Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
03-24-2011, 08:44 AM   #1
Pentaxian




Join Date: Jan 2011
Location: New York
Posts: 3,315
Confirm my understand of metering w/ manual lenses focus hyperfocal focus

I am trying to select a manual lens for hyperfocal from-the-hip usage on my K-r. I'll be in and out of shade from buildings and do not want to press the green button before every photo. Basically, I want to set the focus and aperture once, then have the camera constantly adjust the shutter speed as needed.

(FYI 24mm appears to be my ideal length. It's the best compromise between field of view and DOF. The more commonly available 21mm and 28mm aren't as good for me.)

I've checked many posts and articles (such as the 2 below) and want to make sure I understand.
https://www.pentaxforums.com/forums/pentax-beginners-corner-q/110658-using-ma...x-dslrs-f.html
Shooting manual lenses on Pentax DSLRs robertsdonovan.com

1) A Series and newer lenses work fine in Av mode. Manually set aperture using the e-dial (to around f11 for a deep DOF) and the camera will adjust shutter speed as needed. Correct?

2) M42 lenses can also be used in Av mode. Set the aperture on the lens (enable aperture ring in custom settings). The camera will show "F--" but should still continue to meter for shutter speed. The viewfinder will be dark but that's not a concern for hyperfocal usage. Correct?

3) M and K lenses need the green button and/or M mode. Av mode won't meter correctly. Correct?

4) I haven't found much about Adaptall-2. PKA adapters let Av mode work but seem to cost more than the lens. Can I get away with a cheap PK mount and use the aperture ring, or would that require a green button to reset shutter speed every time light conditions change?


03-24-2011, 09:04 AM   #2
Veteran Member
jolepp's Avatar

Join Date: Oct 2010
Location: Finland
Photos: Albums
Posts: 3,196
A-series should meter the same as more modern ones.

M42 lenses are supposed to work in Av, plenty of reports of the reality of that being less than rosy though. As you are going to stick to a more or less fixed aperture, exposure compensation should do it.

M/K will not stop down for exposure in Av.

The El-Cheapo adaptall adapter without the aperture lever would seem to result in the lenses to being equivalent to M42s. BTW ... I seem to recall seeing genuine adaptall-P/K adapters going for much cheaper on ebay.co.uk.
03-24-2011, 03:42 PM   #3
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,400
John

Your summary is pretty close

M42 lenses will work in Av mode but you may need exposure compensation depending upon lens, camera and aperture set. Once compensation is set you will be good to go

K& M lenses need green button to meter correctly in manual mode and do meter in Av mode but only wide open. Additionally these lenses may have metering errors again as a function of lens camera and aperture. Some cameras Do Not allow for ev comp in manual(k10 for certain)

A lenses work in either manual or Av mode and meter much better than M42 or K/M lenses
03-25-2011, 11:43 AM   #4
Junior Member
MobiusOne's Avatar

Join Date: Jul 2010
Photos: Albums
Posts: 46
On Av mode, my M42 lens meters very erratically--shutter speed bounces high and low seemingly randomly or it will need strong positive compensation one shot then negative compensation under the same light. I read that you need to use aluminum tape or sand off some paint at the base of M42 lenses to make sure they contact the pins on the body. Is this true or does this apply to another situation?

03-25-2011, 12:31 PM   #5
Veteran Member
jolepp's Avatar

Join Date: Oct 2010
Location: Finland
Photos: Albums
Posts: 3,196
Making the base conductive has been mentioned in connection with making "catch-in-focus" work with M42 lenses - I wouldn't be terribly surprised if metering was affected as well; it makes no sense as such to treat them differently but then nor does disabling CIF. Also, AWB results would seem to differ in tungsten light with the aperture ring of an A lens in / not in 'A' position (being mistaken for a M lens, probably) with no apparent rationale.
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, av, button, camera, focus, k-mount, lens, lenses, mode, pentax lens, shutter, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
10 Reasons why manual focus primes are better than those new auto focus zoom lenses JoepLX3 Pentax SLR Lens Discussion 188 07-25-2012 03:28 PM
Trying to understand front focus/back focus thing 41ants Troubleshooting and Beginner Help 16 08-31-2010 08:42 AM
Does the K-X have manual focus confirm with ...... dude163 Pentax SLR Lens Discussion 13 05-22-2010 02:46 PM
Manual focus retouching and Hyperfocal Dustin Photographic Technique 13 03-20-2008 06:57 PM



All times are GMT -7. The time now is 12:33 PM. | 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