Save as RAW

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Fergie
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I've read of you guys recommending that photos for archiving are best saved as RAW files, and so I thought I would try that.

They save ok but when I try to open them in PS 7 they come up as stretched out, greyscale type, grainy images.

Would anyone care to tell me what I am doing wrong and what is the advantage of saving as RAW files as compared to BMP for instance ?

Cheers

               
                  Fergie
There's only one eF in Ferguson

I now seem to spend a lot of time arguing with inanimate objects

fuddam
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it's not so much as saving them as raw, but capturing them originally in raw, in the camera.
raw captures the full digital image off the sensor, and whatever software you use to edit them, edits a small file attached to the image, describing changes you have made, eg exposure, white balance, sharpness etc
the benefit is that the original image data is unaffected by the 'edits' you make, so you can undo any changes at any later stage. You are simply altering the small file. Gives you greatest latitude with the image for future use.

easy example (but not limited to RAW) is what happens when you use Picasa to edit an image. The actual changes are stored in the picasa .ini file found in the folder with the images.

my 2c

foxvideo
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If I remember, PS7 needed the Camera Raw additional plugin????? (From the Adobe site)

The advantage to RAW is that it's similar to using a negative, there's no compression applied (like JPEG), it's just all the raw data needed to make up the picture. RAW is very adjustable to WB correction, exposure correction etc.

There are many arguments for/against using RAW - it's more down to personal workflow/choice.

Dave Farrants Fox Video Editing

Alan Roberts
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I think that RAW means much more than all that. a RAW file is a file whose content and structure is not defined by any of the normal standards, it can be absolutely anything you want it to be. So, the camera manufacturers aren't bound by standards, and can each launch their own version without letting on what's inside (I do exactly this in my own software). And this means that you are stuck with software from the same supplier to decode the files, there's no agreed format.

If the way of using it is as has been outlined, the original data from the sensor held unmodified, but with meta-data describing what's to do with it, then you get big files but you can always backtrack to the original. Most of the standardised image formats have 8-bit data, 256 levels in R G or B, but with RAW you can have anything you like, provided you can accept the bigger file.

Incidentally, just because the file is nominally RAW doesn't mean it isn't compressed; most RAW files are compressed in some way, but maybe using "transparent" compression that's supposed not to throw anything away, like ZIP of LZW-compressed TIF.

So, if you want to work with RAW files, you're best to use the camera's RAW format and to stick with the software from the camera's supplier, or you'll get all sorts of problems.

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
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Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

foxvideo
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Alan Roberts wrote:
So, if you want to work with RAW files, you're best to use the camera's RAW format and to stick with the software from the camera's supplier, or you'll get all sorts of problems.

Never thought I'd disagree with Alan......;)

There are many non camera manufactures versions of good RAW conversion programs.

RawTherapee (free) - Very good
Stepok's Raw Importer (free) - Not tried it
RAW Shooter Essentials (free) and still available if you look for it - Excellent program but sold out to Adobe :mad:
LightZone (not free but exceptional value for money) Excellent prog with trial download

Dave Farrants Fox Video Editing

Alan Roberts
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Fair enough, but my point was that there's no international agreement on RAW format, unlike, say JPEG or TIF or BMP.

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
Camera settings documents are held by Daniel Browning and at the EBU
My book, 'Circles of Confusion' is available here.
Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

foxvideo
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Now I'll agree to that (I think!), I'll accept your superior technical knowledge there ;)

There are hundreds of forum discussions (some very heated!) on the pros/cons of RAW vs JPEG and in practical terms it comes down to what you shoot, how you shoot and what you want at the end. It's impossible to shoot continuous RAW on long bursts with the lower spec'd DSLR's - the buffer just can't cope although this is improving with each model upgrade. If you're just shooting the kids in the garden and want a couple of pictures for a web gallery, RAW is almost a waste of time but if you're a pro trying to shoot a wedding when the light is changing faster than you can adjust your exposure comp button for a white dress/black suit, a RAW can be 'saved' when the exposure or white balance is way off - I rescued some 1.5f stop under shots recently and was thankful I was using RAW not JPEG!

Dave Farrants Fox Video Editing

Fergie
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My small Finepix A600 isn't capable of captuing as RAW, but I thought I could save as RAW as it's one of the options in PS.
If RAW is not an option, would saving as BMP be recomended. Or even Photoshop's own PSD. But if I saved as PSD then I would only be able to open files in Photoshop, wouldn't I ??

I am asking this because I have noticed a drop in picture quality to JPEG files that have been re-edited and /or moved about between files.

Cheers.

               
                  Fergie
There's only one eF in Ferguson

I now seem to spend a lot of time arguing with inanimate objects

Alan Roberts
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If, at any point in the chain of processing that file has had, you've saved in anything but the original RAW format, then there'll be no point in saving as RAW. Once it's in 8-bit form (JPEG, TIF, BMP etc) then you gain nothing by going to RAW. BMP is totally uncompressed (usually) and therefore 100% safe (but big), but LZW-compressed TIF gives identical performance although compressed (it's exactly the same algorithm as ZIP compression).

