So I own a Minolta XD7 (XD11 for American users) and few months ago I had the opportunity to by a Sigma 400mm f8 mirror lens in MD mount but how do you use this correctly on a XD7?? There is no diaphragm in this lens thus no extra lug to let the camera know there is one. So i'm guessing the camera just measuring the incoming light and does not take any account of the missing diaphragm? Do I have to use Automode, Aperture Priority Mode or Manual Mode?
I dry fired it on a XG2 and installed a 35mm lens who gave me 1/60 sec on f8 and so did the 400mm when it looked trough it so the XG2 just measures the incoming light I guess but what about the XD7?
I bought this lens new in box for about 10 euro from a sale-out of a photo shop so it's a great deal anyhow.
Catadioptric lenses, such as the one you have acquired, are fixed aperture lenses. The internal reflectors take all of the space, thus rendering no room for an aperture assembly. And, yes, most cat lenses are f/8.
In general:
Using a mirror lens on a TTL-metering camera would need to use the camera in aperture-stepped-down modus, if you want to meter by means of the camera.
This tells the camera that the current aperture is the one used for the exposure, the same time disengaging any aperture control if available at that camera.
Depending on the camera one then could employ manual metering, or even auto-exposure which would control shutter speed.
And some cat lenses extended far enough into the body to block the viewing mirror's travel. Mirror lockup vapability could be required. Definitely a strong consideration.
So I own a Minolta XD7 (XD11 for American users) and few months ago I had the opportunity to by a Sigma 400mm f8 mirror lens in MD mount but how do you use this correctly on a XD7?? There is no diaphragm in this lens thus no extra lug to let the camera know there is one. So i'm guessing the camera just measuring the incoming light and does not take any account of the missing diaphragm? Do I have to use Automode, Aperture Priority Mode or Manual Mode?
You guessed right!
You an use the XD in aperture priority or manual. The meter should give you the same shutter speed for either.
In manual you meter for f8 & set the speed. In Auto the camera sets the speed.
Hi Uncle goose! I know this is an old thread but, I have a small passion for mirror lenses and have never heard/read anything about your lens. Isn't it maybe a 400 F 5,6 ??? If indeed it is a F 8, I'd be really really interested in some pictures and of course I'd like to buy that lens from you. Please, let me know, and thanks a lot. Philippe