Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-23-2009, 04:54 AM   #1
Veteran Member
LeDave's Avatar

Join Date: Jun 2009
Location: Minneapolis - St. Paul
Photos: Gallery
Posts: 3,061
Permanent quick-shift?

You know how when you flick the switch from MF to AF, the screw-drive pops out, while when you flick the switch from AF to MF, the screw pops in?

Wouldn't it be awesome if Pentax somehow designed the body in a way so that when you press the shutter half-way or the AF button, that the screw would pop out to AF. And when you lay your fingers off of it, the screw would pop in again? This would allow quick-shift in all lenses, especially ones from Sigma and Tamron which doesn't boast such a feature.

EDIT: Ah, epic fail. I don't know what I was thinking when I wrote this, but must be because it's 6am and I haven't slept yet. Obviously you won't be able to quick-shift after you release your fingers off it because it would have to re-AF when you press it again.

Well if there was a way to somehow program another button such as the dedicated AF button to do it. While your camera auto-focuses when your finger is half-way down on the shutter button, you can somehow press the dedicated AF button while still holding the shutter half-way down, thus allowing the screw-drive to pop-in for quick-shifting.


Last edited by LeDave; 12-23-2009 at 05:15 AM.
12-23-2009, 01:31 PM   #2
Veteran Member




Join Date: Aug 2009
Location: NY
Posts: 407
You can just press the lens release button which retracts the screw drive, manual focus then release. You run a slight risk of a lens falling off!. Most are pretty tight on my K20.

Not sure if there are any other drawbacks to using the lens release button. Anyone?
12-23-2009, 01:38 PM   #3
Forum Member




Join Date: Dec 2009
Posts: 72
The best option would be

I think the best option would be an AF system that disengages automatically when not focusing. This would have the disadvantage that you could accidentally change the focus after focusing.
The other option, more sophisticated, would measure the torque on the shaft, and either have a slipping joint or take current away from the screw drive motor.

Lots of possibilities, but they would all add to the cost.
I think the quick shift DA lenses have a torque slip joint. But put it into the camera, and all lenses would immediately be quick shift.

Hmm...

D.
12-23-2009, 02:39 PM   #4
Veteran Member
Andi Lo's Avatar

Join Date: Jul 2008
Location: Halifax, Nova Scotia
Posts: 2,923
QuoteOriginally posted by LeDave Quote
EDIT: Ah, epic fail. I don't know what I was thinking when I wrote this, but must be because it's 6am and I haven't slept yet. Obviously you won't be able to quick-shift after you release your fingers off it because it would have to re-AF when you press it again.
Why not just disengage AF from shutter and trigger AF slot drive in with the AF button? It will be the same as your suggestion, just not requiring the use of another button.

I think the reason why pentax doesnt have this (and also the reason why AF button is mechanical instead of electronic) is because it's harder to push/pull the pin with sufficient force. Nothing impossible to design around when you put your mind into it though.

Of course we can also just have improved SDM. SDM doesnt need a slot be pushed, so the lens can be just always MF unless the current flows through it.

12-23-2009, 10:09 PM   #5
Loyal Site Supporter
Loyal Site Supporter
Canada_Rockies's Avatar

Join Date: Nov 2007
Location: Sparwood, BC, Canada
Photos: Gallery | Albums
Posts: 11,802
QuoteOriginally posted by LeDave Quote
You know how when you flick the switch from MF to AF, the screw-drive pops out, while when you flick the switch from AF to MF, the screw pops in?

Wouldn't it be awesome if Pentax somehow designed the body in a way so that when you press the shutter half-way or the AF button, that the screw would pop out to AF. And when you lay your fingers off of it, the screw would pop in again? This would allow quick-shift in all lenses, especially ones from Sigma and Tamron which doesn't boast such a feature.

EDIT: Ah, epic fail. I don't know what I was thinking when I wrote this, but must be because it's 6am and I haven't slept yet. Obviously you won't be able to quick-shift after you release your fingers off it because it would have to re-AF when you press it again.

Well if there was a way to somehow program another button such as the dedicated AF button to do it. While your camera auto-focuses when your finger is half-way down on the shutter button, you can somehow press the dedicated AF button while still holding the shutter half-way down, thus allowing the screw-drive to pop-in for quick-shifting.
I can set the [AF] button on my Pentax K10D to Cancel AF - would that work for you? I have the following three options for the [AF] button:
  1. Enable AF
  2. Cancel AF
  3. Center of AF point - If you have selected a point other than the center point, this selects the centre point.
12-24-2009, 12:54 AM   #6
Senior Member
sajah's Avatar

Join Date: Mar 2009
Location: South Korea
Photos: Gallery
Posts: 275
I have OK button set to cancel AF too. But this alone is not enough, because even though the AF is cancelled, you still can't turn the focus ring manually, because it's still coupled with the AF screw. Unless the lens has quick-shift, where you can always turn the focus ring in any focusing mode.

I agree with Diffusion here, there's a mechanical mechanism inside DA lens to enable quick-shift, and I think there should be no problem to transfer this mechanism to inside the body instead. But I could (very likely) be wrong though
12-24-2009, 12:05 PM   #7
Veteran Member




Join Date: Jan 2009
Location: Frozen white North
Photos: Albums
Posts: 848
QuoteOriginally posted by Andi Lo Quote
Of course we can also just have improved SDM. SDM doesnt need a slot be pushed, so the lens can be just always MF unless the current flows through it.
Most SDM lenses end up being MF anyways

Ok, ok, there's other threads for that
12-24-2009, 01:09 PM   #8
Veteran Member




Join Date: Mar 2009
Location: Perth Australia
Photos: Albums
Posts: 1,514
QuoteOriginally posted by LeDave Quote
EDIT: Ah, epic fail. I don't know what I was thinking when I wrote this, but must be because it's 6am and I haven't slept yet. Obviously you won't be able to quick-shift after you release your fingers off it because it would have to re-AF when you press it again.
Kx, K7, and K20d can disable the AF on half shutter press and move it to the AF button.

