Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
06-07-2012, 06:00 AM   #1
Banned




Join Date: Jun 2012
Location: NY/Germany
Posts: 1,183
M-Series Free-Spinning Aperture Ring Repair?

I've located a local shop that has a couple M-series lenses for sale, but two of the ones I'm interested in have aperture rings that spin freely. To clarify, they work fine, but there's no detent anymore- infinitely adjustable and doesn't lock into place.

I'm actually considering buying one of these examples, but I don't know if I can repair the ring or if it even needs repair and I should just shoot with it, as the lens and aperture operate fine.

What is the opinion of this?

06-07-2012, 06:18 AM   #2
Loyal Site Supporter
eddie1960's Avatar

Join Date: Aug 2010
Location: Toronto
Photos: Gallery | Albums
Posts: 12,270
Actually for shooting video these would be better since there would be no noise from adjusting aperture while shooting. I have a couple of m39 and m42 lenses that work this way. as long as the aperture operates i wouldn't worry overly, but I'd beat him down on the price over it since they are obviously not working the way they should.
If I'm not mistaken people sometimes do this to lenses specifically for video. if you had the removed part it could easily be restored
06-07-2012, 06:21 AM   #3
Banned




Join Date: Jun 2012
Location: NY/Germany
Posts: 1,183
Original Poster
Thanks a bunch for that. In fact, I got older FA lenses, rather than current DA equivalents because I do stop down and go back up during video. The only thing is when I do, the clicks are distracting, so it's a great idea you focused on that I didn't even think of. So perhaps these lenses were modded for video use.
06-07-2012, 07:05 AM   #4
Loyal Site Supporter
eddie1960's Avatar

Join Date: Aug 2010
Location: Toronto
Photos: Gallery | Albums
Posts: 12,270
QuoteOriginally posted by snake Quote
Thanks a bunch for that. In fact, I got older FA lenses, rather than current DA equivalents because I do stop down and go back up during video. The only thing is when I do, the clicks are distracting, so it's a great idea you focused on that I didn't even think of. So perhaps these lenses were modded for video use.
A lot of the Russian m42 lenses are like this. I think a lot of people modify Taks this way for use on canon

06-07-2012, 07:07 AM   #5
Banned




Join Date: Jun 2012
Location: NY/Germany
Posts: 1,183
Original Poster
So long as I can get the aperture ring to not drift to often, I think this might be a preferable way to use it. I'll check back with the store or see if I can put o-rings on either side to generate a slight bit of friction if there is some drift.
06-10-2012, 09:23 AM   #6
Banned




Join Date: Jun 2012
Location: NY/Germany
Posts: 1,183
Original Poster
Looks like I'll be getting one such example from ebay, supposedly good condition, for 94 euros shipped. Hopefully it's in otherwise good working order.

Thanks for the help with this. I'm looking forward to seeing how good this M85 f2 is and finding a decent hood for it.

Last edited by snake; 06-10-2012 at 09:33 AM.
06-11-2012, 11:29 AM   #7
Banned




Join Date: Jun 2012
Location: NY/Germany
Posts: 1,183
Original Poster
Sorry, I wanted to get some clarification on how to shoot with this lens, since the ring doesn't stop. I've read about stop-down metering, tried it out on my other lenses (both F.FA) in MF+M mode to get the gist if it. Now the issue is that if the ring moves when I'm trying to meter, then what is one to do?

I've used manual lenses in the past, but on Olympus, and it was relatively straight-forward, simply observing the exposure meter, but it seems a bit less straight forward here with the K-5, or is it?
06-13-2012, 05:56 AM   #8
Banned




Join Date: Jun 2012
Location: NY/Germany
Posts: 1,183
Original Poster
Ok, received the lens and it's really in much better condition than advertised.

I mistakenly posted in the stop-down metering thread about the ring issue-

I can 100% confirm that without the detent ball, the ring does drift during the stopdown metering process. It's worst at f2, when it goes to about f2.4-2.8. Later, there's little movement.

