m42-eos adapter stop down?

[franklin_polk]

Hello

I've been looking at getting an m42 for some of my old lenses. I have

a (m42) lens that needs for the stop down pin to be pressed in order

for the aperture to be adjusted. However, from what I have seen in

the pictures of the adapters from places like Fotodiox, it seems they

don't have a plate/bar/something that would press this pin and allow

for the aperture to be adjusted. Does anyone have any workarounds so

that I could use my lens on this adapter and have it work properly, or

could point me to adapters that have this plate/bar/something?

Thanks.

[del_gray]

I haven't heard of any adaptor that performs this function, even in going from M42 to Pentax K mount, let alone Canon. I believe most (?) M42 lenses have a switch that makes the aperture control manual (at least my Pentax lenses do), so you can focus wide open, then meter with the aperture manually stopped down with the aperture ring on the lens. On a Canon body the shutter will correctly set to match the stopped down aperture. It isn't ideal, but I haven't heard of any other adaptor that makes it any easier.

[beerbrain_ronny_perry]

On the m42 lens that dont have the Auto/manual switch, I unscrewed the back of lens plate, and disengaged/ripped out,the iris lever.Im just interested in using the lens stopped down, so I dont care if the auto diaphram works or not, so I ripped it out, works great in AV mode on 20D.If you have a lens with the auto/manual switch your OK.

[bobatkins]

I have an M42->EOS adapter that depresses the stop down pin. It does it with a very thin flange at the end of the threaded section.

 

Don't ask me where I got it from. I think it came with a lens I bought.

 

However such adapters do exist.

 

I've also done the "jam up the mechanism" trick on the lens. Not usually too difficult.

[jsbc]

This is one of the sources for such adapters.

 

http://www.rugift.com/photocameras/canon_eos_lens_adapter.htm

 

I have bought/used their adapters, but not otherwise related.

[shambrick007]

I glued my pins.

[jimstrutz]

My adapter presses the pin as well. I was surprised the first time I heard that some adapters don't do this.

[glen peterson]

I modified my eos-m42 adapter, to depress the pin on some of my lenses, and it works well with all of my m42 lenses.

[larry h.]

Franklin, I asked this exact question about a year ago. The three options were to buy a new adapter that depressed the stop-down pin, stuff some black paper in the adapter to depress the pin, or glue the pin down. I used the paper trick. Here's a big warning that I learned: Do not stuff paper in there if you plan to use teleconverters; you may not get the adapter and teleconverter apart. That may only be the case with the Tamron Adaptall teleconverters I used, but I am not sure. So, I switched to the glue idea instead; it only affects the adapter, not the lens. Best of luck.