m42 adapters: results summary

I bought a thin enough chip-less adapter from ebay seller big_is and also thin enough chipped from ebay seller roxsen. The chipped was totaly smeared with hot glue. After trying it on one camera (A77) one of the camera's lens contact got stuck in in position and the camera could not find any lens. I found the problem and peeled of the hot-glue from the camera with a needle. I removed the chip from the roxsen adapter and use it as non-chipped.

I've been very happy with the relatively cheap M42 adapters I picked up on Ebay and use on my Jupiter and Helios lenses.

Dorset Mike wrote: The main purpose of the chip is to make the camera "see" the lens. In very basic terms when the camera is switched on the processor initially checks each camera function and also sends a signal to the contacts on the lens, the chip responds saying in effect yes there is a lens fitted and my maximum aperture is xx (xx = an F value programmed into the chip, usually during manufacture) If the camera sees this then the focus confirm will function, if the adapter has no chip, it can not respond to the camera, hence the focus confirm function is not made available.

I order a chipped adaptor, but my lens is an f/1.4, i think most chipped adaptors are program max at f/1.7, you think it'll meter right?

Arkku wrote: re. camera error, do you mean that you get the error when you take a picture or just when you try to use the adapter? If it only occurs when you take a picture, are you sure that you have selected the largest available aperture setting on the camera (regardless of whether or not it matches your lens)? If you select any smaller aperture, the camera will try to actuate the aperture mechanically and this may sometimes cause an error if the actuator hits the lens…

Ah, I guess that could be it, I did shoot with the aperture setting was not the widest (I tried to match the actual I used, and I guess that could be it!

Thanks!!

Hmm, the sample photos says M42 135mm with A700.
But EXIF says Canon 85mm, probably auto focus...
Funny.

BTW, I have few Chinese made adaptors (set to 135mm) they work fine for A700, but for some reason they intermittently give "Camera error" on A900...
Anyone else have this issue?

I appreciate the above replies, thanks guys.

Yes. But they do not communicate with the lenses; the focus confirmation is a function of the camera. For whatever reason, the confirm won't work unless the adapter is chipped, even though there is no critical communication. I would think they could have easily made the function work without the need for a chip, but they didn't.

There are three advantages to the chipped adapters: Focus confirm, aperture mode auto exposure (at least is the case with my A200), and the stabilization function if the adapter is programmed with the correct focal length. After using both types of adapters, I've been buying only the non-chipped and shooting in manual. I find the exposures more accurate (seems the auto exposure has difficulty when lens is stopped down). It took a little time to get used to it, but now I prefer.