Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-05-2008, 07:09 AM   #16
Veteran Member




Join Date: Nov 2006
Location: Hong Kong
Posts: 1,934
Number of Bits

QuoteOriginally posted by jeffkrol Quote
More bits the better. There can be little arguement between 256 colors vs 4096.
Who in their right mind even uses a monitor at 8 bit color?
How many bits are our monitors able to display, then? What monitor do you use? LCD or CRT? I'm really very curious to know..

04-05-2008, 07:29 AM   #17
Veteran Member
jeffkrol's Avatar

Join Date: Sep 2006
Location: Wisconsin USA
Photos: Gallery
Posts: 8,435
Mitusbishi 2070sb CRT.
Funny, it won't even allow me to use 8bit

As iI stated earlier it is impossible to gain by throwing information away.
You can always argue you lose little.. but you LOSE nevertheless.....

Last edited by jeffkrol; 04-05-2008 at 07:36 AM.
04-05-2008, 07:46 AM   #18
Veteran Member




Join Date: Nov 2006
Location: Hong Kong
Posts: 1,934
QuoteOriginally posted by jeffkrol Quote
Mitusbishi 2070sb CRT.
Funny, it won't even allow me to use 8bit

As iI stated earlier it is impossible to gain by throwing information away.
You can always argue you lose little.. but you LOSE nevertheless.....
So, how many bits should you choose there in order to *fully* display a jpeg image??
04-05-2008, 08:21 AM   #19
Veteran Member
Ivan Glisin's Avatar

Join Date: Nov 2006
Location: Belgrade
Posts: 656
QuoteOriginally posted by RiceHigh Quote
Also, just don't think RAW is completely "raw", which is non-existent on this planet - they just have more bits afterall.
That "just" is in most cameras 16 times more information per channel and the main reason to use RAW over JPEG: while JPEG is just fine for minor adjustments, RAW is absolute necessity for more aggressive editing and especially for proper B&W conversion in order to retain full tonal values once converted to a final output format, which is usually 8-bit.

04-05-2008, 08:50 AM   #20
Senior Member




Join Date: Feb 2008
Location: U.S. /Miami - Florida.
Posts: 208
Rent again and shoot portraits against the K20D and i wanna see your review Just curiousity.


vic jr
04-05-2008, 09:31 AM   #21
Veteran Member
nostatic's Avatar

Join Date: Feb 2008
Location: socal
Photos: Gallery
Posts: 1,576
QuoteOriginally posted by RiceHigh Quote
Yes, I shoot 95% of the time in jpeg mode with my 5D whilst with my K100D I shoot nearly 100% of the time in RAW mode. So, according to your proposition, my 5D must be a P&S and my K100D must be a pro DSLR! ;-D
No, that isn't what I said. But some people rarely will engage a point directly.

It does explain a lot about your "reviews" actually...

Last edited by nostatic; 04-05-2008 at 10:14 AM.
04-05-2008, 05:46 PM   #22
Veteran Member
roentarre's Avatar

Join Date: Oct 2006
Location: Melbourne, Australia
Posts: 11,794
Seriously, I would only use 5D under low lighting predominantly on protraits or people's shots. Otherwise I do not see much advantage of this camera over k20d.

I know the next model Canon 4D is on the way, 2 shooting modes: 33 MP and 15MP. Given the experience with 5D, I am very keen to look into this forth coming model.

For landscape, wild life and macro, I am sticking with pentax. Canon often gives me the white out colour, plasticky feel to the images.

FF advantage to me (on 5D and 1d experience) is really the greater bokeh and brighter viewfinder...
04-09-2008, 10:12 AM   #23
New Member




Join Date: Feb 2008
Location: Denver, CO
Posts: 10
QuoteOriginally posted by jeffkrol Quote
More bits the better. There can be little arguement between 256 colors vs 4096.
Who in their right mind even uses a monitor at 8 bit color? When it comes to photography for more than just snapshots I really see no need in ever crippling your pallete shooting jpg. Not to even mention the compression aspect...
Yes, jpg is "fine" but why?????????
Maybe just me but I never ever will understand the jpg vs raw arguement. Converts your image to the equivalent of a polaroid (instant film) as compared to a true negative/slide. If your camera shoots great jpgs, even more reason to shoot in RAW. It is possible that your images could be ever so slightly better..... and converting to 16bit Tiffs w/ a jpg "preview" or "for the web" gives you everything. Not just a shadow of the data...
Clarkvision: Digital Camera Raw versus Jpeg Conversion Losses
To be honest the above link has enough info to argue in both directions. Bottom line though is why? If the image is just fine, convert it to jpg LATER, when you have time to critique it more and then if you so choose, delete the RAW (I'd wager 70% would still save it, mostly, just because.. ). Storage is dirt cheap and multiple cards (rather than have 100's of files on one) is a bit more insurance against complete loss....
Intresting arguments.

