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View Full Version : K100D compatibility with old TTL flash units



mathetes
10-03-2006, 08:14 AM
I just acquired a K100D yesterday, after first determining that the "limited functionality" their lens chart talks about for all of my old lenses (for the LX generation of film cameras) really meant "full functionality" for all that the lenses were ever designed to do; suprisingly, manual focus lenses don't become auto-focus; that's why they call it "limited..." :cool:

Anyway, I thought I'd see if my old AF280 T flash unit would work as well, since it offered TTL management of the light level. And at least a few experiments last night, with the new auto-everything lens that came with the camera, seemed to suggest that it works just fine. It did NOT work with the older lenses, however -- total washout of the picture. I still want to experiment with setting the ISO speed of the CCD at a fixed point and setting the flash to the same, to see if the two can work together.

My question for this community: has anybody else has tried the same -- using the older hot-shoe mounted flash units, capable of TTL metering, on the K100D or other comparable Pentax DSLRs ... what are your experiences are if so?

Thanks

Colin T
10-03-2006, 10:36 AM
Hi mathetes

I haven't yet tried my old flash on the K100D but I have tried using an old lens with the flash that is on the camera. The results are rather poor. The aperture needs to be right open (F4) otherwise you end up with dark pictures. And the flash only seems to have a range of about 4-6 feet with the old lens which is a far cry from what the book states (2.5ft-14ft).

mathetes
10-03-2006, 02:59 PM
Hi mathetes

... I have tried using an old lens with the flash that is on the camera. The results are rather poor. The aperture needs to be right open (F4) otherwise you end up with dark pictures. And the flash only seems to have a range of about 4-6 feet with the old lens which is a far cry from what the book states (2.5ft-14ft).

Colin -- I just tried the built-in flash with my 100 mm Takumar lens, with good results over 20 feet or so, and at small apertures as well. Now, I have the camera set to Av mode (aperture priority) and I have set the custom menu option that allows "using aperture ring," which is what you need to do to use a lens such as I have that doesn't have an "A" setting. My lens is an old fully manual macro (and moderate telephoto) lens, but those settings seem to be what enables the K100D to work with it.

Still haven't done the other experimenting ... but this was satisfactory ...

rjromero10
10-04-2006, 10:58 AM
Hi Mathetes,
from what I have read the K100 is not TTL compatible. It will use the flash at full power all the time, I think. I am not 100% sure. As for your manual lens w/Flash. Set the camera to M (manual mode), the apeture between F5.6 - F8 and shutter between 1/80 - 1/160. If you use the Av mode the lens will always be wide open apeture.
Use the lens in M and use the AE-L button to meter for you depending upon the apeture you select. This does not work with flash, the cameras seem to ignore the fact that you have a flash and meter as if you don't. Again with flash try the manual settings above.

Spot focus
10-31-2006, 01:52 AM
This might help;)
http://www.popphoto.com/photonews/2729/sigma-issues-notice-to-pentax-customers.html

mathetes
11-02-2006, 10:49 PM
I have experimented a bit more, and can report that the old external flash will operate just fine if I put it into manual mode for ISO 200 (where the camera is set as well) and then put the K100D into manual mode and set the aperture to the setting recommended for either the red or the green manual mode ... with the automatic lens. I still need to experiment more with the older lenses, should I want to use them.

But for the most part, the new automatic lens, with its 18-55 mm zoom range, is perfect anyway. And the old external Pentax flash gives me the ability to use it in "bounce" mode, for much more softly lit scenes than the built-in flash can manage.

:D