Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-08-2009, 03:14 AM   #1
Inactive Account




Join Date: Oct 2009
Location: Groningen
Posts: 3
Reaching the limits (AF) of the K10d - K20 or K7

I am really frustrated with my Pentax focus at the moment. The AF was accurate enough for me during my landscape-, macro- and product photography, but has been more than frustrating during my fashion photography lately. Working with small DOF, off-centre compositions and sometime low light conditions I find the OOF nrs a bit too high lately. I tried to abandon focus and recompose but the outer focus points are just to inaccurate to get good results. I keep defending Pentax to all my C & N friends, but question my self if i should.... Yesterday was the last drop. Needed to make catwalk pictures in a bar. The light was TOO low (800iso, 1/25s, f4). Focus locked in like 25% of the cases with 50% sharp. My friend (5d II) had also some troubles but far better results.

I heard about the great AF-improvement of the K7, but don't have the money for the switch, especially because of the grip being an unbelievable 250,- euro's.

So what about the K20d, I read that it's the same system, but I also read about improvements. Would switching to the K20d would solve part of my problems. I would like to hear form swithed users (k10 -> k20, K20 -> K7, k10 - k7).

10-08-2009, 06:58 AM   #2
Veteran Member
filorp's Avatar

Join Date: Jun 2008
Location: Aberdeen Scotland
Photos: Gallery | Albums
Posts: 389
i have switched from k10 - to k20 early this year on k10 only 16-50 worked some haw forget about limiteds. O! I was workink as night club/disco photographer, the worse light condition you can imagine: sometimes pitch black suddenly laser light and colourfull disco lights sweeping dance floor.... for 200 pict i had to chock out about 15-20. When i have switched to k20 stitation changed noticable even with limiteds, but with 16-50 and especially with 17-70 i had almost always spot on. 77limited became my 100% shooter, 43ltd a little bit worse (it isn't good for tunsten light) the speed of the af doesn't disturbing me to much - framing taking me so long time that AF speed is really irrelevant...
10-08-2009, 07:05 AM   #3
Senior Member
insulinguy's Avatar

Join Date: Aug 2009
Location: Fort Worth, TX
Photos: Gallery | Albums
Posts: 134
i understand some of the complaints that come out regarding pentax AF system - but is it really THAT hard to just manual focus? ive never once had a photo that wasnt in focus when i did it myself...just saying- because its there doesnt mean you have to use it...
10-08-2009, 07:18 AM   #4
Inactive Account




Join Date: Oct 2008
Location: Rochester, NY
Photos: Gallery | Albums
Posts: 119
Depends on your needs. If you're doing a lot of high speed action work, you'd want the AF to almost be instantaneous even between frames. Certainly not a deal breaker for me right now, and stopping down can certainly help, but I can see how someone would be frustrated.

I've had my share of cursing when AF wouldn't lock or not being able to focus fast enough on energetic children or puppies.

10-08-2009, 07:38 AM   #5
Veteran Member
heliphoto's Avatar

Join Date: May 2008
Location: Region 5
Photos: Gallery
Posts: 2,540
In all conditions, my K-7 blows the doors off of the K20D in regard to focusing - especially in low light within range of the focusing assist light... Blows Doors! That said, I like the high ISO results much better from the K20D than the K-7. If I could have the high ISO performance of the old camera (!) with the AF of the new camera, I wouldn't be looking at Canon so hard right now...
10-08-2009, 08:00 AM   #6
Inactive Account




Join Date: Oct 2009
Location: Groningen
Posts: 3
Original Poster
Thanx.

It is mostly the accurate of non centre focus points I am interested in. I don't do sports so I should not be fast, but accurate. Still, I would like to lock into focus within the 2 seconds the model poses at the cat walk.
10-08-2009, 08:26 AM   #7
Veteran Member




Join Date: Jul 2008
Location: Var, South of France
Photos: Albums
Posts: 1,071
Well, I'll do some test, but I have to second Heliphoto : having successively owned the k10, k20 and k7, the latter really blows previous model regarding low-light AF, not only in terms of speed but also on accuracy...

I'll try the off-center points tonight...
10-08-2009, 08:28 AM   #8
Veteran Member
PePe's Avatar

Join Date: Nov 2007
Location: Helsinki, Finland
Photos: Gallery | Albums
Posts: 452
In terms of AF performance the K7 is way ahead of the previous models - with a clear margin. No doubt about this. This also applies to non-SDM/HSM lenses.
High-ISO noise with K7 seems to be at least partly a post-processing issue. Althought the sensor is a derivative of the one used in K20, it seems to require somewhat different settings and procedures, both in terms of colour balance and noise reduction. After using the K7 for a couple of months now, I think I am gradually finding the correct settings.

10-08-2009, 08:46 AM   #9
Site Supporter
opiedog's Avatar

Join Date: Jan 2008
Location: NC
Posts: 787
Km/K2000?

i switched to the k2000 from a k10. the k2000/km's AF is sooo much better, faster even in low light compared to the all the previous pentax dslrs except the K7.


i've used it for my daughters softball and soccer games. many times with low light and my k2000 with sigma 50-150 f2.8 has been more than adequate.

it's a beginners camera though, but who says it can't be used on the cat walk?
10-08-2009, 01:22 PM   #10
Pentaxian
Marc Sabatella's Avatar

Join Date: Sep 2006
Location: Denver, CO
Photos: Gallery
Posts: 10,686
QuoteOriginally posted by heliphoto Quote
In all conditions, my K-7 blows the doors off of the K20D in regard to focusing - especially in low light within range of the focusing assist light... Blows Doors! That said, I like the high ISO results much better from the K20D than the K-7. If I could have the high ISO performance of the old camera (!) with the AF of the new camera, I wouldn't be looking at Canon so hard right now...
I assume you are aware of this, but in case not - basically the only reason the K20D has less noise at high ISO is that it does more NR in camera. This has been measured empirically. You should be able to match its results with the K-7 by doing the equivalent NR in PP.
10-08-2009, 01:42 PM   #11
Veteran Member
heliphoto's Avatar

Join Date: May 2008
Location: Region 5
Photos: Gallery
Posts: 2,540
QuoteOriginally posted by Marc Sabatella Quote
I assume you are aware of this, but in case not - basically the only reason the K20D has less noise at high ISO is that it does more NR in camera. This has been measured empirically. You should be able to match its results with the K-7 by doing the equivalent NR in PP.
Thanks Marc - I had read something like that, and I appreciate the info... I think perhaps my problem is that I shoot exclusively RAW, and until now have relied on Lightroom 1.4 for all my processing - perhaps it's time I try a different NR software (first I see if an upgrade to Lr 2.* will handle the noise better - just gotta download the demo...) I love the K-7, but I'm really hating the results I get above around ISO 640 or so. It's not just noise, but the noise seems blocky - like the noise "grain" is four pixels big rather than one, and these large grains are scattered here and there rather than continuous. When I crank the NR in Lr it looks pretty good for the most part, but there are these blocky artifacts here and there... I'll look into it more - I'm not giving up yet .
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!
af, camera, dslr, focus, k10, k20, k20d, k7, light, pentax, photography, results
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Black & White Reaching VaughnA Post Your Photos! 7 06-27-2010 05:40 PM
Landscape Reaching Out goddo31 Post Your Photos! 2 11-25-2009 07:05 PM
Marketplace off limits? TourDeForce Site Suggestions and Help 10 07-31-2009 07:24 PM
Theoretical limits... frith Troubleshooting and Beginner Help 3 06-03-2009 06:33 AM



All times are GMT -7. The time now is 05:42 PM. | See also: NikonForums.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