Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
11-23-2010, 03:51 PM   #1
Veteran Member




Join Date: Jan 2007
Location: New Mexico
Photos: Albums
Posts: 1,125
What's with the red channel at high ISOs?

I know that the Imaging Resource K-5 jpegs show smearing of reds in the Still Life shots, but so do the DNGs at ISO 12,800 and above. Is this an artifact of ACR, or is it a limitation of the sensor at that ISO?

Rob

11-23-2010, 04:25 PM   #2
Pentaxian
JohnBee's Avatar

Join Date: Sep 2008
Location: front of computer
Posts: 4,620
Have you downloaded the looked at the DNG's locally, or are you reffering to the accompanying DNG images hosted by IR? Because its quite common for people to think the web images are the DNG's, but in reality, they are actually in camera JPG's.

The best way to assess DNG/RAW files from IR, is to download them and evaluated them locally.
Having said that, I took a look at them several weeks ago and found the ISO12800 K-5 DNG files to look better(more detailed) in the red channel than the D7K at this sensitivity.

Hope this helps.
11-23-2010, 04:40 PM   #3
Veteran Member




Join Date: Jan 2007
Location: New Mexico
Photos: Albums
Posts: 1,125
Original Poster
QuoteOriginally posted by JohnBee Quote
Have you downloaded the looked at the DNG's locally, or are you reffering to the accompanying DNG images hosted by IR? Because its quite common for people to think the web images are the DNG's, but in reality, they are actually in camera JPG's.

The best way to assess DNG/RAW files from IR, is to download them and evaluated them locally.
Having said that, I took a look at them several weeks ago and found the ISO12800 K-5 DNG files to look better(more detailed) in the red channel than the D7K at this sensitivity.

Hope this helps.
John,

I downloaded the K-5 DNGs and opened them in ACR. I was unable to do the same for the D7000 NEFs, because ACR does not yet support them. Strange that IR did it that way. Do they have a newer version of ACR than the rest of us?

Rob
11-23-2010, 04:43 PM   #4
Pentaxian
JohnBee's Avatar

Join Date: Sep 2008
Location: front of computer
Posts: 4,620
QuoteOriginally posted by robgo2 Quote
John,

I downloaded the K-5 DNGs and opened them in ACR. I was unable to do the same for the D7000 NEFs, because ACR does not yet support them. Strange that IR did it that way. Do they have a newer version of ACR than the rest of us?

Rob
Yes, they do in fact.
Adobe released an beta ACR upgrade(found here).


Last edited by JohnBee; 11-23-2010 at 06:49 PM.
11-23-2010, 06:00 PM   #5
Veteran Member




Join Date: Jan 2007
Location: New Mexico
Photos: Albums
Posts: 1,125
Original Poster
QuoteOriginally posted by JohnBee Quote
Yes, they do in fact.
Adobe released an beta ACR upgrade(found here).
It's an update of Lightroom 3, which I do not own or intend to purchase. I use ACR in CS5, but only for the purpose of opening DNGs not yet covered by Capture One. Which means that I will have to wait for the release of the actual ACR update.

In any case, John, are you saying that the D7000's raw files at 12,800 are not better than the K-5's?

Rob
11-23-2010, 06:07 PM   #6
Site Supporter
dave kitson's Avatar

Join Date: Sep 2006
Location: Lichfield, UK
Photos: Gallery | Albums
Posts: 473
QuoteOriginally posted by robgo2 Quote
It's an update of Lightroom 3, which I do not own or intend to purchase. I use ACR in CS5, but only for the purpose of opening DNGs not yet covered by Capture One. Which means that I will have to wait for the release of the actual ACR update.
Rob

Try here for the ACR 6.3 pre-release:
Adobe Labs - Adobe Photoshop Camera Raw 6.3

dave
11-23-2010, 06:23 PM   #7
Veteran Member




Join Date: Dec 2007
Posts: 923
QuoteOriginally posted by robgo2 Quote
I know that the Imaging Resource K-5 jpegs show smearing of reds in the Still Life shots, but so do the DNGs at ISO 12,800 and above. Is this an artifact of ACR, or is it a limitation of the sensor at that ISO?

Rob
Right now I'm using PEFs with the Pentax DC Utility 4 which came in the K-5 Box.

There is the expected progressive reduction in detail at high ISOs 12,800 and above (still very impressive) but I have not noticed unusual smearing of Red colour from the PEF output.
So I don't think its a sensor problem
11-23-2010, 06:51 PM   #8
Pentaxian
JohnBee's Avatar

Join Date: Sep 2008
Location: front of computer
Posts: 4,620
QuoteOriginally posted by robgo2 Quote
It's an update of Lightroom 3, which I do not own or intend to purchase. I use ACR in CS5, but only for the purpose of opening DNGs not yet covered by Capture One. Which means that I will have to wait for the release of the actual ACR update.
Gak!
Sorry about that.
I applied the wrong link for the update.
As dave kitson mentioned, the ACR update is available as well.
I also update my own original link to avoid further confusion.

QuoteQuote:
In any case, John, are you saying that the D7000's raw files at 12,800 are not better than the K-5's?
Correct.
However, I haven't run them through or anything, I just based my assumption on a quick visual.
But as far as I can see, the K-5 looks better than the D7K in the red channel at ISO12800, no ifs, and's or, butts

11-23-2010, 07:00 PM   #9
Pentaxian
JohnBee's Avatar

Join Date: Sep 2008
Location: front of computer
Posts: 4,620
To help illustrate, here are two ACR 1:1 samples to look over(no PP or NR):

Granted, they are both very poor in terms of original detail.
However, I think the K-5 comes-out on top with respect to making the best out of poor IQ when all is said and done.

D7K, ISO12800 NEF/RAW:


K-5, ISO12800 DNG/RAW:
11-24-2010, 03:00 AM   #10
Pentaxian




Join Date: Mar 2009
Location: Perth Australia
Photos: Albums
Posts: 1,511
Its pretty lame they use out of camera jpg's by default. I did think they were processed raws too.
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!
camera, dslr, iso, k-5, k-5 ii, k-5 iis, k5, pentax k-5
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pentax IRC channel Nimrad Photographic Technique 5 01-26-2015 09:13 AM
changing flash channel SebastianP Flashes, Lighting, and Studio 2 11-09-2010 03:36 AM
Pentax W90 - noise at higher ISOs gubak Pentax Compact Cameras 2 10-22-2010 12:03 PM
Tamron's YouTube Channel Clicker Photographic Technique 1 01-11-2010 04:21 PM
8 bits per channel -vs- 16 bits per channel Ed in GA Digital Processing, Software, and Printing 5 03-25-2008 09:02 AM



All times are GMT -7. The time now is 08:31 AM. | 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