[pcarfan]

What is the best way to do flash photography with M42 lenses on my K10D and the Pentax AF-540 flash. Thanks.

[Lowell Goudge]

What is the best way to do flash photography with M42 lenses on my K10D and the Pentax AF-540 flash. Thanks.

use "Auto" mode and set the f stop and ISO to match the camera/lens settings.

the flash has its own sensor to measure light in this mode.]

or get yourself an *istD with TTL flash

I have both options

[pcarfan]

use "Auto" mode and set the f stop and ISO to match the camera/lens settings.

the flash has its own sensor to measure light in this mode.]

or get yourself an *istD with TTL flash

I have both options

Thank you


I tried the auto settings but objects close by are way over exposed. I guess it only works with distant object, I guess that's what the distance scale on flashes are for (just realized it as I was typing...I am a P-TTL user and happy with it).

I only have one m42 lens, and really don'ty want to get a camera for it (although I've been considering the *istD for high iso shots).

Is there any ways of getting macro (not true macro requiring ring flashes, but close-up shots) with M42 lenses with my K10D

[Lowell Goudge]

Thank you


I tried the auto settings but objects close by are way over exposed. I guess it only works with distant object, I guess that's what the distance scale on flashes are for (just realized it as I was typing...I am a P-TTL user and happy with it).

don;t worry we all do dumb things from time to time

I only have one m42 lens, and really don'ty want to get a camera for it (although I've been considering the *istD for high iso shots).

yes but the TTL flash also works on K mount lenses, and this is a big reason to get an *istD

Is there any ways of getting macro (not true macro requiring ring flashes, but close-up shots) with M42 lenses with my K10D

if you only have that flash and you want to do macro, the real issue is the min power setting is just too high. why not put a coffee filter over the flash head (don't cover the sensor though) and this should diffuse the flash, less harsh is also better for macro, and cut intensity down.

You could also (if you have a remote trigger wire) move the flash back, and let the light dispurse a little. light intensity falls off at roughly the square of the distance

[pcarfan]

Thank you very much, I appreciate it....

[dlacouture]

Actually, there is a mean to use P-TTL with m42 lenses...
You simply have to short all the pins from the mount, including the A pin (and it's not easy, as it's slightly recessed), and voilà! The k10 will be tricked into thinking it has a f/1.2 PKA lens on.

You'll just have to be sure that you choose f/1.2 on the body (no matter what is the actual aperture on the lens), or you'll end with overexposed shots.

Better yet, this will unlock Matrix metering for m42 (didn't saw any change using it, though)...

This trick won't work with PK-M lenses, by the way, except on some very rare exceptions.

[pcarfan]

Actually, there is a mean to use P-TTL with m42 lenses...
You simply have to short all the pins from the mount, including the A pin (and it's not easy, as it's slightly recessed), and voilà! The k10 will be tricked into thinking it has a f/1.2 PKA lens on.

You'll just have to be sure that you choose f/1.2 on the body (no matter what is the actual aperture on the lens), or you'll end with overexposed shots.

Better yet, this will unlock Matrix metering for m42 (didn't saw any change using it, though)...

This trick won't work with PK-M lenses, by the way, except on some very rare exceptions.

How do I 'short' the pins, and which one is the A pin ?, and if recessed how do I modify the shoring procedure to short that pin as well...thanks.

[dlacouture]

If your lens has a metallic mount, the contacts are already shorted, except for the A contact.
Just for a try, you can use an aluminium foil lodged between the lens and the mount, over the pins location...
It's easier still if your m42 lens is narrow and you can still see the mount's pins once on the camera. This way, wedge the aluminium foil as mentionned above, and press it in the recessed A pin.

[Lowell Goudge]

if you are using the AF TC, it has the ability to focus past infinity, therefore a flanged mount on the lens side could be all that is required.

[egordon99]

The "Auto" setting on the flash should work but if it isn't, try manual mode on the flash. Try it at 1/128 (or whatever the minimum power is). If it still overexposes, either (1)Use a lower ISO, and/or (2)User a smaller aperture (bigger f-number)....If you are still overexposing at ISO100, f/32, and minimum flash power, well.....not sure what to say at that point

[Stratman]

I have used my flash on "auto" mode with M42 lenses, and it works fine, but you have to make sure you pay attention to your settings for shutter speed and aperture. Start out at F5.6 and shutter speed of 180. Then adjust from there, should get you in the ballpark ! And also make sure the ISO settings match on your camera and flash...I almost always use ISO 100 when using flash, so try starting there too.

[pcarfan]

Well I was experimenting with shorting the attachement to use with the Pentax 1.7 AFA adapter, it looks like not only will it autofocus, but the flash is working in P-TTL, can this be ?....I took some trial shots and the exposure was spot on for distant objects, close-by need negative flash compensation and stopping down. The IQ stopped down with the 1.7 afa is great...I think I am going to like this.

P.S: The Pentax 1.7 AFA has six pins, if the last pin (which is usually the 7th pin on the camera and is the data pin), is NOT shorted then I am getting Perefect P-TTL with M42 lenses, and metering and SR.

[Lowell Goudge]

Well I was experimenting with shorting the attachement to use with the Pentax 1.7 AFA adapter, it looks like not only will it autofocus, but the flash is working in P-TTL, can this be ?

perhaps. by shorting the 3rd pin, which is the A mode pin, it will now make the camera think it has an A lens conencted,

....I took some trial shots and the exposure was spot on for distant objects, close-by need negative flash compensation and stopping down. The IQ stopped down with the 1.7 afa is great...I think I am going to like this.

P.S: The Pentax 1.7 AFA has six pins, if the last pin (which is usually the 7th pin on the camera and is the data pin), is NOT shorted then I am getting Perefect P-TTL with M42 lenses, and metering and SR.

No this last point is incorrect, while there are 6 pins on the face the lens mounts to, there are 7 on the body side. the reason is that the AFA must feed focus data for it's elements into the camera body. The last contact on the lens mount side is still part of the apature contacts.

Leaving the data pin unconnected will with a MF lens cause you to loose the focus confirmation.

note also you will only get perfect P-TTL if the apature set on the body is F1.2 otherwise teh body setting will upset the calculation from the preflash reading.

[Ira]

If it's not ttl flash metering, and for close-up work, your flash sensor isn't seeing what your lens is seeing.

The flash might be outputting for the chair 10 feet behind the flower you want to shoot.

If your equipment allows, and especially with digital, go totally manual with the flash and camera and play around.

[newarts]

As Lowell says, short both the A and data pins:


The A pin isn't easy to short because it is recessed. I've done it more or less permanently by jamming some tinfoil into the camera side A pin's recess (it doesn't seem to matter if the camera thinks all my strictly manual lenses are A lenses....but I've not tried to use a K lens.)

Use the e-wheel to turn the aperture down as far as it'll go (probably F 1.2); if F - - appears in the viewfinder, the pins are not shorted (at least for the K100D.)

Now a manually stopped down m42 lens will meter correctly & the on-board flash will be automatically adjusted (at least for a K100D...I'm not sure the data pin must be shorted for all models & would appreciate info on that.)

Iowa Dave

PS at the present time, I've rigged things so my camera thinks all lenses are A type.; this seems to work ok.