Jens Bladt wrote:
You are, of course, right, John. What bothers me, is that the camera actually does stop down when fired as described, but aparently to late. I guess it would have been quite simple (small ajustments) to turn the green button into a temporary shutter release, using a custums function and perhaps one small electronic contact. All the best. Jens
Jens Bladt mailto:[EMAIL PROTECTED] http://hjem.get2net.dk/bladt
-----Oprindelig meddelelse----- Fra: John Francis [mailto:[EMAIL PROTECTED] Sendt: 8. september 2004 19:12 Til: [EMAIL PROTECTED] Emne: Re: Amazing Discovery (was: IST D and Pentax-F 1.7x AF adapter)
Jens Bladt mused:
With the AF 1.7x adapter on the *ist D, an A or M lens works in GreenMode,
P-Mode, Tv-Mode and Av-mode (works like aperture priority in all cases) - without using the greene button. I just tried on f2.8, f8 and f22. All 12 images came out correctly exposed!
That's kind of sensational, isn't it!? All the best
Jens Bladt
It's more than sensational - it's impossible.
An "A" lens (set at "A") should work correctly, as you describe. But there's no way for the camera to reliably achieve correct exposure with a pre-"A" lens at anything other than full aperture. So that's what it uses.
If you examine those image you took with the lens set to f22, you'll find they have the same depth of field as images exposed with the lens at f2.8
With a pre-"A" lens mounted (with or without the AF 1.7x adapter), and the camera set to any of the "Auto" modes, the top panel display will show Av. But when the exposure is made, the lens won't stop down.
The only time tha *ist-D will stop down a pre-"A" lens during exposure is if the camera is set to manual exposure mode.
--
I can understand why mankind hasn't given up war. During a war you get to drive tanks through the sides of buildings and shoot foreigners - two things that are usually frowned on during peacetime.
--P.J. O'Rourke
