Tamron 150 600 woes

[Stephen Melvin]

One thing that's worth a mention is that Canon's mount is long out of patent protection. Contracts, of course, are a separate issue.

I wonder why I've never had an issue with a Tokina lens. I mean, other than the focus and zoom rings turning the wrong direction.

 

[Stephen Melvin]

Another "reverse engineering" thing that bit me was the Nikon-Canon adapter I own and works perfectly on my Mk II. It has the chip on it for AF confirm.

It absolutely fails on my Mk III, to the point where I cannot use it at all.

 

[wickidwombat]

I'm amazed that such sweeping decisions about if a lens is good or not is being based on
DOT TUNE!

Seriously Dude. If your sellers found this out I bet they would stop selling to you, I know I would.

you really need to firstly do some good research on AFMA try start with the article neuro wrote on the digital picture

if your really want to go crazy with AFMA really the only option is Focal and still that needs to be setup correctly and the instructions need to be followed or you will make the lens worse.

 

[scottkinfw]

With the exception of my cheapo Samyang 14mm 2.8, all my lenses are L and all need some afma. You are lucky I guess.

sek

I knew it was a problem because images were not in focus on my 60d.

Yes, i could afma on 5d3 but I refuse to spend 1000£ on a lens that doesn't work on both my bodies. I have 9 lenses all of which are calibrated perfectly (no afma require at all) across both bodies.

 

[tat3406]

Is that the focal length more longer, the higher percentage the lens need to AFMA?

 

[dcm]

Is that the focal length more longer, the higher percentage the lens need to AFMA?

I think its really about narrow depths of field, particularly near MFD, which faster apertures and/or longer focal lengths exacerbate.

At 600mm on my Tamron 150-600, at 20 feet you have a DOF of 2" with f/11 and 1" with f/8 so it matters on long lenses even with small apertures. The 135L has a similar 2" depth of field at 10 feet with f/2. The 50L has a 2" depth of field at 5 feet with f/1.2. These are all about twice MFD.

Most kit lenses aren't that fast or that long so they tend to be acceptable without AFMA. But fast lenses and long telephotos can benefit from AFMA.