M42 Teleconverter with most internal clearance.

vroger · Expire: 2016-10-21

I never said I wasn't a bit crazy.. I'm wondering if there is a M42 Teleconverter that has more internal clearance than others. use case is to use a lens that extends to far for my Canon 5D, and hits the mirror. Now, I could also use a Canon EOS EF Teleconverter, but I assume the M42 devices were designed to be used with more M42 lenses, hence why I was hopping some would be deeper.

Yes, I know there will be some level of IQ hit, but this is so I can get some FF benefit with Shallow DOF. That being said, I want to avoid a teleconverter that has bad IQ.

Thanks.

Aanything · Expire: 2014-05-30

I wouldn't consider this as a good option: my experience with various m42 TC's wasn't very good, to be extremely fair.
Also, consider that a 1.4/50 with a 2xTC Will behave like a 2.8/100. And longer lenses usually have more clearance Than normal/wides: so, in this case, I'd go directly for a 2.8/100 without the hassle and impact in iq that a tc would give.
Another thing you might consider, if you want those m42s so badly, is mirror shaving your camera: there are many members here Who did it without problems and that could provide info on the process.

visualopsins · Expire: 2025-04-11

Actually it is the mirror that hits the lens.

I think nearly any M42 TC will have enough clearance for M42 lens. I think nearly any M42 TC will not get hit by mirror. I base on not hearing of any problem -- not the best criteria. Laughing

The best TC I tried have 7 elements, such as Komura and one by Spiratone. However, as Aanything experienced so have I -- TCs are not very good; the image is degraded significant; the center of the image can be okay, but edges are usually not so good. I have got as good or better image quality using the lens by itself and cropping the image.

Does your 5D have the mirror-stiffening fix? (free from Canon) I ask because mine does -- my camera's mirror has hit lens probably at least 100 times without any damage -- with only one lens, Takumar 3.5/24, causing camera ERR indicating problem with mirror swing. I use all the lenses in my signature. The 50mm & wider lenses get hit, only sometimes, at infinity. I've used them for several years without any camera problems other than the occasional hit, which doesn't seem to hurt anything.

vroger · Expire: 2016-10-21

vroger · Expire: 2016-10-21

visualopsins · Expire: 2025-04-11

The other thing is non-infinity focus usually presents no problems -- the lenses I use at infinity are usually not wide angles.

I used to think for landscapes use wide angle at infinity, however, the details get really tiny and very far away. Stitching a panorama made from longer lens gives much much better results for that kind of work -- wide-angle infinity landscapes -- or larger format camera such as 8x10". Very Happy

Wide angle lens is meant for showing a close up of something, while including a lot of its environment, extending to infinity sometimes -- the best wide angle images show something close in the foreground, in its environment that extends to infinity. In that case, focus is on the close-in subject, not infinity.