Most helpful positive review
14 of 15 people found the following review helpful
on 7 January 2014
Be careful. Buying some of these cheap-as-chips EOS adaptors will act as a gateway drug, exposing you to the whole new addiction of trawling eBay for old M42 lenses which cost a mint in their day but can now be picked up for the price of a couple of pints.
As for the adaptor itself, it fits nicely, it works and [being metal] seems fairly decently constructed. I do have a couple of concerns as to how the AF-Confirm chip will stand up to the rigours of usage –it's just held on to the adaptor with two small pins– although I've not had any problems so far.
A couple of things to be aware of, when using this adaptor:
1: The adaptor has an AF-Confirm chip. That means, although you must focus manually, the camera beeps and the autofocus indicators light up in the viewfinder, when you hit the 'sweet spot'. However, I find that this only works with the aperture fully open. Therefore you will have use stop-down metering: focus wide open, then stop down the aperture to take the shot.
2: Theoretically, when using AV mode, you should [after going through the focussing and stopping-down routine with your M42 lens] be able to point and shoot and your EOS should correctly meter the light actually coming through. Unfortunately, in practice this isn't always the case. With some EOS models [for example with my 7D] the light meter automatically compensates for such vagaries as light loss through the metering system and focussing screen and for the transmission characteristics of Canon's lenses, in order to produce the perfect exposure.
What this clever voodoo means in practice is that, your EOS may over- or under-expose when using a manual lens with which the camera is unable to communicate. So, you may have to use exposure compensation, which can vary with whatever aperture you use. For example, with an old Hoya 70-210 zoom lens I have, I have to under-expose by roughly one stop for each stop I close down the aperture.
3: According to the manual, your Canon EOS should display "00" for the aperture, when using a manual lens. This is the camera's way of telling you to use stop-down metering. What I didn't realise is that, the AF-Confirm chip on this kind of adaptor changes that behaviour as the chip actually sends a 'fictitious' aperture setting to the camera. In the case of this adaptor, it tells the camera that the lens is stopped down to ƒ1,4. This confused me for a while as I couldn't understand why my camera was showing a spurious aperture reading which I couldn't change, instead of the expected "00". I thought the adaptor wasn't working properly, but it's OK. This is just a quirk of using an adaptor with a chip attached. You can just ignore this reading and concentrate on the ancient arts of manual metering and stopping down.