Forgot Password
Pentax Camera Forums Home
 

Closed Thread
Show Printable Version Search this Thread
02-06-2011, 12:09 AM   #361
Veteran Member
Christine Tham's Avatar

Join Date: Nov 2008
Location: Sydney, Australia
Photos: Gallery
Posts: 2,269
QuoteOriginally posted by Tommot1965 Quote
no worries..that's well within the parameters of a FF test.....do you mind telling us the build date of your K5...".photo me" will be able to give you this info...just open up a image taken with your K5..then go to manufacturer's notes...
Pentax Model 0x12e76
Manufacture Date 2010-12-09

I'm not sure I kept any of the pictures (I checked focus by using the zoom feature during image playback on the camera), but I will check and if I find any I will post.

Just came back from shooting the bird show at the zoo - mainly to test how well the K-5 can do autofocus in 7fps continuous mode.

I must admit - I was skeptical as to how "improved" the autofocus is over my K10D (which I didn't have any real problems with - have captured plenty of "birds in flight" photos on my K10D successfully)

Results - the autofocus is good (big happy smile on face). Not perfect, but much better than the K10D - the ratio of keepers vs duds are far higher, and I can get long sequences where every single shot of a bird in flight is in focus.

I would say my K-5 with the DA 70mm Ltd is in the same ballpark in terms of AF accuracy as the Canon EOS-1D Mark III. Note I said "ballpark" - the Canon I think still has the edge and of course can shoot at 10fps, but the K10D was nowhere near this level of performance.

Will definitely post some pictures from the bird show (in a new thread) if I get to finish doing the processing ...

02-06-2011, 01:11 AM   #362
Veteran Member
Tommot1965's Avatar

Join Date: Sep 2010
Location: Perth Western Australia
Photos: Gallery | Albums
Posts: 1,026
cheers Christine.....glad your enjoying your K5...

some shots of mine

perth zoo....https://www.pentaxforums.com/forums/post-your-photos/128659-nature-perth-zoo.html


the humble Maggie......https://www.pentaxforums.com/forums/photo-critique/130729-nature-australias-o...ing-drink.html
02-06-2011, 01:57 AM   #363
New Member




Join Date: Jan 2011
Location: Stockholm
Posts: 1
QuoteOriginally posted by Tommot1965 Quote
your K5 and the one other thats been reported , is not typical of the FF suffered by the rest of us..Id suggest that you and the other PF member who has this issue, have a body that's is failing else where to have FF that severe
In my opinion that is what we are talking about: malfunction AF under artificial light, NOT some mm fault at 43 mm focal length near the minimum focus distance which is 0,45m for the 43 mm limited, right? How realistic photographic situations is that? I believe all K5 will focus correct at that distance, mine do easily!

I bet you have this issue too and probably Christine too, but maybe you aren't affected, because you haven't photographed under those circumstances. But this is just a guess, if your bodies are ok, then we probably have a hardware issue here...

I own booth the K5 and the K7 and have run some tests with (18-55mm WR, 21mm limited and the Sigma 30mm 1,4). And I can for sure tell you that what Pentax describes as a Highly responsive and accurate autofocus system with improved focus speed and reliability is only true regarding the speed, but not the reliability. At least in my case during dim light conditions, and obviously many others as well...
02-06-2011, 02:54 AM   #364
Veteran Member
Tommot1965's Avatar

Join Date: Sep 2010
Location: Perth Western Australia
Photos: Gallery | Albums
Posts: 1,026
QuoteOriginally posted by KingBolt Quote
In my opinion that is what we are talking about: malfunction AF under artificial light, NOT some mm fault at 43 mm focal length near the minimum focus distance which is 0,45m for the 43 mm limited, right? How realistic photographic situations is that? I believe all K5 will focus correct at that distance, mine do easily!

I bet you have this issue too and probably Christine too, but maybe you aren't affected, because you haven't photographed under those circumstances. But this is just a guess, if your bodies are ok, then we probably have a hardware issue here...

I own booth the K5 and the K7 and have run some tests with (18-55mm WR, 21mm limited and the Sigma 30mm 1,4). And I can for sure tell you that what Pentax describes as a Highly responsive and accurate autofocus system with improved focus speed and reliability is only true regarding the speed, but not the reliability. At least in my case during dim light conditions, and obviously many others as well...
I agree with that


most haven't seen the issue if shooting at F4 or above, the whole FF issue cant be seen if you don't have a quick enough lenses {f2.8 or lower} to limit DOF to a razzor width.
and shooting torture tests are quite often the only way to spot it....for most!.

