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Old 13-09-2007, 05:17 PM
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RAW or JPEG

are the DSLR users shooting mainly in raw or jpeg mode.
if shooting raw is in camera noise reduction turned of and then dark frames become more critical.
also if capturing in raw mode are the processing procedures the same, l am assuming more processing would be needed. thanks.
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Old 13-09-2007, 06:26 PM
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I have found processing in JPEG is more difficult as the images are already compressed and White balance set, sometimes on the wrong setting for Astro work. I would also thing that compression artifacts would increase the more images that are stacked, giving a poorer final image. I always shoot RAW, it gives you the flexibility to manipulate your images to the way you think they should look. ICNR can be on or off in RAW mode, I am still yet to see which is better, shooting your own Darks or let the camera do it. Personally I would let myself do the Darks as it gives you more of a chance to get the object you want without waiting for darks to be applied on every image. Personal preference of course. I have seen Bert using ICNR most of the time, absolutely nothing wrong with that at all.
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Old 13-09-2007, 07:09 PM
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iceman (Mike)
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I always use RAW. I think there was a poll about a month or two with a similar question and there were many thoughts in that.
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Old 13-09-2007, 07:15 PM
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NEVER process a jpg. Each time you save, it compresses and you lose detail. If you do take a jpg, convert it to tif and then process. Generally, raw files are bigger and have more detail than any other option.
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Last edited by Geoff45; 13-09-2007 at 07:53 PM.
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Old 13-09-2007, 07:44 PM
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g__day (Matthew)
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I use RAW and at present let the camera dark frame subtract (doubling the duration of every shot). I use Photoshop CS2 to manipulate shots so RAW gives more options for control to me.
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Old 13-09-2007, 10:45 PM
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Jpeg is convenient Mick but RAW is the way to go. Especially once your proficiency builds..which it is.
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Old 14-09-2007, 09:52 AM
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I only use RAW, even for terrestrial shots.
You can still enable in-cam noise reduction when shooting RAW.
For astro images I calibrate my RAWs in IP 2.7 and finish off any adjusting in PS.
Processing RAW gives you so much more latitude when adjusting levels, WB etc.
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Old 14-09-2007, 10:47 AM
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Side question but on-topic I think.

If you use RAWS with in camera noise reduction(ICNR), is there much point in shooting Darks with the noise reduction applied by the camera too?

Or, could you shoot your light RAWs with ICNR then do Darks without ICNR for calibration in ImagesPlus for example?
Cheers
Doug
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Old 14-09-2007, 01:26 PM
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ving (David)
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hi mick

i use raw for terrestrial and jpg for astro. noise reduction on my camera is better in jpg than raw. i really dont do many astro shots tho
(i have taken about 1100 pics on my new dslr and 5 of them are widefield astro)

Last edited by ving; 14-09-2007 at 01:45 PM.
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Old 14-09-2007, 02:15 PM
SkySearcher (Daniel)
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I have only used my SLR for terrestrial shots thus far but definitely go RAW for any image I might want to play with. It is always much easier to play with white balance and such later on the computer rather than before taking a shot. It does take up a lot more room on your card though.
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Old 14-09-2007, 02:25 PM
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I always shoot Raw, with ICNR and never shoot any Darks at all, the Canon 5D looks after it very nicely, the only pain is if you are doing 10 shots at 5 mins each, for example, you have to wait an extra 50 mins for the process to end.

leon
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Old 14-09-2007, 02:27 PM
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Doug I always use the in camera noise reduction (ICNR) as it beats subtracting darks later hands down. The major problem is that the thermal noise is very dependant on the temperature of the sensor so nothing beats taking a dark straight after the light exposure . In fact the mere act of taking a long exposure will heat up your sensor to a higher temperature than with the camera just simply "on". You do not need to do any other correction apart from flats when using ICNR.
Canon does something very cunning at the actual pixel level so there is a minimum of thermal noise and amp glow(none!) with ICNR. Doing a dark correction later with software is correcting for noise at the colour image level that is interpolated from the Bayer data. This will introduce artefacts ie coloured spots these are absent from ICNR images.

I have done exhaustive tests with my 5DH and ICNR is the way to go. I have even done dark correction at the Bayer level with ImagesPlus and ICNR still wins! It doubles data collection time but the results a far better.

Use of RAW to 16 bit TIFF of course! Manipulating JPG's is a waste of time as it is non linear 8 bit kludge full of artefact.



Bert
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Old 14-09-2007, 02:36 PM
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i never shoot in RAW. I always use jpeg. after post-processing, i save the image in .tif format .

I might give Berts suggestion turning ICNR on a go. i do get colour spot artifacts in my images. Although i do agree with andrew giving more time shooting other objects too. I should start to learn spending an entire night dedicated to one object only rather than trying to find and shoot as many objects as possible.
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Old 14-09-2007, 03:06 PM
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Quote:
Originally Posted by EzyStyles View Post
i never shoot in RAW. I always use jpeg. after post-processing, i save the image in .tif format .

I might give Berts suggestion turning ICNR on a go. i do get colour spot artifacts in my images. Although i do agree with andrew giving more time shooting other objects too. I should start to learn spending an entire night dedicated to one object only rather than trying to find and shoot as many objects as possible.
Eric I'm amazed you don't shoot RAWs - but your pics are testament to the fact that you're doing something VERY right!!
I always shoot in RAW format then convert files to 16 bit TIFFs for stacking etc in ImagesPlus. What gets me is that a 12Mb RAW is converted into a 35Mb TIFF file
All the best
Doug
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Old 14-09-2007, 04:07 PM
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Yep, know what you mean Doug, dammed if i know why the file gets so big when you convert to Tif, but it all works, that's the main thing.

Now we know why we need large hard drives

Leon
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Old 14-09-2007, 04:15 PM
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cheers doug. don't forget after you processed the .tiff file in eg: photoshop CS2, the final image file becomes 65mb . i have like at least 3-4 different variations with my final image need multiple harddrives soon.
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Old 14-09-2007, 05:28 PM
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Quote:
Originally Posted by EzyStyles View Post
cheers doug. don't forget after you processed the .tiff file in eg: photoshop CS2, the final image file becomes 65mb . i have like at least 3-4 different variations with my final image need multiple harddrives soon.
At least storage media is always coming down in price
Doug
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