Questions about using M42 lenses - focus and metering

**Spodeworld** · 09-23-2011, 02:14 PM

It seems like when I put my flash on with a manual lens and Av mode, even if I dial down the flash output, I seem to get the same exposure. I thought dialing down the flash output would impact the exposure, but unless I am doing something wrong, I am not seeing it.

sterretje · 09-23-2011, 10:26 PM

Just with regards to center focus with M42 lenses

page 107 of the manual for the K20D

Quote:

The AF point is fixed to the center position regardless of this setting with lenses other than DA, D FA, FA J, FA or F lenses.

MobiusOne · 09-27-2011, 09:32 AM

Originally posted by Spodeworld

It seems like when I put my flash on with a manual lens and Av mode, even if I dial down the flash output, I seem to get the same exposure. I thought dialing down the flash output would impact the exposure, but unless I am doing something wrong, I am not seeing it.

Flash will always fire at full power, regardless of the flash power setting, when you're using manual lenses like Pentax-M or M42s. You can dial down the flash only if you're using Pentax-A lenses or newer.

Yeah, pisses me off, too.

**Spodeworld** · 10-06-2011, 12:10 PM

Well that explains that mystery. Thanks....that's really too bad indeed!

Originally posted by MobiusOne

Flash will always fire at full power, regardless of the flash power setting, when you're using manual lenses like Pentax-M or M42s. You can dial down the flash only if you're using Pentax-A lenses or newer.

Yeah, pisses me off, too.

Stratman · 10-09-2011, 06:51 PM

Does your flash have an "Auto" setting? Not TTL or P-TTL, but Auto? If so, you can get correct exposures with manual lenses once you learn how the flash works..

**Lowell Goudge** · 10-10-2011, 05:21 PM

Originally posted by Stratman

Does your flash have an "Auto" setting? Not TTL or P-TTL, but Auto? If so, you can get correct exposures with manual lenses once you learn how the flash works..

Although perhaps not what people may not wish to hear if you want to shoot flash with M42 lenses get an *istD

Ful TTL flash including high speed sync with M 42 lenses

**Spodeworld** · 10-12-2011, 06:40 AM

Well, I was discussing the pop up flash. But, I recently picked up an old flash that does have Auto, and that suggestion is a good one. I was trying to work out if I could get more control over the output of the pop up, but it appears that when you have a M42 lens on there, the pop up is full blast regardless of what you set the flash output to.

Originally posted by Stratman

Does your flash have an "Auto" setting? Not TTL or P-TTL, but Auto? If so, you can get correct exposures with manual lenses once you learn how the flash works..

RioRico · 10-12-2011, 08:24 AM

Originally posted by Spodeworld

Well, I was discussing the pop up flash. But, I recently picked up an old flash that does have Auto, and that suggestion is a good one. I was trying to work out if I could get more control over the output of the pop up, but it appears that when you have a M42 lens on there, the pop up is full blast regardless of what you set the flash output to.

Just a reminder that before using an old flash on a modern dSLR, be sure to CHECK THE TRIGGER VOLTAGE! so that the flash doesn't FRY THE CAMERA'S ELECTRONICS!! Of course you've already done that, but anyone new to the old-flash game should be aware of the danger. DON'T BRICK THE CAMERA!

**Spodeworld** · 10-12-2011, 10:01 AM

Yes, you're absolutely right. I picked up a Pentax AF 280T, which I checked out and found out works pretty well with the newer DSLRs and won't fry the camera. Your advice to check out voltage compatibility is very crucial though.

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09-23-2011, 02:14 PM	#16
Spodeworld Site Supporter Join Date: Aug 2011 Location: New Joisey Photos: Gallery \| Albums Posts: 1,370 Original Poster	It seems like when I put my flash on with a manual lens and Av mode, even if I dial down the flash output, I seem to get the same exposure. I thought dialing down the flash output would impact the exposure, but unless I am doing something wrong, I am not seeing it.

