. PS will resample for you - just go to Image Size and there is an option for resampling that allows you to increase the image size

[steve@thaib]

I found it odd because it was specifically digital, but it also said that a 6mp camera would give images of that size and I thought I was coming to understand file sizes.

[erik1]

Originally Posted by steve@thaib

I found it odd because it was specifically digital, but it also said that a 6mp camera would give images of that size and I thought I was coming to understand file sizes.

Steve:

most are drumscans of middleformat positivs and nowadays we also have the digitalbacks that go up to 22-48 MP so filesizes round 50 Mb are rather normal. especially the drumscans can be even higher

[syeatman]

Originally Posted by erik1

Steve:

most are drumscans of middleformat positivs and nowadays we also have the digitalbacks that go up to 22-48 MP so filesizes round 50 Mb are rather normal. especially the drumscans can be even higher

Of course, didn't think about medium format. thankfully somone knows what they are talking about.

[steve@thaib]

Hells teeth Erik! I think I understand 3 or 4 words there! Are you seriously saying that you are shooting almost 50mb pictures?

What do you use to process files that big? I have to be patient while my PC converts a 6mb RAW file.

[ElectrO]

RAW/Uncompressed files suck so much from your computer. I do hope you have a Dual Processor when people are manipulating files of that size in video/picture format.

E

[syeatman]

Originally Posted by ElectrO

RAW/Uncompressed files suck so much from your computer. I do hope you have a Dual Processor when people are manipulating files of that size in video/picture format.

E

I post-process my RAW files on my laptop and don't really have any problems. Converting them to 8-bit on PS helps a bit too.

[steve@thaib]

I can do the same without too much of an issue, but when I export from the Nikon Capture software it takes a couple of minutes to process a 6meg file, a 50 meg file does not bear thinking about.