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09-29-2010, 02:13 AM   #16
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Thank you for the excellent preview!

09-29-2010, 02:28 AM   #17
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Still confused by AF...

At this point I think it is safe to say that at least on SDM the SDM-motor does not turn any faster.
But there there is more to "fast AF, than just the in-lens-AF motor. Yesterday I played a bit with K-7 and Tamron 18-250 in relative low light.... rough focus was about half the AF. That time was almost doubled by the final corrections. Moreover, for example, without moving lens on another sbject, if trying a second shot (same object, same distance) AF aain did a few adjustments.
If that can be speeded up ....

Also, SR "kick-in' time???
09-29-2010, 02:54 AM   #18
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had a go too

Well I was also one of the lucky ones to make it to Cologne and to be able to try out the K-5 hands on. I had the 18-135 and the 60-250 on it and was very impressed by both - speed of AF and monitor (enlarged) quality of the high ISOs.

(I found the ISO 51,200 better than the good old Scotch 1000 ISO slidefilm...)

My current Pentax is a K10D so the differences will be much more pronounced for me than perhaps somebody more familiar with the K-x or the K-7 - but I have made up my mind to order as soon as the prices get to a real life value.
09-29-2010, 04:06 AM - 1 Like   #19
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QuoteOriginally posted by janneman Quote
But there there is more to "fast AF, than just the in-lens-AF motor. Yesterday I played a bit with K-7 and Tamron 18-250 in relative low light.... rough focus was about half the AF. That time was almost doubled by the final corrections. Moreover, for example, without moving lens on another sbject, if trying a second shot (same object, same distance) AF aain did a few adjustments. [...]
Also, SR "kick-in' time???
janneman,
you're right and I hope I wrote nothing else in the article.

The problem was that with e.g., a DA*16-50, the focus on both K-5 and K-7 was almost instant in the office-alike Pentax business area lighting (if the lens was only defocussed a bit). It was then impossible to say which one beeped or triggered faster.

Visually, I got the impression that the K-5 started to focus faster and also locked faster. Maybe, the difference I saw was significant actually. But we talk about ms differences jugded with the naked eye here. So, maybe I saw nothing.

So, a real benchmark where focus times can be measured with ms accuracy must be made. And another one in low light. And accuracy should be measured too as it is often ignored by magazine reports. AF.C is another topic. As is single image AF.S or AF.C accuracy for a moving subject...

For me, the real difference is the AF sensor measurement integration time. It is unknown (except I saw a few bits about it in the pre-production camera EXIF fields). If this time is small, focus on fast moving subjects is possible (even if it then moves out of focus -- at least with trigger priority and maybe prediction, the result with not too thin DoF should still be usable). If this time is large, focus can't be measured because it acts as if the subject would be blurred or noisy. Like AF becomes impossible freehand at too long focal lengths or in very low light. The AF then stalls and the camera won't trigger anymore.

So, with fixed subject contrast and illumination, there should be a limit for maximum subject speed (magnification change speed actually) at which AF stops to work. If this can be measured (together with the latency between AF measurement and photo taken), we may have a good characterization of an AF system. Much more meaningful than all the common trigger latency tests (200ms vs. 300ms etc.).


Last edited by falconeye; 09-29-2010 at 04:19 AM.
09-29-2010, 04:48 AM   #20
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Good writing falconeye, I enjoyed the article and the iso 100 image
09-29-2010, 05:18 AM   #21
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QuoteOriginally posted by falconeye Quote
janneman,
you're right .
I always like to hear that
09-29-2010, 05:26 AM   #22
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great writeup, falk. thanks.

i also wonder as you noted in your post-photokina section, "Where is Pentax headed?"
who will they cater to now and for the immediate and near future?

i guess if one doesn't need to move-up stream, Pentax would be good, but if one desires to go beyond the k5 level cameras, they have to look elsewhere.

will pentax pull an olympus 2 years from now?
that's probably a bigger reason to stay or go, not much on the current level of product as the kr/k5 looks very good.
09-29-2010, 05:30 AM   #23
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QuoteOriginally posted by raz Quote
Good writing falconeye, I enjoyed the article and the iso 100 image
Thanks.
QuoteOriginally posted by janneman Quote
I always like to hear that
I forgot to say ... I reported about the SR kick-in time in the article.

09-29-2010, 05:55 AM   #24
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QuoteOriginally posted by falconeye Quote

Don't miss the exciting news. Moreover, I tried to answer as many questions I received as possible in the report and to skip as much redundant info as possible too.
[/LIST]Enjoy!

What about AA filter? Weak, strong? Close to K-x or K10D?
09-29-2010, 06:30 AM   #25
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Great write-up, Falk. Nice to hear Pentax news from a Pentaxian!

The first hands-on I saw was over at Engadget, but once they figured out it wasn't a Canikon and it also wouldn't play Super Mario Brothers they lost interest.

Your insight and depth of coverage was a refreshing change, answering more questions than I would've thought to ask. Thanks!

It's also made me even more excited to get my hands on a K-5!
09-29-2010, 06:44 AM   #26
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Good to read your preview. I'm very waiting for the 645D report.
09-29-2010, 07:03 AM   #27
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Wow, thanks for all the detailed information. For a consumer that's research you can't buy...

I'm excited to see the production models getting tested and the AF speed. Although I'm happy with my K-7 for now, I can see wanting the K-5 more and more as they proliferate through the market.

Thanks.
09-29-2010, 08:27 AM   #28
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QuoteOriginally posted by falconeye Quote
Teleconverters:

Pentax showed its 1.4x autofocus teleconverter at Photokina 2 years ago. It has disappeared. I asked what happened to it. The response I obtained was hard to accept: Pentax Germany requests production of the teleconverter but Japan denies saying that teleconverters aren't required anymore in the digital age. Pentax Germany tried to explain that a digital magnification may actually have a negative impact on image quality (as we all know) but obviously it did not help much. What shall I say...?

To say honest, the fall of resolution with TC is not above 8-10%. If you have good lenses - it's not a problem at all.
Strange explanation from HOYA.... All brands offer several TC. 1.4 x, 1.7x and 2.0 x with price not above 450 USD.

Last edited by ogl; 09-29-2010 at 08:34 AM.
09-29-2010, 08:57 AM   #29
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QuoteOriginally posted by falconeye Quote
The problem was that with e.g., a DA*16-50, the focus on both K-5 and K-7 was almost instant in the office-alike Pentax business area lighting (if the lens was only defocussed a bit). It was then impossible to say which one beeped or triggered faster.


Really? My K-7 with my DA* 16-50/2.8 focus relatively slowly but the K-7 is very fast with all my screwdrive lenses....
09-29-2010, 09:27 AM   #30
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QuoteOriginally posted by JohnBee Quote
I can send you the file if you still need it.

Thanks for the offer, Falk.
This will likely cause my ISP to send me an error message because of the file size.
Let's just forget about it and I will continue enjoying your presentations right here!
Cheers.

JP


I'm pretty hyped about getting one!
I just hope the new SD card format can squeeze a few more RAW frames out of the continuous shooting buffer :/
I had to enter a few more words ... message was "too short"
JP
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