Once I tried this, I couldn't live without it, I (now) hate having the camera focus every time you half press.

Because now your camera just fires when you press the shutter instead of (potentially) dicking around And you can pre focus (for timing), and recompose without holding something down, and shoot panorama's with infinite set once... etc.

In fact the more I think about it any one outside of green mode newbies should have it disabled.

12-27-2009, 02:32 AM   #9
Veteran Member
darrenleow's Avatar

Join Date: Feb 2009
Location: Chicago
Photos: Gallery
Posts: 541
QuoteOriginally posted by LeDave Quote
You know how when you flick the switch from MF to AF, the screw-drive pops out, while when you flick the switch from AF to MF, the screw pops in?

Wouldn't it be awesome if Pentax somehow designed the body in a way so that when you press the shutter half-way or the AF button, that the screw would pop out to AF. And when you lay your fingers off of it, the screw would pop in again? This would allow quick-shift in all lenses, especially ones from Sigma and Tamron which doesn't boast such a feature.

EDIT: Ah, epic fail. I don't know what I was thinking when I wrote this, but must be because it's 6am and I haven't slept yet. Obviously you won't be able to quick-shift after you release your fingers off it because it would have to re-AF when you press it again.

Well if there was a way to somehow program another button such as the dedicated AF button to do it. While your camera auto-focuses when your finger is half-way down on the shutter button, you can somehow press the dedicated AF button while still holding the shutter half-way down, thus allowing the screw-drive to pop-in for quick-shifting.
I tried my friend's KM 7D for a brief period when waiting for my K20D and it had this feature. The AF button toggled the screw connection with the lens.

QuoteOriginally posted by WerTicus Quote
Kx, K7, and K20d can disable the AF on half shutter press and move it to the AF button.

Once I tried this, I couldn't live without it, I (now) hate having the camera focus every time you half press.

Because now your camera just fires when you press the shutter instead of (potentially) dicking around And you can pre focus (for timing), and recompose without holding something down, and shoot panorama's with infinite set once... etc.

In fact the more I think about it any one outside of green mode newbies should have it disabled.
The one thing stopping me from using this method on my K20D is that the AF button is not duplicated on the battery grip and too far away to reach with my thumb when using the grip. Not sure how to work around this, short of buying a K-7 and grip
12-27-2009, 02:35 AM   #10
Veteran Member
LeDave's Avatar

Join Date: Jun 2009
Location: Minneapolis - St. Paul
Photos: Gallery
Posts: 3,061
Original Poster
QuoteOriginally posted by darrenleow Quote
I tried my friend's KM 7D for a brief period when waiting for my K20D and it had this feature. The AF button toggled the screw connection with the lens.
So current Sony DSLR's have this feature too then?
12-27-2009, 02:39 AM   #11
Veteran Member
darrenleow's Avatar

Join Date: Feb 2009
Location: Chicago
Photos: Gallery
Posts: 541
QuoteOriginally posted by LeDave Quote
So current Sony DSLR's have this feature too then?
On the A700:

"Next to that is the AF/MF button, which lets you quickly switch between auto and manual focus -- handy if you need to make a quick adjustment to the focus. "

DCRP Review: Sony Alpha DSLR-A700

I guess so!

Edit: I just happened to read about a "Direct Manual Focus" mode on Sony DSLRs, which automatically disconnects the screwdrive once the AF has locked, freeing the focus ring. Pretty neat.
12-27-2009, 02:53 AM   #12
Veteran Member
LeDave's Avatar

Join Date: Jun 2009
Location: Minneapolis - St. Paul
Photos: Gallery
Posts: 3,061
Original Poster
QuoteOriginally posted by darrenleow Quote
On the A700:

"Next to that is the AF/MF button, which lets you quickly switch between auto and manual focus -- handy if you need to make a quick adjustment to the focus. "

DCRP Review: Sony Alpha DSLR-A700

I guess so!

Edit: I just happened to read about a "Direct Manual Focus" mode on Sony DSLRs, which automatically disconnects the screwdrive once the AF has locked, freeing the focus ring. Pretty neat.
Ah the A700 is such a beautiful camera, being a 7D clone and all. It's a shame current Sony APS-C's aren't built like they used to anymore. I guess it's what happens when a company's greed overtakes the better, deciding they want to save the build quality for their full frames. Just hope the K-x isn't signs that Pentax is doing the same for whatever full frame they're going to announce soon.
12-27-2009, 12:41 PM   #13
Inactive Account




Join Date: Oct 2009
Location: Somewhere in VA
Posts: 104
Memorize the selector switch positions.


Problem solved
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!
af, button, camera, dslr, fingers, photography, pop, press, quick-shift, screw, shutter, switch
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Quick shift: video <--> RAW ? Jaboney Video and Pentax HDSLRs 3 03-10-2010 06:45 PM
Quick Shift, for Canikon? systemA Non-Pentax Cameras: Canon, Nikon, etc. 7 01-27-2010 03:40 PM
Kx DA L quick shift dilemma! Flopass Troubleshooting and Beginner Help 4 11-25-2009 01:06 PM
k-x with quick shift lense? p0opstlnksal0t Pentax DSLR Discussion 2 10-21-2009 04:08 AM
Pentax 1.7 AFA: Can it be used like quick shift? pcarfan Pentax Camera and Field Accessories 0 02-12-2009 05:23 AM



All times are GMT -7. The time now is 11:08 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