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07-06-2016, 07:00 AM   #76
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QuoteOriginally posted by tomO2013 Quote
I originally raised the thread here about the focus behaviour with focus release and shutter release priority in AFS mode - effectively in lower light the camera will snap quickly to in-focus, but does not confirm the red indicator without a delay and thus gives the impression of slow focus. Back button AF or shutter release priority looks to fix this.
I'm glad dpreview also commented on this behaviour as I feel it is a defect that could be easily rectified by a firmware update.

I feel that defects like this need to be squashed earlier in the development phase as Ricoh is already on the back foot relative to market share. Unfortunately despite SR, astrophotography, dynamic range , pixel shift and all that good stuff, at the end of the day consistent reliable AF with good glass is key for working photographers.

I did not buy into Pentax with the view of using it exclusively for landscape. I bought in knowing that it's AF was not quite as good as Nikon, Canon, but because I felt (having tried a prototype) that it should be good enough for wedding work, run and good portraiture etc... this has turned out to be mostly true depending on the lens attached.

I personally enjoy the camera stores reviews best, finding both Jordan and Chris to be honest, down to earth guys who just love cameras and give a truthful opinion.
Their comment and demonstration of the K1 AFS and AFC performance is to my mind, spot on with respect to similar behaviour I've experienced in the field with certain lenses.

Having said that I've also experienced unacceptably bad AFC and AFS performance with the FA limited primes and this is a problem for me as these are supposed to be the Pentax Top Gun of lenses. Right now I'm feeling a bit like Maverick after Goose dies, I'm reluctant to engage the FA Primes for wedding work.

Consider the attached graphs for the FA Limited...
Test setup:
- Camera locked down on a tripod. lens align mark iv on table mount locked down. Both in perfect alignment via the central dot alignment tool.
- Camera is using center spot focus in AFS and focus priority (with the exception of the FA77 where i tried release priority but confirmed actual focus before releasing the shutter).
- Focal distance used with each lens test was taken at X25 or X50 the recommended focal distance as prescribed by Michael Tapes depending on the lens used.
- camera was fired with remote IR receiver with 2 second delay
- between each AF adjustment, I put the camera in to manual focus and set the camera to infinity stop. Place it back into automatic mode and then back button focus confirm and finally manually trigger the shutter with the IR trigger. This is to force the camera to refocus after each adjustment in a some what real world scenario (going from infinity to the point of focus).

Results (attached PDF's and graphs):
- Not simply bad back focus with the FA Limited's that need correction but also erratic focus e.g. on a number of repeat tests intermediary adjustment values would spike. I've performed each test a number of times to confirm what I am seeing. For the most part I would expect the graphed results to tend linearly towards the actual correct focus plane as the adjustment values increase/decrease.
- In the field I've found that near focus after the recommended adjustment is much better - not dependably accurate, but better. However mid to infinity is a crap shoot at wider apertures (up to F4).
- Some of this glass focus more precise/accurate on backup K3ii.

I've attached graphs for viewing here in case there is something drastic that I have missed.

This is frustrating for me as when focus hits, the rendering is sublime from all 3. Really really gorgeous.
However I had intended these to back up zooms for lower light event work and I am nervous to trust them.
I have noticed that the DFA zooms perform a lot better or at least as well as I remember the D810 in AFS when using back button AF.
However in AFC, it's not in the same ballpark. I'm prepared to put the time in to get results akin to what Barry Pearson gets with his K1 (fantastic AFC) - I do think there is a significant learning investment warranted on my part but that it is possible that there is a faulty batch of K1's with respect to screw drive lenses.

I'd love to see somebody elses focus tune results with the same FA Limited lineup.
I spent a couple hours trying to fine tune my FA 50 1.4 for single point auto-focus and could never get it to work properly at all distances. Then I tried the 9 point cluster and most problems went away. It focuses on what I aim at. However, because the camera has some choice, it won't always choose the exact spot I want, so I have to pay attention to what focus points engage. Overall I'm happy, but if they can get that single point working better in firmware, awesome. Later today I'm renting the 28-105 and I'll see how it does with a modern lens.

07-06-2016, 07:39 AM   #77
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QuoteOriginally posted by RonHendriks1966 Quote
Overhere it's 1999 euro and for that I can also buy a D750 that is blasingly fast in auto focus.
Set it to single centre-point AF like DPR used and see if it works any different from the K-1.
07-06-2016, 07:56 AM   #78
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QuoteOriginally posted by Dan Rentea Quote
But Ricoh does have such a photographer? Where are the Pentax ambassador photographs? I understand that some of the online reviews are biased when comes to Af performance, but I expected from Ricoh to publish some ambassadors photographs...
First, there can be comments on Pentax K1 AF performance from everybody not having used a Pentax K1, but it is very subjective since you rely on review and what you think of Pentax AF for whatever reason. I do have a Pentax K1 with DFA24-70 and DFA150-450, and I wouldn't say that it is 100% good, however, there is no way I can believe the AF test results of DPReview which is way off the actual AF perf. that I observe from my copy of the K1. I've also used a D750. While K1 AF can be more hesitating at times (let's say 5% of the AF runs), 95% of AF runs it's as good as the D750 I've used. In short, I agree that Pentax K1 is not as robust as Nikon D750, but since I own the K1, I have shot 5000 frames from birding to horse racing and I never had any poor results like presented by DPReview. DPReview could still say that Pentax K1 AF is inferior to Canon/Nikon, but saying that they get 85% out of focus in tracking indicates a test problem that can't be generalized to how all K1 copies behave.

