Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-03-2009, 03:50 PM   #1
Junior Member




Join Date: Jun 2007
Posts: 35
Question on ISO performance of K20d or K7

I'm considering upgrading from my k100d and had a question in regards to ISO performance...

If one selects a lower quality rating than the full 14.6 megapixels does it improve the effective noise at higher ISOs? In other words, if one was happy with ISO 1600 performance and dropped from 14 to 7 megapixel performance (which might be great for some situations), would I gain a stop or two in ISO performance?

It seems people want full frame for lower noise; is going to lower megapixels setting on the existing chip have a similar effect?

07-03-2009, 04:20 PM   #2
Ash
Community Manager
Loyal Site Supporter
Ash's Avatar

Join Date: Mar 2007
Location: Toowoomba, Queensland
Photos: Gallery | Albums
Posts: 22,695
Lowering pixel count doesn't give you an extra 'boost' in ISO performance - it just means that the existing (same) noise will be smaller and thus less noticeable.

FF vs APS-C is a different argument with regards to ISO performance - it's not just about pixel count - more to do with the combination of signal to noise ratio and number, size and density of photosites on the sensor, as well as the type of sensor system and camera noise reduction software...
07-03-2009, 05:34 PM   #3
Veteran Member
falconeye's Avatar

Join Date: Jan 2008
Location: Munich, Alps, Germany
Photos: Gallery
Posts: 6,863
- Reducing the pixel count reduces the pixel noise (as measured in dumb test reports), but not the image noise (how the image would look when printed).
Going to 1/4 of pixels (1/2 of size) is like going to SQRT(1/4)=1/2 of ISO. This is why posting noise samples in web resolution is so useless...

- Increasing the sensor surface captures more photons and decreases the image noise. But only if you compare at the same f-stop.
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, iso performance, megapixels, noise, performance, photography, question
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
K-r vs. K-x in high ISO performance bwDraco Pentax DSLR Discussion 15 12-11-2010 11:10 AM
K-5 vs K-7 First ISO performance testing (ISO-6400) starscream Pentax News and Rumors 95 09-25-2010 07:02 PM
Kx (jpg) ISO Performance UnknownVT Pentax DSLR Discussion 8 12-02-2009 12:29 AM
K20D High ISO Performance joelovotti Pentax DSLR Discussion 22 03-17-2009 06:47 PM
Better high ISO performance on "K20D"? switters Pentax News and Rumors 39 12-02-2007 01:06 PM



All times are GMT -7. The time now is 08:48 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