confused about M42 to EOS adapter...

[Katzer1]

Hi,
I asked it on the accessories section, but I am starting to think this forum is probably a more suitable fit.
Here it goes:

I just ordered a Peleng fish-eye, which comes with a simple M42 to EOS adapter (the 10$ one) which according to the seller doesn't feature AF confirmation.

Now I understand that when stopped down a bit, the DOF on the 8mm Peleng is wide enough to cover most focusing errors, but still, it might be usefull or at least if a m42 lens would pass by my way.

I started to look at the ebay offerings, ended up getting confused about the aperture flang.
Some have it, some don't.

As I understood it: no mount adapter would enable AF, but some would give AF confirmation.
Aperture cannot be controlled from the camera with any adapter.
The flang is ... well I still not sure what it is for.
Some M42 lenses have an aperture ring , or all of them?
When turning the ring on modern lenses, does it really close the aperture diaphgram? or only when an image is taken or the dof preview is pressed.

So I am confused... is there any other pivotal featrure that I should make sure I am getting in this adapter?
Do you have a specific adapter in mind to suggest?

Thanks:)
Erez

[condyk]

I've just bought mine off ebay in the past and all seem to work fine. Put the Canon in AV mode and use the aperture ring on the lens to open and close the aperture. Start wide open so viewfinder is bright and you can see better, focus, stop down as required and snap. Easy! A split focus screen helps a lot. Some adapters can confirm AF after a fashion and seem popular but they won't enable AF as there is no motor or electrics in the lens anyway. You can't control aperture in the camera.

[AirBrontosaurus]

The cheap one (which is coming with the lens) is exactly what you need. I have the Peleng as well, and I can tell you that all of the stuff on the expensive adapters are unnecessary.

As you said, the DOF of the Peleng make focus confirmation rather useless. At f/10, pretty much everything is in focus, so you don't have to worry about it. Just eyeball it in the viewfinder and you'll be set.

The Peleng has the aperture ring AND rapid stop-down control on the lens, so you don't need it on your mount. As you rightly said before, the lens is completely manual, so aperture CANNOT be control by the camera, not can aperture data be transmitted.

I believe the aperture flange is more important for other M42 lenses, but not the Peleng. Enjoy your awesome lens!

[AirBrontosaurus]

Start wide open so viewfinder is bright and you can see better, focus, stop down as required and snap.

You can actually set the aperture on the lens, and then twist the Lock/Unlock ring to open the aperture back up to wide open. Thne, you just focus, twist the ring again, and shoot! You don't even have to take your eye off of the viewfinder.

[Andy_T]

Erez,

though I'm not much of an expert myself, some points here ...

AF confirmation is really a feature of the camera, when it believes that it has a valid EF lens mounted. So there are some adapters with a little custom-made chip (wired to contacts that fit the contacts in the camera body) that pretends to the camera (via electronic signals) that a valid EF lens is mounted. In that case, the camera gives an audible and visible signal when the AF sensor recognizes correct focus.

The aperture flange ... this is needed to stop down the lens. Normally, when you focus and compose the image, you want the image to be as bright as possible (so you use the lens wide open), but you want to stop the lens down for shooting the picture. On an EF lens, all this is controlled electronically by the camera. The moment you press the trigger, the lens is stopped down electronically to the selected aperture and the image is taken.

On manual lenses, there are some ways to do that ... the first and oldest would be 'preset' aperture ... you have to manually turn a ring to stop down the lens. My Jupiter-9 has 3 rings ... one to focus, one to limit the aperture and the third one to actually stop down the lens to the value you set as limit. Quite cumbersome.

Newer manual lenses either have a lever that stops down the lens when you activate it, or they have a pin that is activated by the camera when you press the trigger. The flange collar can help you with those.

I have tried out a few adapters ... and I don't find any flaw with using a generic 15$ eBay offering ... it's really not rocket science to machine a piece of metal with two threads. Of course, the manufacturers of the 180$ Novoflex adapters would tell you differently, but until you really have problem with the one you have, I don't see many problems...

So my suggestion is ... go out and take some images!!!

Best regards,
Andy

[Katzer1]

The cheap one (which is coming with the lens) is exactly what you need. I have the Peleng as well, and I can tell you that all of the stuff on the expensive adapters are unnecessary.

As you said, the DOF of the Peleng make focus confirmation rather useless. At f/10, pretty much everything is in focus, so you don't have to worry about it. Just eyeball it in the viewfinder and you'll be set.

The Peleng has the aperture ring AND rapid stop-down control on the lens, so you don't need it on your mount. As you rightly said before, the lens is completely manual, so aperture CANNOT be control by the camera, not can aperture data be transmitted.

