Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
11-12-2010, 04:31 PM   #16
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
See, I could care less about having to use the green button. What sucks is not being able to focus at the widest aperature so the screen is as bright as possible making focus easier. If you open up to focus, then manually stop down. By that time you lost

11-12-2010, 04:35 PM   #17
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
the point of focus you just caught. So for low light, a true A type meaning open aperture metering is the only way to get perfect focus. A pre-set is a better compromise but still not as good as a true A. Unless you're telling me there's a way to convert M
11-12-2010, 04:36 PM   #18
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
and K lenses to open aperture? If so, woo hoo!
11-12-2010, 04:45 PM   #19
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,314
QuoteOriginally posted by troglodyte Quote
How can you make M and K into an A lens?They still won't do open aperture.They'll keep the same they're dialed at.Unlike an A len like my A 50mm f1.7.Even at f22 which would look pitch black stopped down, it it only do that once I fully depress the shutter
The idea is that if the aperture pins are set up and you shoot with the lens set to minimum aperture the camera body would control the aperture, BUT unfortunately the linearity of the lever action screws it up badly

11-12-2010, 04:55 PM   #20
Veteran Member
paperbag846's Avatar

Join Date: Jul 2010
Photos: Gallery
Posts: 2,396
We are pretty lucky we get to use these old gems at all. Now I wish Pentax would become less popular so they become easy to find .
11-12-2010, 05:00 PM   #21
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
Lowell,
Oh?
My understanding was if a lens isn't an A type like an m42 it will work in Av mode, BUT you have to control the aperture ring manually and it won't stay wide open to focus unlike real A lenses which only stop down for focus preview and to take
11-12-2010, 05:06 PM   #22
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
actual picture. With my A lens if I use the aperture ring in the non-A position I must go to the M dial and use the green button. Otherwise the lens shoots always at f1.7, no matter what the ring says.
11-12-2010, 05:08 PM   #23
Pentaxian




Join Date: Feb 2009
Location: Alameda, CA
Posts: 3,194
QuoteOriginally posted by troglodyte Quote
My understanding was if a lens isn't an A type like an m42 it will work in Av mode, BUT you have to control the aperture ring manually and it won't stay wide open to focus unlike real A lenses which only stop down for focus preview and to take
This thread is about converting pK (NOT m42) mount to pK-A mount.

When you attach a pK lens to a Pentax DSLR body, the aperture is wide open, no matter what its aperture ring is set at. The body does not close down the aperture unless in M mode (and you allow M-lens in the camera setup).

Please do not bring up m42 lenses. That just confuses the issue.

11-12-2010, 05:09 PM   #24
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,314
QuoteOriginally posted by troglodyte Quote
Lowell,
Oh?
My understanding was if a lens isn't an A type like an m42 it will work in Av mode, BUT you have to control the aperture ring manually and it won't stay wide open to focus unlike real A lenses which only stop down for focus preview and to take
M42 lenses yes but k mount lenses will be wide open all the time except in manual mode
11-12-2010, 05:14 PM   #25
Senior Member




Join Date: Nov 2009
Location: Southwest
Photos: Albums
Posts: 155
QuoteOriginally posted by Lowell Goudge Quote
M42 lenses yes but k mount lenses will be wide open all the time except in manual mode
....and wide open for focus even in manual mode. (just to add)
11-12-2010, 05:15 PM   #26
Veteran Member




Join Date: Nov 2010
Location: Huntsville, Alabama
Posts: 422
Original Poster
QuoteOriginally posted by troglodyte Quote
How can you make M and K into an A lens?They still won't do open aperture.They'll keep the same they're dialed at.Unlike an A len like my A 50mm f1.7.Even at f22 which would look pitch black stopped down, it it only do that once I fully depress the shutter
You set the lens to the highest number f stop.

It uses the camera metering to determine what it needs to be stopped down to. Then it stops it down to that value when you press the shutter.
11-12-2010, 05:21 PM   #27
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
Lowell,
Hmmm.
So let me get this straight. With K and M lenses. Say it's an f2. I set the ring to f8. When I'm in Av the lens will focus as f2. When I click the shutter the camera will close the iris to f8 I set the ring to? So the only 'problem' is I need
11-12-2010, 05:24 PM   #28
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
to set the aperture on the lens ring and not on the camera dial? Is that what people are complaing about? If so it sounds better than my A. I hate setting aperture by dial and wish I could use the ring in Av
11-12-2010, 05:49 PM   #29
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
Cyclone & lowspark,Your posts seem to indicate that's the case.If so,I don't see why people pick On M and K lenses so much. Also, I was thinking of once getting the K version of the Helios 44 and read everyone say not to and get the m42. Since the K vesion
11-12-2010, 05:51 PM   #30
Veteran Member




Join Date: Jul 2010
Location: Oz
Posts: 412
won't meter in Av mode and must use the M mode with the green button while the m42 while having manual aperture ring could use the Av? So what gives?
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!
k-mount, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
How to make a non-A lens work like an A-lens Egg Salad Do-It-Yourself 6 06-06-2010 04:18 AM
Wanted - Acquired: Cheap "donor" KA-mount 28mm f/2.8 lens - any make panoguy Sold Items 2 03-04-2010 08:02 PM
Is there something that can make my lens into a zoom lens? CrossStealth Troubleshooting and Beginner Help 15 02-14-2010 01:26 PM
Is DXO lens correction really able to make a lens THAT much better? shaolin95 Digital Processing, Software, and Printing 10 09-22-2009 07:53 PM
Why doesn't Pentax make a camera that uses another manufactures lens mount? steffi Pentax DSLR Discussion 44 04-18-2007 08:14 AM



All times are GMT -7. The time now is 04:04 PM. | 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