If I'd rank DSLR AF performance from best to worse, it would be in this way:
1) Nikon D5/D500
2) Canon 1Dx
3) Nikon D750/810
4) Canon 5DII/7DII
5) Pentax K1/K3
6) Nikon D610/D7200
7) Canon 6D/70D

Last edited by biz-engineer; 07-06-2016 at 08:07 AM.
07-06-2016, 08:14 AM   #79
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QuoteOriginally posted by clackers Quote
But don't DPR have anyone who knows how to take a photograph, Ron?
QuoteOriginally posted by Dan Rentea Quote
But Ricoh does have such a photographer? Where are the Pentax ambassador photographs? I understand that some of the online reviews are biased when comes to Af performance, but I expected from Ricoh to publish some ambassadors photographs...
At dpr they do a test. It is not their job to fill a portfolio with images. The test looks to me as something a camera in that price range could do. I'm not to surprised that the Pentax af module is still not capabele of following a biker going towards the camera. One can do that and even help the camera with internal settings in the menu, but this is more something for doing specialty images. I don't expect any reviewers, nor most users to be able to this. This is something that the camera could do if the hardware was up to the task, it's a moderate speed biker.



I'm not to impressed with how Ricoh-Imaging is working with ambassadors, or how they present images to sell their camera's. Maybe I missed something, but in general they are not making it better for the camera to sell.

07-06-2016, 08:34 AM   #80
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Seems like the bike test would be easy test for the Forum or Pentax to perform and publish the results. What an opportunity for good publicity - maybe.
07-06-2016, 08:36 AM   #81
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QuoteOriginally posted by RockvilleBob Quote
Seems like the bike test would be easy test for the Forum or Pentax to perform and publish the results. What an opportunity for good publicity - maybe
be interesting to try it in various lighting conditions, too, to see how much difference that makes
07-06-2016, 08:40 AM   #82
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I am rather underwhelmed at dpr being unable to do even an amateur level test.

The really have a track record of underperforming, this now only being the latest dpr failure.

Let's remember how their lack of understanding screwed up the whole pixel shift "test" and they had to withdraw it.

I mean, how low must you get to not even understand
a) if you want to compare something you have to use the exact same test for all three cameras (they did not)
b) if you want to autofocus something, point the camera at it inclusing the existig af sensors.

That is to be expected even from an beginning amateur and here we are facing people who get money for this.
07-06-2016, 08:41 AM   #83
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QuoteOriginally posted by RonHendriks1966 Quote
I'm not to impressed with how Ricoh-Imaging is working with ambassadors, or how they present images to sell their camera's. Maybe I missed something, but in general they are not making it better for the camera to sell.
Still sore about the fact?
What would you expect of a camera (any brand)?
Focus on a subject that is out of any of its AF points?
You want miracles?

ps;
you still own a camera?

07-06-2016, 08:42 AM   #84
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Silver - because there is a better camera in the category. Oh wait - no there isn't.
07-06-2016, 08:45 AM   #85
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It's in the wrong category anyway.. Should be in the D810 5DMK II a7 R II category.
07-06-2016, 09:28 AM - 1 Like   #86
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QuoteOriginally posted by monochrome Quote
The defined parameters for, and execution of this review demonstrate either pathological incompetence or intentional malicious intent.
Quoting myself here, I just ordered the 28-105, which should arrive in time to shoot a hockey game this weekend. I plan to evaluate 4 settings combinations on my K-1, one for each quarter. I shall offer a real-world report here.
07-06-2016, 09:30 AM   #87
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QuoteOriginally posted by RockvilleBob Quote
Seems like the bike test would be easy test for the Forum or Pentax to perform and publish the results. What an opportunity for good publicity - maybe.
Yes, honestly, I'm really curious about DPR results, I bet I can do a lot better, and as soon as I get the opportunity I'd do a "bike test" fill the camera buffer and post the results.
07-06-2016, 09:44 AM   #88
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QuoteOriginally posted by monochrome Quote
Quoting myself here, I just ordered the 28-105, which should arrive in time to shoot a hockey game this weekend. I plan to evaluate 4 settings combinations on my K-1, one for each quarter. I shall offer a real-world report here.
What kind of sport is hockey in your world?
07-06-2016, 10:36 AM   #89
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QuoteOriginally posted by RonHendriks1966 Quote
What kind of sport is hockey in your world?
on ice, otherwise you wouldn't have 4 quarters
07-06-2016, 10:39 AM   #90
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QuoteOriginally posted by monochrome Quote
Quoting myself here, I just ordered the 28-105, which should arrive in time to shoot a hockey game this weekend. I plan to evaluate 4 settings combinations on my K-1, one for each quarter. I shall offer a real-world report here.
I would be interested in this test as long as you are using the lenses wide open or near wide open. when using something like f8 it is more a test of the shutter speed then it is about focus tracking

Randy
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