I believe the aperture flange is more important for other M42 lenses, but not the Peleng. Enjoy your awesome lens!

Thanks AirBrontosaurus:) that is what I was looking for.
I read your ealer posts about the peleng and they really helped me make up my mind about buying this lens.
Erez

[Katzer1]

Erez,

though I'm not much of an expert myself, some points here ...

AF confirmation is really a feature of the camera, when it believes that it has a valid EF lens mounted. So there are some adapters with a little custom-made chip (wired to contacts that fit the contacts in the camera body) that pretends to the camera (via electronic signals) that a valid EF lens is mounted. In that case, the camera gives an audible and visible signal when the AF sensor recognizes correct focus.

The aperture flange ... this is needed to stop down the lens. Normally, when you focus and compose the image, you want the image to be as bright as possible (so you use the lens wide open), but you want to stop the lens down for shooting the picture. On an EF lens, all this is controlled electronically by the camera. The moment you press the trigger, the lens is stopped down electronically to the selected aperture and the image is taken.

On manual lenses, there are some ways to do that ... the first and oldest would be 'preset' aperture ... you have to manually turn a ring to stop down the lens. My Jupiter-9 has 3 rings ... one to focus, one to limit the aperture and the third one to actually stop down the lens to the value you set as limit. Quite cumbersome.

Newer manual lenses either have a lever that stops down the lens when you activate it, or they have a pin that is activated by the camera when you press the trigger. The flange collar can help you with those.


So the camera body presses the adapter's pin, and the adapter presses the lenses pin?



I have tried out a few adapters ... and I don't find any flaw with using a generic 15$ eBay offering ... it's really not rocket science to machine a piece of metal with two threads. Of course, the manufacturers of the 180$ Novoflex adapters would tell you differently, but until you really have problem with the one you have, I don't see many problems...

So my suggestion is ... go out and take some images!!!

Best regards,
Andy

I will as soon as I get that lens!
Thank you for helping clearing things out for me :)
Erez

[Andy_T]

So the camera body presses the adapter's pin, and the adapter presses the lenses pin?


That is what I suspect.

Of course, while the camera can have some kind of mechanism to push the pin when the shutter is pressed, the adapter can only constantly press the pin. In that case, you have a lever on the lens between 'have camera push pin' and 'ignore camera push pin', and by toggling between those two, you effectively stop down the lens.

At least, that's the way my CZJ 135/3.5 works (the later version, not the earlier 'zebra' model that is missing this pin)

If you look at the image, the little lever is below the right red arrow...

http://www.aprd31.dsl.pipex.com/articles/czj135svc/images/1.jpg

Best regards,
Andy

[olly_k]

I will say be carefull with some adaptors.. I just purchased one that shorts out the higher camera contacts which results in an error code :evil: I think a bit of tape should sort it out though (hopefully)...

Just changing the subject a little bit, (hope you don't mind OP) can anyone here advise what lens's to go for and what to avoid? I just got a Vivitar 135 f2.8 and have been left a little bit dissapointed, even at smaller apatures... It suffers from low contrast and too much fringing at higher contrasts also bokeh not very nice - I was told Vivitar and Pentax etc were a better amongst lens makers but not sure now!

[Andy_T]

I just got a Vivitar 135 f2.8 and have been left a little bit dissapointed, even at smaller apatures... It suffers from low contrast and too much fringing at higher contrasts also bokeh not very nice - I was told Vivitar and Pentax etc were a better amongst lens makers but not sure now!

Hmmm ... just did a very quick and dirty, totally unscientific test ... opened www.ebay.com and enteres 'Vivitar 135 2.8', 'Pentax 135 2.8' and 'Zeiss 135 2.8' as search terms ...

Vivitar average price ... 10 $
Pentax average price ... 50 $
Zeiss average price ... 150 $

OK, not really representative due to the small sample size, but what it tells me is that there *are* some price (and most likely quality) differences...

Best regards,
Andy

[olly_k]

Hmmm ... just did a very quick and dirty, totally unscientific test ... opened www.ebay.com (http://www.ebay.com) and enteres 'Vivitar 135 2.8', 'Pentax 135 2.8' and 'Zeiss 135 2.8' as search terms ...

Vivitar average price ... 10 $
Pentax average price ... 50 $
Zeiss average price ... 150 $

OK, not really representative due to the small sample size, but what it tells me is that there *are* some price (and most likely quality) differences...

Best regards,
Andy

yeah kind of says it all really doesn't it! Maybe I ought take future advice with a pinch of salt!