equial or less quality ????

when you shoot in raw, will you loose any quality processing your photos after you convert them to jpeg ? or should they be processed befor conversion ? im new at all this and eager to learn, you all have been my greatest resource, thanks for responce.

-bentwig-

A raw format file doesn't have any "quality" - it is simply raw data read off of the camera's sensor. It has to be processed to view it or do anything with it. Processing the raw file doesn't change the original raw data, so you can always go back and re-process it.

After the raw data has been processed/converted, you can save it as a TIFF file if you want the very best image quality, but if you have it as a low compression (highest quality setting) JPEG the difference will be very small.
--
Chris R

'RAW' is just what you think it is, raw information on the light every sensory point on your chip has captured. With this data, you tell a computer (the one inside the camera or your PC) to make a bitmapped picture out of that. That would be a picture where every pixel has a combined value of some of these sensor points, giving it a unique color.

While 'developing' RAW data you tell the computer HOW to do this 'demosaicing'. Using the original raw data for that gives you the advantage of the headroom of data it has.

After you're done with the settings, you can save the bitmap-picture in different ways, JPG being one of those. It's a compressed format, so you will loose some image data (pixel information, not RAW-data) while saving. You will get a far smaller filesize though than when using an uncompressed filetype.

TIF is a lossless format, which you can use with or without compression.

Also you can export the file directly to PS and save it as a PSD-file, also lossless.

Those names, JPG, TIFF and PSD, all are bitmapped images. Your RAW file will still exist after you have develloped it into one of these formats.

bentwig said:

when you shoot in raw, will you loose any quality processing your photos after you convert them to jpeg ? or should they be processed befor conversion

Click to expand...

If you convert the image to JPEG before processing it, you might as well shoot in JPEG and skip a step.

When working on the image, if I want to save intermediate steps, I'll save in the software's proprietary file type (PSD for Photoshop, CPT for Corel PhotoPaint). Of course you should be saving your work as you progress, in case you suffer a crash in the middle of it.

The RAW file contains the maximum amount of information. Conversion to JPEG is a one-way trip. That is, some information is discarded during the conversion, so that it is impossible to reconstruct the RAW file from the JPEG.

This is not related to the losses due to JPEG compression, which is a separate and additional cause of information being lost.

Some people convert from RAW to a lossless format such as TIFF before carrying out any additional processing. This is a better strategy to retain a more information, but the original point still stands, the RAW file cannot be reconstructed from the TIFF as it does not contain all of the original information.

As others have stated, a proprietary format such as PSD is a good idea, and in my opinion is better than TIFF or JPEG during the editing process.

Regards,
Peter

Mike_PEAT said:

bentwig said:

when you shoot in raw, will you loose any quality processing your photos after you convert them to jpeg ? or should they be processed befor conversion

Click to expand...

Click to expand...

To add one more point to my answer, only convert to JPEG if you intend to do stuff like upload it online, send it to a print service that only accepts JPEGs, or want to share it (via email).

If you are just working on the image to print it yourself, you DON'T need to convert to JPEG...you can print right in your photo editing program from the PSD (or whatever) file type. If you save to JPEG first you're throwing away a lot of information.

ok Im getting A better idea of what raw is, I think ? If I choose to retain the quality that I can get from A raw file it must remain A raw file, just do my PP then save - leaving it raw, and if I choose to make prints made up at some place like costco they just develop from the raw file ?

bentwig said:

ok Im getting A better idea of what raw is, I think ? If I choose to retain the quality that I can get from A raw file it must remain A raw file, just do my PP then save - leaving it raw, and if I choose to make prints made up at some place like costco they just develop from the raw file ?

Click to expand...

Unless I don't understand your English, that's not the message.

• The RAW file cannot be displayed on the screen.

• When the program reads the RAW file, it has to convert the RAW file in memory into a picture on the screen.

• The picture on the screen is not RAW - it is a picture on the screen. It has not be saved back.

• You now may want to adjust crop, adjust brightness, colour, contrast, sharpness, whatever. When you have finished doing that, you need to save otherwise when you quit the program all the adjustments are gone.

• So you have to save. You can save .TIFF, .PSD, .JPEG, .PNG, .BMP.

• If you haven't finished work but want to shut down the computer and come back after lunch to work on the file, then to reduce the loss of quality, you save as for example 16 bit lossless TIFF. If you are a Photoshop user, you might want to save it as a .PSD - but I don't use Photoshop so I don't know.

• If you have finished work and just want to take the photo to Costco, many of these companies accept only 8 bit lossy JPEG because that is the common file every mom and dad use to sent to them. So you save it as 8 bit JPEG.

• Except for some hackers, you can't save back or write over the original RAW file.

• Some programs can save a settings file to pair with each RAW file (I haven't followed this). So you can save this and go for lunch. But before you send to Costco, you still need to save a .JPEG.

--



Ananda
http://anandasim.blogspot.com

'There are a whole range of greys and colours - from
the photographer who shoots everything in iA / green
AUTO to the one who shoots Manual Everything. There
is no right or wrong - there are just instances of
individuality and individual choice.'

ok, THATS JUST THE AWNSER I WAS LOOKING FOR ! thanks A lot. it took me A while but tha explains why - when I made changes to A raw file and went back later and clicked on the raw file the changes wher gone, I pressed save changes but did'nt specify to what format, and therefor loosing my changes. correct or not ?

bentwig said:

ok, THATS JUST THE AWNSER I WAS LOOKING FOR ! thanks A lot. it took me A while but tha explains why - when I made changes to A raw file and went back later and clicked on the raw file the changes wher gone, I pressed save changes but did'nt specify to what format, and therefor loosing my changes. correct or not ?

Click to expand...

Depends on what program. In theory, correct, you can't save back to the RAW file.

In Picasa, changes are save to one common settings file in the folder. Then you have to generate JPEG after you have done looked over all your files. In Lightroom and Raw Therapee, they save info to another file. You workflow is not complete until you export or save as JPEG.

--



Ananda
http://anandasim.blogspot.com

'There are a whole range of greys and colours - from
the photographer who shoots everything in iA / green
AUTO to the one who shoots Manual Everything. There
is no right or wrong - there are just instances of
individuality and individual choice.'

ok , thank's now I can move forword. I still have my work cut out fore me, but that just became one less obstacle.