Raw Images and an apology!!!

Dennis G · #1 08-02-2010, 04:51 PM

The First Raw Picture marked RAW .CR2

I apologise to all who gave their time re RAW exposure. My stupidity for not pressing Set after choosing the camera setting for RAW!!! I saw my first RAW .CR2 pics after doing so. Now I’ve to work on, How to process RAW. The attached pic of my observatory was taken as RAW and transferred to Photoshop where it became a TIF file. Is this the way to go? Microsoft program free on the net :Raw Image Thumbnailer and Viewer . Is this worth the down load? I tried yesterday but failed to get it to open. Your advice and suggestions would be welcomed. Thanks for your patience and assistance.
Couldn't load Tif File

gbeal · #2 08-02-2010, 05:21 PM

Hi Dennis,
can't help you with the RAW issue as it will be different to the Sony I have.
The reason you can't upload the TIFF is likely the size. Any TIFF I have had anything to do with has been humoungous, and bigger than what is allowed in posting. Try a JPEG instead.
Gary

leinad (Dan) · #3 08-02-2010, 05:37 PM

Dennis,

Canon's Digital Photo Professional comes on the Canon Software disk and can help you preview, convert RAW to JPEG; resize, etc. before importing to Photoshop.

See here for a few tutorials on DPP.
http://www.usa.canon.com/content/dpp2/index.html

To save an attachment or upload an attachment I should say; the filesize needs to be less then 200kb for a JPG.

You can reduce the file size by either cropping/resizing the image, or reducing the Quality when you save to JPEG from Photoshop.

telecasterguru (Frank) · #4 08-02-2010, 05:46 PM

Dennis,

What version of Photoshop are you using? If you have PS3 or later I believe you can use Bridge to open and process the CR2 image.

If not, in DPP you must convert and save before PS will open it. This can be to tiff or jpeg.

When it is open in PS you need to resize the image, usually to about 800 pixels at its longest side, and save for web before you can post it. It needs to be smaller than 200k before it can be uploaded.

I understand there are tutorials on how to do this both on this site and on the Ausphotography website. It is quite simple and takes very little time.

If you already have DPP and PS then I don not think you will need a thumbnail viewer.

If you get stuck just holler.

Frank

Dennis G · #5 09-02-2010, 02:24 PM

Ice in space is a God send for we beginners and the friendly replies are great.It proves there are nice folk in the world!
Now that I have the RAW exposure sorted out I'll work on processing them. I think Deep Sky Stacker accepts CR2 images and when this heat trough that is over us moves east, we should get a clear night with no moon to make a few tests. One question. Why do we use RAW for Astro images?
Dennis

telecasterguru (Frank) · #6 09-02-2010, 02:39 PM

Dennis,

My understanding is that RAW images are used because of the amount of data in them. If you use JPEG a lot of the data is lost when the file is compressed and stored. No data is lost in RAW and therefore there is more data to play with when processing.

Frank

leinad (Dan) · #7 09-02-2010, 02:42 PM

Here's a nice, easy to understand explanation of the 'RAW file format'

http://www.cambridgeincolour.com/tut...ile-format.htm

cfranks (Charles) · #8 11-02-2010, 02:52 PM

As Frank said, RAW files contain all the photons captured. Compress to JPEG and a lot of data is lost and cannot be recovered. Do all your post processing in RAW/TIFF and then convert to JPEG if required.

Charles