Resizing a raw file and keeping it raw.

[jenne1978]

I know what you might be thinking, but I dont want to know how to resize an image. I want to know how I can get a raw file smaller while keeping it raw. I don't want to convert it to pixels. Is this even possible?

[John 2]

I know of no way to reduce an image in size and re-saving it in the original manufacturer's RAW format (other than by cropping it). Others on the forum might. However in Photoshop, if you open your image in the RAW converter and then open it immediately in PS using "Open Image" (CS6 in my case), and then down size it, there is a save option to save it in what is described as "Photoshop RAW". I have never used this and know nothing about it but it presumably has the characteristics of a RAW file albeit in a different format.

[James G]

Jenne, I don't know what camera you are using, but I shoot with a Canon 7d. I do have an option to capture raw as full size , medium or small, although I must admit I have never had it on anything other than full size since I got it.

I do not know of any way of resizing once capture is achieved.

[Stagecoach]

Jenne,

I tried using WinZip and could only reduce a 19 meg Raw file down to 15 meg.

[Macmahon]

I know what you might thinking, but I dont want to know how to how to resize an image. I want to know how I can get a raw file smaller while keeping it raw. I don't want to convert it to pixels. Is this even possible?

I've never heard of a way, nor have I ever wanted to do it. May I ask why you want to decrease your raw file size?

Tim

[John 2]

Googled your problem and found this so ignore my previous input.

"Photoshop RAW is not the same as camera raw. The Photoshop .raw file format available under the Save As... menu saves as a headerless TIFF file, usable only in very specialized circumstances. Even Photoshop cannot read a Photoshop .raw file.

However, you can convert any JPG or TIF file into a DNG via Adobe Camera Raw. But it defeats most of the advantages of an actual raw file."

[NigelD]

What would you hope to gain by doing this - perhaps if we knew that we could suggest something to help. If it's a question of storage, then external HD's are cheap nowadays so you would be able to keep all your files intact and not have to worry about duplicating big RAW files and slightly smaller ones. You would have to re-label/rename stuff as well so more time consuming.

[jenne1978]

I need it for a course. So filesize is an issue. I know workarounds, but for now I would like to stay on topic.

[davidedric]

Hi Jenne,

I'm not an expert, but from my understanding of the nature of a RAW file, what you are asking doesn't seem logically possible, or at least logically feasible. Creating a RAW file from the sensor data is a complex, and proprietary, process. It seems to me that you would have to reverse engineer the RAW file that you have back to some more primitive form, then manipulate that to a smaller image, then re-apply some form of RAW creation. I just can't see why anyone would have ever taken the trouble to develop such software, and I doubt it is an amateur coder's job.

[nimitzbenedicto]

I need it for a course. So filesize is an issue. I know workarounds, but for now I would like to stay on topic.

I think John 2 mentioned it, converting to DNG may be it.
i.e. reducing file size but not losing too much info.

HTH

[benm]

Some one suggested zipping the file. If you are shooting uncompressed RAW you can get some reduction in size (Stagecoach got about 20%). If you are shooting compressed RAW (an option on some Nikons) there will be no benefit to zipping; it is already as small as possible.

Some cameras (for example, Canon) have a "small RAW" feature but you need to set that before shooting.

Why do you want to reduce the file size?

[xpatUSA]

Hi Jenne,

Are you going to tell us what camera you are using?

I too have a camera (Sigma) that takes 3 different sizes of RAW file. Not surprisingly, the small (half-size) file takes about a quarter of the disk space.

Do you have a full-frame camera with an APS-C (small lenses) mode on it? That would give smaller files I guess, because it uses a smaller part of the sensor. Does you camera have something called "binning mode"? That would do it too, if it's true binning.

How about buying a cheap "low" MPx count older camera, just for the course, then re-sell? For example, my 3MP Sigma churns out 9MP raw files full-size and 2MP half-size.

[dje]

In Adobe Camera Raw (ACR), and possibly Lightroom, there is an option to Save As DNG. Under this option, there is a further option to use lossy compression, with or without re-sizing the number of pixels. I don't know what sort of compression is used and I don't know what you can do with the dng after that but presumably you can edit it like any other dng.

Might be worth a look.

Dave

[DanK]

It's not clear what you mean. Why don't you ask the instructor for clarification?

[rpcrowe]

I cannot understand the reason that the instructor would want you to transmit a RAW file... To tell you the truth, I would not place much stock in that instructor's instructional techniques... The least I would do if I were you is ask for clarification of why the instructor wants you to transmit a RAW file which isn't yet an image and how he/she wishes you to transmit the file.

[xpatUSA]

... The least I would do if I were you is ask for clarification of why the instructor wants you to transmit a RAW file which isn't yet an image and how he/she wishes you to transmit the file.

+1 to that. And, just for grins, send a 48MB Sigma Merrill X3F file, supported by only a few apps on the planet, not including Adobe AFAIK

[jenne1978]

Hi everyone, thanks for all the comments. The reason why I am looking for a smaller raw file size is because my raw files are of a Canon 5D Mark II, who are around 20 megapixels, so around 20 megabyites. This is quit a lot. I am writing an image processing course and I would like to provide a cd with data files. Most of the time the 20 megapixel files just eat up valuable space, I just don't need them to be that big. I am aware of the options I have to make them smaller (DNG, ZIP, other camera) but I am looking for a method to make the existing raw files smaller. Compression only goes so far. I am also aware that this might very well not be possible because of the nature of the raw format. There are always workarounds, but that is not what I am looking for. I am not just looking for a practical solution for a practical problem. I can think of those by my self. But searching for the answer to the question whether you can resize a raw file or not came up with zero, so that is why I came asking here. I mean, it's an interesting question, right?

[Colin Southern]

Some "outside the square" thoughts ...

- Use a DVD instead of a CD (8x the capacity)

- Use something like Google Drive / Dropbox so that course participants can just download the files

DNG with lossy compression is the only way to drop the size of your existing files and still keep them RAW that I know of.

[dan marchant]

Given that you can't resize a RAW file why not just shoot a few images in mraw or sraw?

[davidedric]

But searching for the answer to the question whether you can resize a raw file or not came up with zero, so that is why I came asking here. I mean, it's an interesting question, right?

An interesting question, and I understand you are not looking for workarounds. I suspect that you have got most of the answers that you will from here. If you haven't already you could try posting the same question on Luminous Landscape - maybe Jeff Schewe or one of the other 800 pound gorillas of the pp world will reply. They tend not to be quite so gentlemanly as CiC members, mind