Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-09-2009, 09:21 AM   #1
Senior Member




Join Date: Jun 2008
Location: Upstate NY
Posts: 240
So how is K-7 sensor supposed to be improved then?

Let me preface this by saying that this is NOT A PENTAX BASHING THREAD. Thank you.

I just reviewed my first series of K-7 test shots. And while my general impression of this camera is that it is simply awesome, the sensor seems to be almost entirely identical to the K20D's, with no high-ISO improvement at all. A few threads here seem to bear this out. There appears even to be a bit of unappealing looking NR going on above 1600, even when I have it turned off on the menu.

PERSONALLY I DON'T MIND THIS. I was entirely satisfied with the K20D's IQ, and I'm satisfied here too. It's the other improvements that made me buy the K-7 and so far I think I am going to love it to bits. I am not a pixel-peeper, and actually like a little noise in an image, and these will print large and well, just like the K20D.

But if this is supposed to be an improved sensor, what's the improvement? Is it just in the processing speed?

07-09-2009, 09:26 AM   #2
and
Site Supporter
Site Supporter




Join Date: Mar 2007
Photos: Gallery
Posts: 2,476
its got 4 channel output instad of 2. supports better live view, video and has CAF.
IQ wise its 99% the same imo.
07-09-2009, 09:27 AM   #3
Veteran Member
nostatic's Avatar

Join Date: Feb 2008
Location: socal
Photos: Gallery
Posts: 1,576
QuoteOriginally posted by mabelsound Quote
But if this is supposed to be an improved sensor, what's the improvement? Is it just in the processing speed?
Probably the ability to deal with constant live view aka video.
07-09-2009, 09:42 AM   #4
Senior Member




Join Date: Jun 2008
Location: Upstate NY
Posts: 240
Original Poster
Well, live view is definitely much improved, and the video mode is great.

07-09-2009, 05:19 PM   #5
Pentaxian




Join Date: Jun 2009
Location: GMT +10
Photos: Albums
Posts: 10,895
Even just those changes outlined above do make it sound like some major changes have been made to the sensor hardware and supporting circuitry over that of the K20D. Live view, HD video, face detect, faster fps etc aren't trivial to implement, and also signal faster CPU performance and greater in-camera data handling bandwidth.

I wonder if the new, improved horsepower of the K7 sensor means there may still be some scope for further improvements to sensor performance (eg in ISO) via firmware tuning. I mean, there is a lot of computer horsepower under the bonnet of the K7 to take advantage of.

It sounds like Pentax were tweaking the hardware right up until the last minute prior to commercial availability of the K7.

Maybe now that the hardware is finally done and out in the hands of customers the next product evolution point can focus on firmware tuning.
07-10-2009, 03:36 AM   #6
Veteran Member
Dr_who's Avatar

Join Date: Jun 2009
Location: Edmonton, Alberta, Canada
Photos: Gallery | Albums
Posts: 691
also somewhere in there I would image buffer speed and how the sensor deals with the faster shutter can come into play as well.
07-10-2009, 04:00 AM   #7
Veteran Member




Join Date: Mar 2007
Location: Boston, PRofMA
Photos: Albums
Posts: 3,053
Have you guys compared shadow noise at all? The K20D has quite a bit of chroma noise in the shadows. The theory at the time was the 14-bit A/D converter (compared to the 22-bit A/D converter in the K10D) was the culprit, but I'm not sure that's the case since the D90 pics I've seen also seem to have quite a bit of shadow noise, so I'm thinking it's a CMOS "feature"...
07-10-2009, 04:08 AM   #8
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,401
if you read the releases and look at performance, I believe the main changes are the following.

it is much faster, the K20 could only do 10MP in continuous shooting, the K7 can run at 14MP in High quality JPEG, that is , in itself an improvement.

the main advertising was the sensor was optimized for video, and is much improved in live view as well. Both of these changes are probably to do with heat management, because live view and video have the sensor powered full time.

but I would have to agree, otherwise it is probably very miuch the same sensor.

I did not pick K7 over K20 for these features.

The K7 has much improved metering over the K20. I accepted there would be no substantial difference in image quality.,

07-10-2009, 04:42 AM   #9
Pentaxian




Join Date: Sep 2006
Location: Antwerp, Belgium
Photos: Gallery
Posts: 1,039
One thing I seem to read about repeatedly is that the K-7's sensor doesn't have vertical pattern noise anymore, contrary to the K20D when pushed too far. This may mean that the high ISO is more useable, meaning that even if noise levels are equal, at least the noise is more pleasing.

Perhaps K-7 owners present here can confirm or deny this?

Wim
07-10-2009, 05:45 AM   #10
Senior Member




Join Date: Jun 2008
Location: Upstate NY
Posts: 240
Original Poster
QuoteOriginally posted by Ishpuini Quote
One thing I seem to read about repeatedly is that the K-7's sensor doesn't have vertical pattern noise anymore, contrary to the K20D when pushed too far. This may mean that the high ISO is more useable, meaning that even if noise levels are equal, at least the noise is more pleasing.

Perhaps K-7 owners present here can confirm or deny this?

Wim
So far I haven't seen any pattern noise, but it took a while to get any out of the K20D, too.

By the way, metering DOES seem to be better on the K-7. I didn't mind the K20D's habitual highlight-preserving underexposures, but the K-7 seems to be less conservative and is willing to bring you right up to the edge. My exposures with FA and DA lenses are great so far, very little adjustment needed in post. The camera is overexposing the K 15mm, but that was the case with the K20D as well--it's a cinch to adjust the EV to suit.
07-10-2009, 07:11 AM   #11
Pentaxian




Join Date: Sep 2006
Location: Antwerp, Belgium
Photos: Gallery
Posts: 1,039
QuoteOriginally posted by mabelsound Quote
By the way, metering DOES seem to be better on the K-7. I didn't mind the K20D's habitual highlight-preserving underexposures, but the K-7 seems to be less conservative and is willing to bring you right up to the edge. My exposures with FA and DA lenses are great so far, very little adjustment needed in post. The camera is overexposing the K 15mm, but that was the case with the K20D as well--it's a cinch to adjust the EV to suit.
Indeed. If metering is improved, images will require less pushing in post-processing and noise will not be as apparent in the final images either. Though this is not a consequence of the sensor itself, it does result in better noise.

Wim
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, improvement, k-7, photography, sensor
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Any idea when the K-5 is supposed to ship? m8o Pentax News and Rumors 2 09-19-2010 12:48 AM
Landscape Sun Glare: I thought it was supposed to be a bad thing! Jamfke Post Your Photos! 5 09-18-2010 03:27 PM
When are we supposed to be able to buy Polaroid film again? jct us101 Non-Pentax Cameras: Canon, Nikon, etc. 10 04-08-2010 12:36 PM
is the k10 supposed to shake... Deiberson Pentax DSLR Discussion 2 02-09-2010 03:03 PM
Sensor cleaning > Sensor Swab > void warranty? Twinky Pentax DSLR Discussion 2 07-28-2007 01:10 AM



All times are GMT -7. The time now is 01:53 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