I removed the ring, greased it lightly with a sticky grease, which minimized the drift, though there is still a small amount. The detent ball was there, stuck, and nothing behind it, so it just popped off. I removed it and put it in a safe place, but there was nothing there to hold it in place, oddly.

I'm still trying to figure out how and in what mode to use the lens, as it's not as straight forward as it was on my Olympus e510. Simply, one need only look at the EV meter, adjust, then shoot. Here, I don't seem to have that luxury and I get massive overexposure over f2.4 or so.

06-13-2012, 06:04 AM   #9
Loyal Site Supporter
eddie1960's Avatar

Join Date: Aug 2010
Location: Toronto
Photos: Gallery | Albums
Posts: 12,270
QuoteOriginally posted by snake Quote
Ok, received the lens and it's really in much better condition than advertised.

I mistakenly posted in the stop-down metering thread about the ring issue-

I can 100% confirm that without the detent ball, the ring does drift during the stopdown metering process. It's worst at f2, when it goes to about f2.4-2.8. Later, there's little movement.

I removed the ring, greased it lightly with a sticky grease, which minimized the drift, though there is still a small amount. The detent ball was there, stuck, and nothing behind it, so it just popped off. I removed it and put it in a safe place, but there was nothing there to hold it in place, oddly.

I'm still trying to figure out how and in what mode to use the lens, as it's not as straight forward as it was on my Olympus e510. Simply, one need only look at the EV meter, adjust, then shoot. Here, I don't seem to have that luxury and I get massive overexposure over f2.4 or so.
how are you metering? massive overexposure seems off, I use manual lenses almost exclusively (either m42 or k and m series) and though there is some exposure issues nothing i would define as massive, and mostly using my m42 lenses in manual where i make a small adjustment using =/- ev

you should be able to spin it to where you want camera in m mode and hit the green button and shoot. metering is limited to spot or center no matrix (i use spot mostly)
06-13-2012, 08:12 AM   #10
Banned




Join Date: Jun 2012
Location: NY/Germany
Posts: 1,183
Original Poster
I would have thought so, too. I have it in center-weighted, but will try spot. I thought it only worked in spot, anyhow.

However, I've tried it again and again and the metering doesn't work right in anything but full or near wide open. Once I get past about f2.8, massive blowing, Like half a dozen stops. I remeter, naturally, using the green button, and the shutter speed drops accordingly, then bam, overexposure.

I know there's a method to this, but I'm not finding it yet and slightly disappointed that using manual lenses is not as easy as with the Olympus+Konica. Mainly, I don't like that the aperture isn't allowed to stay where I put it- meaning the adjustment cam in the body holds it open until the shot is taken or I stop down meter.

Edit: Spot overexposes even more.

I think I'll really have to read much more into this. I think I'm doing it all right, but then I'm getting overexposures. At full open, the exposure is quite good, perhaps 0.3 too high, so it's easy to sett, but below that, it's massively blowing.

Last edited by snake; 06-13-2012 at 08:21 AM.
06-13-2012, 04:31 PM   #11
Banned




Join Date: Jun 2012
Location: NY/Germany
Posts: 1,183
Original Poster
I'm still working through the overexposure issue when stopping down. Odd behavior, to say the least.

Ok, is there any way to get the ev meter displayed full time? I know I can move the power switch all the way over for the aperture actuation/preview and it will display the current light reading in cam, but having this available full-time would really, really make the whole process straight forward for me and is what I'm used to.
Reply

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!
aperture, k-mount, m-series, pentax lens, repair, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pentax-A 50mm f1.7 Aperture ring repair Just1MoreDave Maintenance and Repair Articles 55 05-01-2017 07:54 AM
Auto aperture repair for Cosina Vivitar Series 1 28-105 pdxbales Pentax SLR Lens Discussion 5 01-24-2012 02:43 PM
Repair in Toronto/Canada/US for stuck focus ring DroolingCrow Pentax SLR Lens Discussion 6 08-21-2010 02:05 PM
Use of Aperture-Ring 43mm/1.9 -> no aperture data Deimo Pentax SLR Lens Discussion 7 06-24-2009 03:25 PM



All times are GMT -7. The time now is 03:36 AM. | 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