Vintage lens info

[Carpy2001]

Hi all me again lol.
I am using the Pentax smc M 50mm f1.7 on my Olympus M43 camera at the minute, I have it mounted on a dumb adapter.
The lens is vintage 35mm or full frame, so the 50mm has a 100mm equivelent fov on my Olympus camera?, I have told the cameras IBIS it has a 50mm lens attached which I beleive is right?.

My question is.

Should I use the standard dumb adapter with this lens or should I be using a focal reducer/speed booster??.
Being a bit slow on the uptake theses days, I am not quite getting my head around the difference lol.

Cheers Andy

 

[woof woof]

Speed reducer/boosters weren't about when I was using film era lenes on MFT but AFAIK it'll will try and make the lens look like a FF 50mm lens again, so that'd be 25mm on MFT (but this would depend on the spec of the reducer/speed booster) rather than looking like a 100mm lens when mounted on MFT. AFAIK.

I think it's entirely up to you. I really enjoyed using a 50mm with a dumb adapter on MFT and as these dumb adapters are cheap I think I'd have two adapters, a cheap dumb one and a reducer/booster giving you two lenses in one.

 

[GreenNinja67]

I gave them both to you Andy.

Use them as you are, that's the correct way.

If you want to make it look like a 50mm lens then just buy a 24mm manual focus lens and mount it to the adaptor.

 

[Petrochemist]

Use it either on the dumb adapter for a 100mm FOV (& with IBIS told it's 50mm as you are) or on the speedbooster if you want a wider FOV, when for best results you probably want to tell IBIS the focal length is ~35mm (50mm for the lens times 0.7 for the booster is 35mm for the total optics)

I've had a M50/1.7 for over 40 years & and now have several - great lenses