Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
3 Likes  #1
M* / A* 300mm disassembly/cleaning guide
Posted By: RXrenesis8, 01-30-2012, 06:44 PM

(Posted as a request) . If anyone can take this a step further and elaborate on the rear elements I'd be grateful!

Also note: I am using made-up names for some of the parts (front element assembly?) Any corrections will be appended to the text of the post.



Step 1: focus the lens at 4 meters (< 14 feet).



Step 2: grip the lens by the aperture ring (or mount, or anything attached to the mount, ie: a camera) and the front protective cover and twist the front protective cover clockwise until it falls down and hangs loosely.



Step 3: grip the focus ring and the front element assembly and twist the front element assembly counter-clockwise until it disengages.



Step 4: remove the lens hood from the front protective cover and set aside.



Step 5: attach the front element assembly securely to the lens by turning it clockwise



Step 6: attach the front protective cover to the front element assembly by pressing it up and turning it counterclockwise.

(I could swear I took a picture of this...)


Step 7: continue turning the front protective cover counterclockwise until the front half of the lens disengages from the back half and set the back half aside.



Step 8: remove the front element assembly from the front protective cover by turning counter clockwise.



Step 9: twist the front element assembly apart by rotating the front element counter clockwise.






In this state of disassembly you can clean most of the lens surfaces and the aperture blades.

I think that's it for the easy stuff. Pretty sure the rest requires unscrewing tiny little screws on the mount but I haven't gone that far yet.

Last edited by RXrenesis8; 02-17-2012 at 10:54 AM.
Views: 6,345
01-30-2012, 07:43 PM   #2
Pentaxian
MegaPower's Avatar

Join Date: May 2010
Location: Hong Kong / Irvine, CA
Photos: Gallery | Albums
Posts: 561
although my A*300 does not need disassembling, bump for you.

stored this for future reference.
01-30-2012, 08:04 PM   #3
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 40,958
Moving this to the articles section. Excellent resource!

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com's high server and development costs are user-supported. You can help cover those costs by donating. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

01-31-2012, 01:58 AM   #4
New Member




Join Date: Mar 2010
Location: Stirlingshire
Posts: 4
I was that request!!

Thanks for taking the time to post such a detailed guide to dissasembly of this lens. The sliding hood on my otherwise perfect copy was quite loose, so I wanted to replace the felt slider inside it. There is no way I would have figured out how it came off, but now I know.

Many thanks for providing such a useful article, and in under 24 hours of my post to you! Guys like you make Pentaxforums the great resource it is!

02-17-2012, 10:54 AM   #5
Veteran Member
RXrenesis8's Avatar

Join Date: Jan 2011
Location: Orlando, FL (USA)
Photos: Gallery | Albums
Posts: 523
Original Poster
Another tip (worked out from helping another forum member disassemble his M* 300): If the elements are stuck: use a big rubber band around them for grip!
02-18-2012, 03:12 AM   #6
New Member




Join Date: Mar 2010
Location: Stirlingshire
Posts: 4
Anyone know what the specification is for the felt like slider materials that are fitted between the inside the hood and the lens body, or where to get them? I want to replace these worn strips on my A*300 to stop the hood sliding under its own weight.

There is a 3/8ths inch wide grey flat strip of material attached to the inside rear end of the hood, and a thinner more rounded black velvet like material around the body near the front of the lens.

I'm in the UK but any ideas or sources of material are of interest.

Thanks for any help or advice!
02-18-2012, 04:41 AM   #7
jac
Loyal Site Supporter




Join Date: Dec 2010
Location: Clyde River, Nunavut, Canada
Posts: 2,363
Ditto Ed. My glass is clean but the hood has a mind of its own. Great article! Thanks.
02-18-2012, 05:43 AM   #8
Veteran Member
RXrenesis8's Avatar

Join Date: Jan 2011
Location: Orlando, FL (USA)
Photos: Gallery | Albums
Posts: 523
Original Poster
I'll email or have a chat with pentax support to see if I can't find out. Mine flops around as well.

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!
a* 300mm, counter, element, front, half, lens, mount, step, twist
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
ZX-5n disassembly with pictures Sluggo Pentax Film SLR Discussion 21 11-17-2011 11:23 AM
Help: K 50mm 1.4 disassembly EddieAmzel Pentax SLR Lens Discussion 5 09-19-2011 10:28 AM
Lens disassembly & cleaning garethwebber Pentax SLR Lens Discussion 3 03-31-2011 12:59 PM
DA 40mm F2.8 Limited Disassembly/cleaning? dcshooter Pentax SLR Lens Discussion 1 02-27-2011 02:44 AM



All times are GMT -7. The time now is 01:52 AM. | See also: NikonForums.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