I would suggest the if any K5 owners are missing focus by 500mm. then its not the same FF issue as most are reporting.

I've followed this saga since the first post by Bjan.

https://www.pentaxforums.com/forums/pentax-k-5-forum/126234-who-cares-bad-aut...ten-light.html


..and its obvious from the vast amount of data that the FF issue is only seen in EV4 or lower, and at very shallow DOF.

please see here for a test procedure started by Jolepp...

https://www.pentaxforums.com/forums/pentax-k-5-forum/129738-k-5-user-auto-foc...t-results.html

02-06-2011, 04:08 AM   #365
Pentaxian
volley's Avatar

Join Date: Jan 2009
Location: Germany
Photos: Gallery
Posts: 2,387
QuoteOriginally posted by Christine Tham Quote
LOL!

I know it was a spelling mistake, but did I laugh ever!
See, that happens when German's get emotional We are just not designed for that ...
By the way, thank you very much for sharing the results of your tests with the forum. Much appreciated!
02-06-2011, 10:21 AM   #366
Forum Member




Join Date: Jun 2010
Location: Indianapolis
Posts: 83
I have been visiting some of the Nikon forums and it appears there is a lot of discussion about backfockusing with the D7000 under artificial light. Of course, nobody is saying darn Nikon, I am switching to Canon or Pentax, they just send their cameras back for service, typically with limited success. I have to admit I was pretty close to pulling the trigger (SAM's club has the d7000 now) but I am not sure it will be worry-free. Is it possible that the sensor is somehow the problem? I mean, previous Pentax cameras (like my kx) don't have this and the other camera with the same sensor (d7000) has the same issue. I haven't heard anything about the Sony A580 which has the same sensor, but haven't looked much either. Anyone with more technical knowledge to comment?
02-06-2011, 10:40 AM   #367
Pentaxian
gazonk's Avatar

Join Date: Feb 2009
Location: Oslo area, Norway
Photos: Gallery | Albums
Posts: 3,512
QuoteOriginally posted by tbirdas Quote
Is it possible that the sensor is somehow the problem?
The sensor is independent from the AF system, but of course the high resolution makes tolerance levels lower.
02-06-2011, 11:33 AM   #368
Pentaxian
philbaum's Avatar

Join Date: Oct 2007
Location: Port Townsend, Washington State, USA
Posts: 3,659
QuoteOriginally posted by tbirdas Quote
I have been visiting some of the Nikon forums and it appears there is a lot of discussion about backfockusing with the D7000 under artificial light. Of course, nobody is saying darn Nikon, I am switching to Canon or Pentax, they just send their cameras back for service, typically with limited success. I have to admit I was pretty close to pulling the trigger (SAM's club has the d7000 now) but I am not sure it will be worry-free. Is it possible that the sensor is somehow the problem? I mean, previous Pentax cameras (like my kx) don't have this and the other camera with the same sensor (d7000) has the same issue. I haven't heard anything about the Sony A580 which has the same sensor, but haven't looked much either. Anyone with more technical knowledge to comment?
I've noticed the same thing, some pretty mad Nikon D7000 owners judging by the posts. A friend i shoot with has sent me 6 photos he shot of myself and friends at a recent get together, pretty soft results from his new D7000 (indoor shots from a coffee bar)

Definitely appears to be a connection, one guy writing that adjustments only moved the backfocusing to front focusing in sunlight.

02-06-2011, 03:27 PM   #369
Site Supporter




Join Date: Feb 2008
Location: Boston MA
Photos: Gallery | Albums
Posts: 279
I just tried shooting 2 dances last night where it is a bit dim, about 3EV. No tests, just practical usability of the camera I am describing. Many are FF at 30mm F/1.8, making almost all photos useless. I even set the AF adjustment to -10. It is actually embarrassing because it makes me look like I do not know what I am doing. This problem is very clear when you try to do certain type photos. I guess I could reduce the aperture to 2.8 and increase the sensitivity, however, then I loose the nice narrow DOF. I had a K10D before, which under the same circumstances would hunt and focus slowly but at least lock correctly. The K5 locks well, but is consistently FF in these conditions. This is a bit frustrating, since I like the unmatched sensor capabilities, but not the low light focusing.....
02-06-2011, 03:35 PM   #370
Junior Member




