New K20D - DA* Zooms - Slow Focus ???


Classvino

Link Posted 25/02/2009 - 03:01
OK - after buying a K20D to replace my K10D (which had a broken LCD screen) I've had a funny thing happenning...

My DA* zoom (either one) seems to, when you first turn the camera on, move so slowly as to seem like it's not actually focusing. The first time this happenned, I switched to manual focus and took the shot. It was a grab shot, and I took several with some minor focus adjustments and switched the camera off, promptly forgetting about the slow focus...

The second time, I didn't switch to manual focus, and instead relied on the clutch and manual focused anyway, and took the shot. However, I started playing with things to see what was happenning... After rotating the focus back and forth several times, it suddenly started working as if nothing had ever been wrong. But after switching it off, letting it sit for a bit and then re-trying, it did it again... and does regularly, but not consistently.

Admittedly, it's cold here (-15 deg C - it's February in Canada after all) but I don't think that's the issue - the camera didn't feel especially cold or anything, it had only sat in the car for a bit while the car was warming up...

What's goin' on? Any theories? Happenned to anyone else?

Jamie
--------------
MZ-6,K10D,K20D,Grip,DA*Zooms,DA 18-55-200 Kit,FA50,1.7TC,AFZ360
For Saleentax FA28-90,FA100-300,Sigma EX28-80,DC18-200,
Makinon 500mm Mirror
Last Edited by Classvino on 25/02/2009 - 03:02

johnriley

Link Posted 25/02/2009 - 08:50
Brrr, you don't think minus 15 is cold? That could be the problem - nothing else in particular springs to mind.
Best regards, John

Mike-P

Link Posted 25/02/2009 - 09:15
Classvino wrote:


Admittedly, it's cold here (it's February in Canada after all)
Jamie

It's Febuary here in Spain as well

Seriously, I would think -15 would certainly cause a problem or two.

Saying that, if it didn't happen with your K10D then maybe the cold is not such a problem.
No equipment list here but thanks for taking an interest. My Flickr
Last Edited by Mike-P on 25/02/2009 - 09:17

MattMatic

Link Posted 25/02/2009 - 12:04
I did think my DA17-70 (which is SDM) focused more slowly in the cold snap we had - but that wasn't -15! Haven't managed to see it doing the same thing again.
Matt
http://www.mattmatic.co.uk
(For gallery, tips and links)

Clarky

Link Posted 25/02/2009 - 21:09
Might it have something to do with the battery power. extreme cold does affect batteries so the cold may be restricting the battery output,

-15 I didn't know it could get that cold. How do you live in that.

note to self: don't take brass monkey's with you if ever traveling in Canada
Camera:|K-7|
Pentax Lenses:|DA12-24/f4 ED AL|DA35Ltd Macro|FA31Ltd|FA77Ltd|FA50/1.4|F70-210|FA20-35 f4/AL|A*200/f4 Macro ED|A50/1.7|A50 Macro f2.8|1.7xAF adapter|
Voigtlander|125/f2.5SL Macro APO Lanthar|
Sigma Lenses:|EX DG 100-300 f4|2X & 1.4X TC|
Flashes:|AF540FGZx2|RingFlash AF160FC|

Kenty

Link Posted 25/02/2009 - 22:26
I have a K10D with an 18-250 lens. I recently used it at dawn in Scotland when the temperature was -10c. All worked OK but I had a fully charged battery and when not using the camera put the battery in my trouser pocket to keep it warm. A non Pentax battery I use as a spare really struggled in the cold. (I've learnt a lesson there!)

So it could be a battery problem with your K20D.
On a dark desert highway, cool Pentax K5 in my hand.
My Kit
K5 & 18-55 Kit lens, K7, Pentax 18-250mm lens, Sigma 10-20mm lens, Sigma 105mm Macro lens, Pentax 50mm 1.7 lens, Cokin P Series Filters

Unlocker

Link Posted 26/02/2009 - 04:53
Have had this problem with my 50-135, and it was not in the cold, it also squeaks a bit occassionaly!

We had the 16-50 out in Chicago on Friday morning at -13c with no problems.

Not sure if this helps, but do know that it is not only the cold that can cause the problem!

WebsiteBlogGearTwitterFacebook

Classvino

Link Posted 27/02/2009 - 01:31
Unlocker wrote:
Have had this problem with my 50-135, and it was not in the cold, it also squeaks a bit occasionally!

We had the 16-50 out in Chicago on Friday morning at -13c with no problems.

Not sure if this helps, but do know that it is not only the cold that can cause the problem!

I'm inclined to think it wasn't the cold, since it works fine sometimes in the cold... And, it wasn't the batteries. We're used to batteries performing poorly when cold - though the temperature was -15 outside, the camera was nowhere near that cold as it had been in the house, and in the warming-up car for about 10 minutes, by which time the interior temp of the car was probably +15 or so, so the batteries shouldn't even have dropped below +10 or so...

I'm also occasionally getting the squeaking Unlocker mentions...

I'll keep a close eye on it...



John, Matt, Pete (and all you other warm-weather sissies ) :

-15 isn't unnormal, and this is southern Ontario - When I lived in Northern Ontario (about 600km north of here) it was -45 for 7 or 8 mornings in a row that winter, and usually averaged about -25 during the day... Not sure what it was at night, it was too cold to go out anyway... That's why I'm way "down here" in the south now

And there's a lot more Canada north of that...

Jamie
--------------
MZ-6,K10D,K20D,Grip,DA*Zooms,DA 18-55-200 Kit,FA50,1.7TC,AFZ360
For Saleentax FA28-90,FA100-300,Sigma EX28-80,DC18-200,
Makinon 500mm Mirror

Clarky

Link Posted 27/02/2009 - 04:34
My DA 50-135 is bullet proof, Literally, Shot with paintballs and its fallen from a top bunk, and still going strong.
I haven't experienced any of those symptoms you describe.
Camera:|K-7|
Pentax Lenses:|DA12-24/f4 ED AL|DA35Ltd Macro|FA31Ltd|FA77Ltd|FA50/1.4|F70-210|FA20-35 f4/AL|A*200/f4 Macro ED|A50/1.7|A50 Macro f2.8|1.7xAF adapter|
Voigtlander|125/f2.5SL Macro APO Lanthar|
Sigma Lenses:|EX DG 100-300 f4|2X & 1.4X TC|
Flashes:|AF540FGZx2|RingFlash AF160FC|
Add a Comment
You must be registered or logged-in to comment.