Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-09-2008, 02:50 PM   #31
Moderator
Site Supporter
Blue's Avatar

Join Date: Jun 2008
Location: Florida Hill Country
Photos: Gallery | Albums
Posts: 17,166
QuoteOriginally posted by Mike.P Quote
As far as I am aware there are no extension tubes that are capable of autofocus (no doubt someone will now prove me wrong) but they are compatible with the "A" setting so will be a lot more useful than the ones without.
I actually only want the tubes, it was worth the price for them alone .. the F 1.7 is just a bonus
Kenko made some in the past that were AF compatible, but they are out of production and very hard to find used.

Edit: surprisingly, there is one listed in the marketplace: https://www.pentaxforums.com/forums/photographers-marketplace/41255-kenko-uni...brand-new.html

12-09-2008, 02:50 PM   #32
Site Supporter
ChrisPlatt's Avatar

Join Date: Nov 2007
Location: Queens NYC
Posts: 4,433
QuoteOriginally posted by Blue Quote
The Spot F requires an adapter to use silver batteries or a Wein cell because the Silver batteries provide too high of a voltage.
Not true. The Spotmatic F meter has a bridge circuit and is relatively immune to voltage variations.

Though originally equipped with the now-banned 1.3V mercury 625 battery,
the Spotmatic-F will work perfectly with the modern 1.5V silver (or alkaline) 625 replacement.

Chris
12-09-2008, 03:06 PM   #33
Moderator
Site Supporter
Blue's Avatar

Join Date: Jun 2008
Location: Florida Hill Country
Photos: Gallery | Albums
Posts: 17,166
QuoteOriginally posted by ChrisPlatt Quote
Not true. The Spotmatic F meter has a bridge circuit and is relatively immune to voltage variations.

Though originally equipped with the now-banned 1.3V mercury 625 battery,
the Spotmatic-F will work perfectly with the modern 1.5V silver (or alkaline) 625 replacement.

Chris
Are you sure the F doesn't have a dual coil meter? The F had a revised meter design to take advantage of the "new" open-aperture metering, using the updated Super-Multi-Coated (S-M-C) Takumar lenses. The meter had higher power demands as a result. The ES was further revised to take a silver oxide battery and the ES II took 4.

Edit: I guess this is a question for Eric.

Last edited by Blue; 12-09-2008 at 03:15 PM.
12-09-2008, 03:48 PM   #34
Pentaxian
jsherman999's Avatar

Join Date: Dec 2007
Photos: Gallery
Posts: 8,228
QuoteOriginally posted by Blue Quote
Are you sure the F doesn't have a dual coil meter? The F had a revised meter design to take advantage of the "new" open-aperture metering, using the updated Super-Multi-Coated (S-M-C) Takumar lenses. The meter had higher power demands as a result. The ES was further revised to take a silver oxide battery and the ES II took 4.

Edit: I guess this is a question for Eric.

Why don't we consult The Manual:






12-09-2008, 04:11 PM   #35
Pentaxian
Mike.P's Avatar

Join Date: Mar 2008
Location: South Coast .. UK
Photos: Gallery
Posts: 1,734
QuoteOriginally posted by Blue Quote
Kenko made some in the past that were AF compatible, but they are out of production and very hard to find used.

See, I said someone would prove me wrong
I'm not sure how useful AF would be with tubes, I only use manual focus with macro lenses as AF is virtually useless that close so with tubes I would have thought it would be even more difficult to get a decent lock.

Cheers for the info though.
12-09-2008, 04:45 PM   #36
Site Supporter
ChrisPlatt's Avatar

Join Date: Nov 2007
Location: Queens NYC
Posts: 4,433
QuoteOriginally posted by Blue Quote
Are you sure the F doesn't have a dual coil meter? The F had a revised meter design to take advantage of the "new" open-aperture metering, using the updated Super-Multi-Coated (S-M-C) Takumar lenses. The meter had higher power demands as a result. The ES was further revised to take a silver oxide battery and the ES II took 4.
The ES and ESII have greater power requirements, mainly for their electronic shutters.
The SP-F has a mechanical shutter.

No additional electrical power is required for full-aperture metering with SMC Takumar lenses.
An additional mechanical coupling is used to transmit set aperture to the camera's meter.

The SP-F meter turns on automatically whenever lens cap is removed.
Of course if left off for long periods battery will run down...

Chris
12-09-2008, 05:08 PM   #37
Moderator
Site Supporter
Blue's Avatar

Join Date: Jun 2008
Location: Florida Hill Country
Photos: Gallery | Albums
Posts: 17,166
Wow. The manual calls it a 1.5 volt mercury battery when in fact it is a 1.35 volt battery. I don't see anything in the manual about the F having a bridge circuit or dual coil circuit, but it implies that the metering system is more like that of the ES and ES II than previous Spotmatics. I've been using zinc air batteries in my F to be on the safe side and a little more accuracy if nothing else.
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, lba, lenses, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
People Little Miss P Falcons Post Your Photos! 3 12-21-2009 01:00 PM
Why do I ALWAYS miss? KierraElizabeth Troubleshooting and Beginner Help 24 11-11-2009 12:30 AM
I miss her already! Canada_Rockies Photographic Technique 1 07-14-2009 02:10 AM
I sure miss my DA 16-45 f/4 Ed in GA Pentax SLR Lens Discussion 25 01-11-2008 01:11 PM
What I miss (and don't miss) about my K10D switters Pentax DSLR Discussion 35 01-06-2008 02:51 AM



All times are GMT -7. The time now is 12:04 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