Several questions: Wireless / SR / SDM / "exchangeable"

ChooseAName · 09-08-2012, 03:18 PM

What is the reason that there is no wireless flash mode with M lenses? I noticed that when I access the flash menu, the wireless flash option is greyed out. I read in another thread that it has to be at least an A lens.

On a similar note: sometimes if the lighting is such that the camera can get proper exposure without flash, is there a way to always make the pop-up controller flash always go off? (so that the off-camera wireless flash will fire)

Is shake reduction active only when not using flash?

Do SDM lenses have screw drive to "fall back" on?

What does it mean in the Pentax camera pages when it says that certain cameras have or don't have "exchangeable screens"? I'm assuming that this does NOT refer to focusing screens, because all(?) (recent?) Pentax DSLRs have interchangeable focusing screens.

Thanks everyone.

elliott · 09-08-2012, 03:23 PM

Originally posted by ChooseAName

What is the reason that there is no wireless flash mode with M lenses? I noticed that when I access the flash menu, the wireless flash option is greyed out. I read in another thread that it has to be at least an A lens.

The P-TTL mode for automatic flash exposure requires the A contacts, so it knows what the maximum aperture of the lens is. Otherwise it fires the flash at full power every time.

If you want to use flash properly with M lenses, get a good external flash with manual mode. I like using the Yongnuo YN-560, for wireless use get some RF triggers.

Originally posted by ChooseAName

What does it mean in the Pentax camera pages when it says that certain cameras have or don't have "exchangeable screens"? I'm assuming that this does NOT refer to focusing screens, because all(?) (recent?) Pentax DSLRs have interchangeable focusing screens.

Focusing screens can be changed on the lower end bodies, but it is not officially supported and Pentax does not sell screens for these bodies.

Anvh · 09-08-2012, 03:38 PM

For the flash to always go off simply pop it up and it will fire but it fires in P-TTL mode so thats where the problem starts.

shake reduction is always active when set on except with 2 second delay, IR remote and with bulb mode.

SDM lenses come in two flavors, KAF2 and KAF3 mount, KAF2 has SDM and screw-mount, KAF3 only SDM so no screw-mount.
All the DC lenses are KAF3 also all SDM lenses that will come out will be KAF3.

**Just1MoreDave** · 09-08-2012, 05:55 PM

Originally posted by ChooseAName

Do SDM lenses have screw drive to "fall back" on?

Originally posted by Anvh

SDM lenses come in two flavors, KAF2 and KAF3 mount, KAF2 has SDM and screw-mount, KAF3 only SDM so no screw-mount.
All the DC lenses are KAF3 also all SDM lenses that will come out will be KAF3.

That's all correct, but it's important to know: The lenses that have both screw drive and SDM can only use SDM on SDM-enabled bodies. That's the K100D Super, K10D with latest firmware, and everything newer. With old firmware the K10D uses only screwdrive. Pentax has for whatever reason decided you only get one type of focus drive at a time.

Anvh · 09-09-2012, 01:58 AM

Originally posted by Just1MoreDave

Pentax has for whatever reason decided you only get one type of focus drive at a time.

If they both drive at the same time i doubt the lens would like that and the focus motors.

noblepa · 09-09-2012, 10:04 PM

Originally posted by Anvh

If they both drive at the same time i doubt the lens would like that and the focus motors.

I think that what just1moredave was trying to say was that, if your camera is SDM capable and it detects an SDM lens, it will NOT allow the screw drive motor to be used. In other words, the short answer to the OP's question is "no". Pentax does not allow fallback to screw drive.

If I put one of the lenses with both screw drive and SDM on my K10D (firmware 1.31) and the SDM motor fails, my only choice is manual focus. There is no way to force the camera to use screw drive AF when it detects an SDM-capable lens.

If I mount that same failed-SDM lens on a K100D or an *istDS, for exemple, it will function perfectly, since those cameras are not SDM-capable.

As far as I know, all Pentax SDM-capable cameras are this way. Many people have suggested that Pentax could release a simple firmware change to make SDM use optional, but they have not done so.

Anvh · 09-09-2012, 11:09 PM

Originally posted by noblepa

If I mount that same failed-SDM lens on a K100D or an *istDS, for exemple, it will function perfectly, since those cameras are not SDM-capable.

Be careful there, you don't know what has failed on many cases it wasn't the SDM that cause the defect but a misalignment in the AF system itself so if you then start to use the screw-drive who knows what else might break.

