M42 on full frame?

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Clarke Kent ;)
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Just a quick question that I can't seem to find an answer on.

I've got a SMC Takumar with the M42 mount adaptor on it to fit to the Canon. Do these work on full frame and crop, or are they for crop sensor only? :thinking:

TIA.
 
Full frame.

M42 is the old 'Pentax screw' fit from 35mm format film, also known as full frame (24x36mm).
 
Full frame.

M42 is the old 'Pentax screw' fit from 35mm format film, also known as full frame (24x36mm).

Excellent, thanks Richard. In which case, it's potentially going to get even more from the lens than a crop sensor body would (usual full frame benefits aside of course)?
 
Ah, ok. It's the 50 1.4 I've got. Really don't want to whack this on the front if it is going to potentially cause a problem :shake:

Quick ways to test for problems:

1. Put the adapter on the back of the lens and focus to both extremes. If any part of the lens protrudes further back than the adapter, then you will likely have issues

2. Set mirror lockup to on and focus the lens to the position where it doesn't extend behind the adapter. Release shutter. Focus lens to the position where it DOES extend behind the adapter. If the mirror hits it on the way down, it's safer (apparently!! Best check though lol).
 
Well after a great deal of searching and reading over the weekend, it appears there is no hard and fast rule on this one.

A lot depends (as has been said) as to how much the rear element extends past the recess on the adapter ring when focussed to infinity.

Unfortunately, mine stepped back too much to be clear but, with a little modification (and a LOT of patience) you can add shims between the mount and the lens to push the whole assembly away from the mirror.

You have to experiment a bit with the thickness to make sure that you don't end up with the lens upside down when mounted (did this too many times to count!) but, with a little perseverance and logic, it is possible.

Anyone looking to try it, just make sure the small metal pin on the back of the lens is depressed by one of the shims or you will lose the ability to choose between manual and auto (for those lenses that have it) on the aperture ring.

In short, you CAN safely mount a 50mm f1.4 SMC Takumar on a 5DMkII (y)

(All I need to do now is use the damn thing :LOL:)
 
In short, you CAN safely mount a 50mm f1.4 SMC Takumar on a 5DMkII (y)

(All I need to do now is use the damn thing :LOL:)

1. And many other manual focus lenses, M42 mount or otherwise. And
2. Yes, will you get on please?:clap:

Oh and by the way...
3. Welcome to the world of "I must buy another MF lens for the interesting bokeh/amazing clarity in such a cheap bit of kit.com"
 
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