First off to the display. I would assume that you use a LCD display. If you connected the LCD via analog VGA cable, then the internal ADC of the LCD and it's AA filters will dictate the color accurancy. If you connect via DVI you will have usually 6 bits per color component, while more expensive LCDs will actually offer 8 bits. Some are in between as they really have only 6 bits per primary but use on the fly dithering so that you'd see more colors. Most LCDs for Laptops do offer only 6 bits per primary. Now this is where things get hairy. LCDs do have a different gamma curve that the expected default in sRGB. So if the LCD does that correction behind your back you'd end up with a lot of posterization effects. So the only real good solution here is the leave the gamma of the LCD alone, and do proper color calibration on the host side (i.e. Lightroom, CS3 ...) But wait, if you map 8 bits per channel incoming to 8 bits per output channel throu gamma correct, you'd loose quite a few of the theoretical possible 256 shades, which results in the loss of 1 LSB or 2 LSBs (should I say that you are really screwed if you have only a Laptop LCD). Highend systems in the days of analog CRTCs battled this by actually having 10 bit dacs. Just as a sidenote, Windows XP/Vista do not allow GDI surfaces with 10/10/10/2, only 8/8/8/8 ...

Now to the RAW vs. JPEG argument. It is my understanding (and I might be wrong as well there), JPEG usually applies gamma correction to sRGB/Adobo-RGB, while RAW is the real sensor data, uncorrected. Thus the 12 bits in RAW will be probably equivalent to 10 bits in reality after you applied the gamma correction, and got rid of the random noise in the LSBs. So yes, RAW has a slight advantage here. On the other hand the in-camera conversion from sensor data to JPEG can take advantage of more Camera/HW knownledge than a generic 3rd party utility can.

However there is one point most people seem to miss about JPEG. In essence it's a YUV422 encoding, while means it's not really RGB, but a different color space (Y == luminance, UV == chrominace, sometimes also called YCrCb ...). It also means that for every 4 samples of luminance there are only 2 samples of U and 2 samples of V. Thus even if JPEG claims 8 bits per components, it's not quite true, as the U & V components need to be interpolated per Y component. And this does not even take IDCT and quantisation into consideration. If you want to be really picks you also have to understand that the Y component uses only 240 levels out of 256 possible ones per specification

So yes, JPEG does have substantially less precision per component than RAW, more so than the usual 14bit vs. 8bit rule of thumb implies.

But what the realy killer is, is that most image processing applications default to a 8 bit path for JPEG, and a 16 bit path for RAW. So all things being equal, you end up with more rounding errors in postprocessing for JPEG than for RAW. With the different sampling I would also assume what you have less chrominance sharpness to play with for JPEG.

At the end of the day it's funny though. All consumer setups per default go for sRGB (Laptop, Desktop, LCDs, printers), so that if you use JPEG with sRGB, there is less chance that you screw up your imaging pipeline from the beginning to the end, and produce acceptable results without worry. If on the other hand you use RAW and do not follow throu with proper color calibration and other associated settings, chances are you screw things up.

BTW, I use RAW because I can. I like to tinker, and I do screw up things every now and then.

Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
5d, camera, conditions, dslr, ff, iso, k10, k20, light, pentax, photography, shots
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Question to K-r users Mystic Pentax K-r 7 10-26-2010 02:42 PM
Question for Nikon users axl Non-Pentax Cameras: Canon, Nikon, etc. 8 09-11-2009 02:43 PM
Ricehigh: No More Hope With Pentax Asahiflex General Talk 143 07-11-2009 12:14 PM
K-7 users question Mystic Pentax DSLR Discussion 3 06-02-2009 09:37 AM
Question for european users! mikerigel General Talk 4 03-19-2008 05:44 AM



All times are GMT -7. The time now is 08:11 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top