Join Date: Jun 2007
Location: Canada
Posts: 49
QuoteOriginally posted by Eric Seavey Quote
I just tried shooting 2 dances last night where it is a bit dim, about 3EV. No tests, just practical usability of the camera I am describing. Many are FF at 30mm F/1.8, making almost all photos useless. I even set the AF adjustment to -10. It is actually embarrassing because it makes me look like I do not know what I am doing. This problem is very clear when you try to do certain type photos. I guess I could reduce the aperture to 2.8 and increase the sensitivity, however, then I loose the nice narrow DOF. I had a K10D before, which under the same circumstances would hunt and focus slowly but at least lock correctly. The K5 locks well, but is consistently FF in these conditions. This is a bit frustrating, since I like the unmatched sensor capabilities, but not the low light focusing.....
Yup. Frustrating,I feel your pain. Sony hit it out of the park with the sensor. Pentax failed to tame the beast.
02-06-2011, 03:51 PM   #371
Veteran Member
Smeggypants's Avatar

Join Date: Sep 2010
Posts: 1,536
QuoteOriginally posted by Zugzwang Quote
Yup. Frustrating,I feel your pain. Sony hit it out of the park with the sensor. Pentax failed to tame the beast.
The sensor is nothing to so with the regular AF system.

In fact the Live View AF, which does of course use the sensor, works perfectly.
02-06-2011, 04:26 PM   #372
Veteran Member
Christine Tham's Avatar

Join Date: Nov 2008
Location: Sydney, Australia
Photos: Gallery
Posts: 2,269
Guys - just a tip.

Regardless of whether the camera is FF or BF, you are not going to get good results taking photos with wide open apertures in low light conditions.

Even if the camera was focusing perfectly, you are likely to get soft photos as the depth of field is so narrow it can't get the entire face in focus.

Trust me, I have wasted lots of shots before learning my lesson on many cameras. I am a slow learner!!!

My advice is: stop down the lens to f4-f5 at a minimum, take advantage of the high ISO capability of the K-5, and take a shot you will be proud of.
02-06-2011, 04:37 PM   #373
Veteran Member
filorp's Avatar

Join Date: Jun 2008
Location: Aberdeen Scotland
Photos: Gallery | Albums
Posts: 389
QuoteOriginally posted by Christine Tham Quote
My advice is: stop down the lens to f4-f5 at a minimum, take advantage of the high ISO capability of the K-5, and take a shot you will be proud of.
Moste portrait/fashion photographers doing it this way, but there is other tribe of photographers who still relies on shollow dof and precisely working af system or manual focusing....

Last edited by filorp; 02-06-2011 at 05:30 PM.
02-06-2011, 04:53 PM - 1 Like   #374
Veteran Member
Christine Tham's Avatar

Join Date: Nov 2008
Location: Sydney, Australia
Photos: Gallery
Posts: 2,269
QuoteOriginally posted by filorp Quote
Moste portrait/fashion photographers doing it this way, but there is other tribe of photographers who still relys on shollow dof and precisely working af system or manual focusing....
No AF system will be reliable in situations where you want razor sharp DOF.

Or to be more precise, I would not trust an AF system to make a decision for me if I am trying to zero in a mm depth DOF type photo. The chances of the crosshair focusing on something other than I wanted is just too high.
02-06-2011, 07:11 PM   #375
Site Supporter




Join Date: Feb 2008
Location: Boston MA
Photos: Gallery | Albums
Posts: 279
Actually, the K5 did focus and lock in the conditions I was shooting in. However, the FF offset ended up being the cause for numerous unsharp photos. Things would be fine if I could change the AF fine adjustment to -20 to -30 or so.

If the type of light really was the problem, than having to manually enter the lighting type so that the AF would work properly using an offset, would be fine with me too. Like a sub menu somewhere where one enters the low lighting type, e.g. Candle/Tungsten/halogen/LED blue/LED green/LED red/Cloudy daylight/sunset day light, Etc.

Just an idea...
Closed Thread

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, issue, k-5, k-5 ii, k-5 iis, k5, pentax k-5, re, thread
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Help! K7 malfunctioning samski_1 Pentax DSLR Discussion 9 07-11-2010 03:24 PM
Probably not relevant or welcome here climbertrev Non-Pentax Cameras: Canon, Nikon, etc. 4 05-24-2010 05:15 AM
camera based sensorcleaning how relevant is it. hein Pentax DSLR Discussion 13 09-13-2009 12:26 PM
Light fluff but news.. sort of jeffkrol Pentax News and Rumors 8 12-30-2008 06:30 PM
Snowflakes... ( artificial ) TrailSeeker Post Your Photos! 0 12-12-2006 08:33 AM



All times are GMT -7. The time now is 09:14 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