09-08-2012, 03:18 PM	#1
ChooseAName Veteran Member Join Date: Aug 2009 Location: Southeast USA Photos: Gallery \| Albums Posts: 390	Several questions: Wireless / SR / SDM / "exchangeable" What is the reason that there is no wireless flash mode with M lenses? I noticed that when I access the flash menu, the wireless flash option is greyed out. I read in another thread that it has to be at least an A lens. On a similar note: sometimes if the lighting is such that the camera can get proper exposure without flash, is there a way to always make the pop-up controller flash always go off? (so that the off-camera wireless flash will fire) Is shake reduction active only when not using flash? Do SDM lenses have screw drive to "fall back" on? What does it mean in the Pentax camera pages when it says that certain cameras have or don't have "exchangeable screens"? I'm assuming that this does NOT refer to focusing screens, because all(?) (recent?) Pentax DSLRs have interchangeable focusing screens. Thanks everyone.

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09-08-2012, 03:23 PM	#2
elliott Inactive Account Join Date: Dec 2008 Location: North Carolina Photos: Albums Posts: 1,720	Originally posted by ChooseAName What is the reason that there is no wireless flash mode with M lenses? I noticed that when I access the flash menu, the wireless flash option is greyed out. I read in another thread that it has to be at least an A lens. The P-TTL mode for automatic flash exposure requires the A contacts, so it knows what the maximum aperture of the lens is. Otherwise it fires the flash at full power every time. If you want to use flash properly with M lenses, get a good external flash with manual mode. I like using the Yongnuo YN-560, for wireless use get some RF triggers. Originally posted by ChooseAName What does it mean in the Pentax camera pages when it says that certain cameras have or don't have "exchangeable screens"? I'm assuming that this does NOT refer to focusing screens, because all(?) (recent?) Pentax DSLRs have interchangeable focusing screens. Focusing screens can be changed on the lower end bodies, but it is not officially supported and Pentax does not sell screens for these bodies.

09-08-2012, 03:38 PM	#3
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	For the flash to always go off simply pop it up and it will fire but it fires in P-TTL mode so thats where the problem starts. shake reduction is always active when set on except with 2 second delay, IR remote and with bulb mode. SDM lenses come in two flavors, KAF2 and KAF3 mount, KAF2 has SDM and screw-mount, KAF3 only SDM so no screw-mount. All the DC lenses are KAF3 also all SDM lenses that will come out will be KAF3.

09-08-2012, 05:55 PM	#4
Just1MoreDave Site Supporter Join Date: Feb 2007 Location: Aurora, CO Photos: Gallery \| Albums Posts: 6,340	Originally posted by ChooseAName Do SDM lenses have screw drive to "fall back" on? Originally posted by Anvh SDM lenses come in two flavors, KAF2 and KAF3 mount, KAF2 has SDM and screw-mount, KAF3 only SDM so no screw-mount. All the DC lenses are KAF3 also all SDM lenses that will come out will be KAF3. That's all correct, but it's important to know: The lenses that have both screw drive and SDM can only use SDM on SDM-enabled bodies. That's the K100D Super, K10D with latest firmware, and everything newer. With old firmware the K10D uses only screwdrive. Pentax has for whatever reason decided you only get one type of focus drive at a time.

09-09-2012, 01:58 AM	#5
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	Originally posted by Just1MoreDave Pentax has for whatever reason decided you only get one type of focus drive at a time. If they both drive at the same time i doubt the lens would like that and the focus motors.

09-09-2012, 10:04 PM	#6
noblepa Veteran Member Join Date: Sep 2007 Location: Bay Village, Ohio USA Posts: 1,142	Originally posted by Anvh If they both drive at the same time i doubt the lens would like that and the focus motors. I think that what just1moredave was trying to say was that, if your camera is SDM capable and it detects an SDM lens, it will NOT allow the screw drive motor to be used. In other words, the short answer to the OP's question is "no". Pentax does not allow fallback to screw drive. If I put one of the lenses with both screw drive and SDM on my K10D (firmware 1.31) and the SDM motor fails, my only choice is manual focus. There is no way to force the camera to use screw drive AF when it detects an SDM-capable lens. If I mount that same failed-SDM lens on a K100D or an *istDS, for exemple, it will function perfectly, since those cameras are not SDM-capable. As far as I know, all Pentax SDM-capable cameras are this way. Many people have suggested that Pentax could release a simple firmware change to make SDM use optional, but they have not done so.

09-09-2012, 11:09 PM	#7
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	Originally posted by noblepa If I mount that same failed-SDM lens on a K100D or an *istDS, for exemple, it will function perfectly, since those cameras are not SDM-capable. Be careful there, you don't know what has failed on many cases it wasn't the SDM that cause the defect but a misalignment in the AF system itself so if you then start to use the screw-drive who knows what else might break.