09-23-2011, 10:26 PM	#17
sterretje Veteran Member Join Date: Dec 2008 Location: Roodepoort, South Africa Photos: Gallery \| Albums Posts: 3,561	Just with regards to center focus with M42 lenses page 107 of the manual for the K20D Quote: The AF point is fixed to the center position regardless of this setting with lenses other than DA, D FA, FA J, FA or F lenses.

09-27-2011, 09:32 AM	#18
MobiusOne Junior Member Join Date: Jul 2010 Photos: Albums Posts: 46	Originally posted by Spodeworld It seems like when I put my flash on with a manual lens and Av mode, even if I dial down the flash output, I seem to get the same exposure. I thought dialing down the flash output would impact the exposure, but unless I am doing something wrong, I am not seeing it. Flash will always fire at full power, regardless of the flash power setting, when you're using manual lenses like Pentax-M or M42s. You can dial down the flash only if you're using Pentax-A lenses or newer. Yeah, pisses me off, too.

10-06-2011, 12:10 PM	#19
Spodeworld Site Supporter Join Date: Aug 2011 Location: New Joisey Photos: Gallery \| Albums Posts: 1,370 Original Poster	Well that explains that mystery. Thanks....that's really too bad indeed! Originally posted by MobiusOne Flash will always fire at full power, regardless of the flash power setting, when you're using manual lenses like Pentax-M or M42s. You can dial down the flash only if you're using Pentax-A lenses or newer. Yeah, pisses me off, too.

10-09-2011, 06:51 PM	#20
Stratman Veteran Member Join Date: Mar 2007 Location: St Louis, Missouri U S A Photos: Gallery \| Albums Posts: 2,464	Does your flash have an "Auto" setting? Not TTL or P-TTL, but Auto? If so, you can get correct exposures with manual lenses once you learn how the flash works..

10-10-2011, 05:21 PM	#21
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,891	Originally posted by Stratman Does your flash have an "Auto" setting? Not TTL or P-TTL, but Auto? If so, you can get correct exposures with manual lenses once you learn how the flash works.. Although perhaps not what people may not wish to hear if you want to shoot flash with M42 lenses get an *istD Ful TTL flash including high speed sync with M 42 lenses

10-12-2011, 06:40 AM	#22
Spodeworld Site Supporter Join Date: Aug 2011 Location: New Joisey Photos: Gallery \| Albums Posts: 1,370 Original Poster	Well, I was discussing the pop up flash. But, I recently picked up an old flash that does have Auto, and that suggestion is a good one. I was trying to work out if I could get more control over the output of the pop up, but it appears that when you have a M42 lens on there, the pop up is full blast regardless of what you set the flash output to. Originally posted by Stratman Does your flash have an "Auto" setting? Not TTL or P-TTL, but Auto? If so, you can get correct exposures with manual lenses once you learn how the flash works..

10-12-2011, 08:24 AM	#23
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	Originally posted by Spodeworld Well, I was discussing the pop up flash. But, I recently picked up an old flash that does have Auto, and that suggestion is a good one. I was trying to work out if I could get more control over the output of the pop up, but it appears that when you have a M42 lens on there, the pop up is full blast regardless of what you set the flash output to. Just a reminder that before using an old flash on a modern dSLR, be sure to CHECK THE TRIGGER VOLTAGE! so that the flash doesn't FRY THE CAMERA'S ELECTRONICS!! Of course you've already done that, but anyone new to the old-flash game should be aware of the danger. DON'T BRICK THE CAMERA!

10-12-2011, 10:01 AM	#24
Spodeworld Site Supporter Join Date: Aug 2011 Location: New Joisey Photos: Gallery \| Albums Posts: 1,370 Original Poster	Yes, you're absolutely right. I picked up a Pentax AF 280T, which I checked out and found out works pretty well with the newer DSLRs and won't fry the camera. Your advice to check out voltage compatibility is very crucial though.