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04-19-2016, 01:27 AM   #1081
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QuoteOriginally posted by kenspo Quote
It is fast on K-3II, but faster on K-1 when i tested. The 70-200 is made specific for the K-1..Why he said that, i have no clue Of course, not D5 fast, but very fast in Pentax terms..hehe
But as fast as FA135

04-19-2016, 01:51 AM   #1082
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Never tried that, since i always have to use the newest stuff But i have used the K-1 and 70-200 combo!
04-19-2016, 04:12 AM   #1083
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Like ClassA, i hardly can believe different speeds with the same AF engine driven lens, according to the body used.

What i can testify, is that DFA*70-200's engine is slower than DA16-85's, that goes as fast on my K20D as on my K-3.

Whilst hunting from zero to 3 or 4 steps depends for sure on the body, and also AF-C performance.
04-19-2016, 04:25 AM   #1084
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Test lenses on the cameras they are made for. THEN you can complain or cheer

04-19-2016, 06:02 AM   #1085
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QuoteOriginally posted by Winder Quote
I have seriously thought about returning my D-FA* 70-200mm after using it on my K-3. Not fast at all on the K-3.
Well, the AF on cameras like the Nikon D4 isn't that fast actually, it is the lenses which do matter for action and their AF motors which do matter and are fast, like 70-200/2.8 or 500/4 or 600/4.

In that regard, I would be surprised to learn that Pentax hasn't put a competitively fast AF motor into their new DFA* 70-200/2.8. Kind of defeats its reason to exist.

Do we have *any* specifications about the kind of AF motor Pentax put in the DFA*70-200/2.8? Like ring-type, torque etc.?

At http://www.bhphotovideo.com/c/product/1117718-REG/pentax_21330_hd_pentax_d_fa.html , I read the lens AF has a DC motor. Well, that would be a bummer, not adequate for a sports lens IMHO. Same says http://us.ricoh-imaging.com/product/d-fa/hd-pentax-d-fa70-200mm-f2-8ed-dc-aw-wcase

Last edited by falconeye; 04-19-2016 at 06:08 AM.
04-19-2016, 06:31 AM   #1086
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To date, DC has been the only alternative developped by RI to Super Doomed Motors ... that are still included in recent 645 lenses.


Only K-mount FF Tamron rebadges get some new "SDM" engine, but not that from Ricoh, nor faster than DC engines.

Last edited by Zygonyx; 04-19-2016 at 06:39 AM.
04-19-2016, 06:41 AM   #1087
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QuoteOriginally posted by falconeye Quote
Like ring-type
asahi-man said a while ago that it was ring-type.
But I have never seen a diagram.

The DFA 70-200 lens engineers (Makoto Iikawa and Masakazu Saori) talk about the 70-200 design process here in one of the early 'Pentax Story' app presentations (see the section under 'Engineers Interview'):

If anyone can read Japanese, it would be great if they could let us know if the Pentax engineers provide any information about the lens motor.

04-19-2016, 08:15 AM   #1088
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QuoteOriginally posted by rawr Quote
asahi-man said a while ago that it was ring-type.
But I have never seen a diagram.

The DFA 70-200 lens engineers (Makoto Iikawa and Masakazu Saori) talk about the 70-200 design process here in one of the early 'Pentax Story' app presentations
Thanks for the link, interesting resource (although I can't read the Japanese).

I think the DC motor is confirmed by the fact that it is in the lens' name and also the official specs. AFAIK, ring-type motors are all ultrasonic (piezo), so this would be off the table. There are non-ring type ultrasonic motors (like Pentax SWM) which a DC motor could outperform though.

A DC motor would have to have sufficient size and a proper gear box to be powerful enough to compete with ring-type motors. That's why I asked if we know anything about the motor, spec-wise.
04-19-2016, 12:56 PM - 1 Like   #1089
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Anyone just needs to google "brushless ring motor" or "brushless DC motor" to find ring type DC motors with enough torque to drive vehicles.
For samples:
http://www.thingap.com/wp-content/uploads/2013/05/ThinGap-advanced-brushless-motors.jpg
https://www.aerotech.com/product-catalog/motors/rotary-motors/s-series.aspx
Products | ThinGap high power density brushless motors
04-19-2016, 01:13 PM - 1 Like   #1090
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QuoteOriginally posted by beholder3 Quote
Anyone just needs to google "brushless ring motor" or "brushless DC motor" to find ring type DC motors with enough torque to drive vehicles.
For samples:
http://www.thingap.com/wp-content/uploads/2013/05/ThinGap-advanced-brushless-motors.jpg
https://www.aerotech.com/product-catalog/motors/rotary-motors/s-series.aspx
Products | ThinGap high power density brushless motors
asahi man showed a photo of exactly this type (Aerotech) of brushless DC gearless torque motor in an argumentative post about Pentax DC focus motor patents.

Post

Kollmorgen DC Torque Motor


Last edited by monochrome; 04-19-2016 at 01:24 PM.
04-19-2016, 01:25 PM   #1091
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A eagerly wait to have my new and definite try with K-1 and that bloody zoom-lens.
04-19-2016, 04:19 PM   #1092
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QuoteOriginally posted by rawr Quote
If anyone can read Japanese,
No need
There is an English web version of the '70-200 Pentax story' on the web page for the lens on RI Japan, including the 'Engineers Interview'.

HD PENTAX-D FA★ 70-200mmF2.8ED DC AW | RICOH IMAGING

Lots of text about lens ergonomics, coatings, AW etc throughout the whole site. No mention at all of AF motor, AF speed.
04-19-2016, 04:51 PM   #1093
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Just checked my order at B&H and the website is now saying: "Expected availability: Beginning of May 2016" Not sure if that is really a change or just reality since they will be closed for the Passover holiday until May 2nd.

Leaving on a coast trip on 5 May so this is really getting too close..........

---------- Post added 04-19-16 at 04:53 PM ----------

Amazon says "item will be released on April 25th". Anyone think I should cancel the B&H order and order from Amazon?

---------- Post added 04-19-16 at 04:56 PM ----------

Adorama now says: "Manufacturer will start shipping this item on 05/15/2016"
04-19-2016, 04:59 PM   #1094
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QuoteOriginally posted by jatrax Quote
Just checked my order at B&H and the website is now saying: "Expected availability: Beginning of May 2016" Not sure if that is really a change or just reality since they will be closed for the Passover holiday until May 2nd.
I don't suppose we would get lucky and the listed availability is for new orders going forward?
04-19-2016, 05:05 PM   #1095
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QuoteOriginally posted by jlstrawman Quote
I don't suppose we would get lucky and the listed availability is for new orders going forward?
Doubtful. But I don't think it matters because they are closed April 21 through May 1st. They state no shipping or ordering during that period. Not sure if that means no receiving as well but probably does. So even if RIcoh delivers on the 25th there will be no one there to receive the order.
So unless they ship tomorrow I do not see how they will ship before May 4 or 5........ or later..............
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