m42 adapters: results summary

Bought a 42mm adaptor (second-hand, no-name) from my local photo shop on Saturday (L5 GBP).

Two points to look out for :

1 There were clear signs that the little screw (holds the M42 lens in place) had jammed the Minolta bayonet and someone had had quite a time getting the adaptor off the camera. (I have removed the screw and WON'T be using it!).

2 The clearance between the camera's lens contact pins and the metal of the adaptor was so small as to be invisible. I could not see the pins depress, but even so, I was not prepared to risk it. I machined away the adaptor in the area of the pins to give a visible 0.5mm clearance all the way and now it is fine.

Those who have seen my posts about horrible old lenses may wonder why I bought the adaptor. Two reasons : 1 - I have dragged my macro extension bellows out of the loft for a play and that has 42mm fittings (each end) and 2 - I found an old 500mm f8 mirror lens that I had forgotten about, so I thought that I would try it (there's not much to go wrong with mirrors - they are either great or rubbish, with nothing in between) and it seems OK tested on a very dull day.

thanks for the bump damian and the e-mail info.

It seems like it for general use, put it in some other lenses to fit your KM.

Just if anyone is interested. I got some ex-russian leneses in the post: 85/2, 37/2.8, 50/2.8 macro

The 50/2.8 is for a head to head with my Min 50/3.5

The 85/2 is just for fun and bokeh playing. Should have kept the Min 85/1.4 for a few more weeks huh!!

Might keep them. Might just test them, report on how to use M42s on a KM5D or 7D and then eBay them off at the price I paid for them. They're just a bit of fun.

Might even track down a Pentax SMC 50/1.4 to test against my two Minolta 50/1.4s (original & new) in the Bokeh and sharpest review I'm in the middle of.

Edited by DcapVividOptic - 21 March 2006 at 14:21

Jarenas
Whatever works on the 5D also applies to the 7D.

I bought a Minolta/M42 adapter from Hong Kong on ebay a few weeks ago.

The apapter seems reasonably well made/finished and fitted my 5000 fine, but would not fully engage with my 5D - not a great problem as it worked fine where it was -a couple of mm off register. last night I tested which of the bayonet flanges was stopping full engagement (it was the one below the small hole as you look at the back of the adapter) and took the front off that flange with a file.

Once cleaned up the adapter fits very nicely and the catch engages in the hole.

In summary: The Hong Kong adapters work fine as delivered, but don't click into place on a 5D. They can be easily modified (without special tools) to fit snugly.

Bob

Timbuctoo wrote: DcapVividOptic - Tim here. So your adaptor worked on the 7D without any modifications? What one do you use and where did you get it from? Do they affect the metering?

Actually I had trouble getting one of them off the 7D last night. So I won't recommend or otherwise my source until I've tried the other two I got from same place. I have three rings (3rd lens coming soon), the two I have on the 37/2.8 & 85/2 mount/unmount from the 5D fine. 7D too tight for me to want to try again. ODD! Should be the same mount, maybe the bits inside the camera away from the mount are a different clearance on the two cameras?

Anyone else got 5D & 7D and have differences here?