I capture almost everything in the camera as JPG, and store pictures that way, unmodified. If I've done anything to a picture, I'll save it as a separate copy. That way I can always get back to the original. I normally use TIF for the copies.

Hope that helps.

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
Camera settings documents are held by Daniel Browning and at the EBU
My book, 'Circles of Confusion' is available here.
Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

Fergie
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It does Alan, Thanks :)

And thanks too of course to fuddam and Dave. .:p

               
                  Fergie
There's only one eF in Ferguson

I now seem to spend a lot of time arguing with inanimate objects

Fergie
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Alan Roberts wrote:
I normally use TIF for the copies.

Just to be clear Alan, is that TIF with no compression or with LZW. ??

Cheers.

               
                  Fergie
There's only one eF in Ferguson

I now seem to spend a lot of time arguing with inanimate objects

Alan Roberts
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It doesn't make any difference to the pictures, LZW compression is lossless. Uncompressed TIF is the same as BMP. The file headrers are different, of course, but the image content isn't. I always use RGB LZW in TIF.

Beware that TIF has a 16-bit mode apparently, but I don't know of any software that uses it fully.

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
Camera settings documents are held by Daniel Browning and at the EBU
My book, 'Circles of Confusion' is available here.
Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

Fergie
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Thanks again Alan

               
                  Fergie
There's only one eF in Ferguson

I now seem to spend a lot of time arguing with inanimate objects

Chris.
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Adobe developed a 'standard' for camera RAW files, DNG (Digital NeGative). It's worth converting your proprietary RAW files to DNG if you're worried about only being able to access them with a restricted software set in future. Adobe's DNG converter is free.

The way memory card prices have fallen I shoot a lot in RAW mode, (or RAW +JPG)

As RAW processing software matures you can revisit old RAW files and try new processing methods on them.

I treat my RAWs like negatives, generating a 16 Bit TIFF when required (eg for printing) or outputting a JPEG (for web, email etc).

Photoshop CS3 will let you work on the files in 16 bit and includes 16 bit versions of nearly all of the filters and adjustments. In CS2 a lot of the filters were 8 bit only.

Alan Roberts
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Sounds good. The process of storing unmodified originals is an essential part of it.

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
Camera settings documents are held by Daniel Browning and at the EBU
My book, 'Circles of Confusion' is available here.
Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

David Pearson
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Joined: Nov 20 2000

One more reference - see http://luminous-landscape.com/tutorials/jpg-follies.shtml. For my SLR work I nearly always shoot RAW+JPEG - and then put the RAW files to one side just in case I want one for that priceless pic or one that needs to be salvaged. Equally, if I want/need to process something I'll usually work on the RAW version.

Yeah, even with a top-end SLR RAW+JPG can fill the buffer PDQ. I was at Biggin Hill yesterday (Alan, I suspect they reach even you?!) and a blast at full speed of a speeding Eurofighter fills the buffer all too quickly (but my Canon 40D does recover VERY quickly).

Alan Roberts
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Yep, saw some interesting over-flights :)

You've put your finger on the benefits and pains of using RAW. The RAW original lets you backtrack for processing, but uses lots of space, and takes a lot longer to store in the camera. But it makes no sense to store as RAW when the original isn't RAW, and it makes little more sense to store a processed file as RAW either.

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
Camera settings documents are held by Daniel Browning and at the EBU
My book, 'Circles of Confusion' is available here.
Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

fuddam
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Joined: Nov 19 2005

I find the nikon RAWs to be almost the same size as a jpeg shot at highest res. No real difference. don't know how the canon RAWs compare

Chris.
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Joined: Nov 5 2000

Some Nikon DSLRs can compress their (NEF) RAW files. There's a bit of a debate about whether information is lost when they do this. For example

I wonder why there's an option not to compress the RAW files? Is that because they do throw away some information, or is it a speed issue? On the speed thing, you'd have to compare how quickly a larger uncompressed file can be written to a card versus the speed of compressing then writing a smaller file.

When you shoot only RAW with a Canon a small JPEG is still saved (it's used for displaying the image on the camera's LCD and in some software) It's embedded in the RAW file and can be extracted by the likes of BreezeBrowser

Chris.
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Joined: Nov 5 2000

I should echo what people have said to the original poster.

Shooting as JPEG then converting to RAW seems totally pointless.

If you don't edit your JPEGs then leave them as they are until you need to edit them. If you work a lot on a file and return to it to tweak things you should definitely not keep resaving it as a JPEG, save in a lossless format like TIFF.

I've overheard people in Jessops spouting complete garbage about JPEG. Things like they degrade every time you open them. Complete rubbish. There's some good webpages about JPEG myths

Fergie
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Chris Longley wrote:
If you work a lot on a file and return to it to tweak things you should definitely not keep resaving it as a JPEG, save in a lossless format like TIFF.

That is exactly the mistake I have been making.

Cheers.

               
                  Fergie
There's only one eF in Ferguson

I now seem to spend a lot of time arguing with inanimate objects