SAL 20TC (and SAL14TC) compatibility

[mischof67]

I have checked the Sony web site to seek an answer, it appears there may be only 4 lenses these items are suitable for use with. I'm puzzled, because I used the 20TC last week with an old Minolta APO 300mm F2.8 I managed to source. Having seen the web site, I wondered if the TC would be OK to mount with the Zeiss 135 F18 I have with my A99. Just asking for some confirmation from the experts out there. 

[Portmixus]

I understand you are puzzled!

But you need to understand the Minolta history for why it did work with your 300mm lens.

The Sony TCs are reincarnations of the Minolta TCs. The Minolta TCs have different gearing or only 5 contact pins, depending on the generation. But the latest Minolta (D) Tcs are the direct predecessors of the Sony TCs and are duplicates.

But Sony (as far as I know) only mentions compatibility with Sony lenses but as you understand by know, as they are reincarnations of the Minolta TCs, it works with selected lenses also from Minolta. Typically (but not limited to) the white Minolta G lenses (as the one you have!) are suitable for use with this TC, but also for instance the 135mm F2.8 STF, 200mm F4 G macro.

But to answer your question, it is not possible to physically mount the Zeiss 135 F1.8 on the SAL20TC. This teleconverter has a "special" protruding lenselement and does not allow most lenses to be mounted on.

You'll need a (very good) generic TC to do this. I'm a fan of the Kenko DGX series (although, but I'm not a fan of 2.0TCs. Had both the SAL20TC and Tamron MC7 2x TC. Now I have the Kenko 1.4x DGX, the optical quality is very very good! 

[mischof67]

Hi Portmixus, thanks very much for the excellent response. I'll keep my eye out for the TC you have mentioned. Do I assume correctly that the Kenko TC you have mentioned will attach to the 135 Zeiss and to other Sony lenses not listed as being compatible with the genuine Sony TC's? I'm glad I never tried to attach the SAL20 TC and the Zeiss together, I would hate to have caused any damage to what is the beautiful piece of engineering I've managed to afford. The 135 Zeiss is a dream. I would have loved to remain with genuine Sony kit, alas, if they won't provide equipment to help their existing and loyal customers, then they will have to accept they will loose sales. While I'm not about to off load the SAL20TC, sometimes I would like the ability to have a bit of extra reach with the 135 and retain it's aperture. (I also have the 85 and 50 Zeiss lenses all of which I prefer to use in the low light situations at the live music gigs I like to attend.)

[Portmixus]

Hi!

I looked up the entire list for you:

• 70-200mm f/2.8
• 300mm f/2.8
• 135mm f/2.8 STF (manual focus)

Only the following Minolta lenses are compatible:

• 300mm f/2.8 (D) SSM 
• 70-200mm f/2.8 (D) SSM
• 200 f/2.8 APO G
• 300 f/2.8 APO G
• 300 f/4 APO G
• 400 f/4.5 APO G
• 600 f/4 APO G

Note: The following Minolta or Sony lenses can only be used in Manual Focus mode:

• 70-400mm f/4-5.6 G SSM
• 70-300mm f/4.5-5.6 Telephoto Lens
• 135mm STF f/2.8 [T4.5]
• 200mm f/4 Macro G
• 400 f/4.5 APO G
• 600 f/4 APO G

Please keep in mind that the use of a TC goes along with loss of light. For a 1.4TC that's 1 stop of light (turning your 135 F1.8 into an 202mm F2.5 and when you use a 2x TC, you even lose 2 stops making your Zeiss 135mm a 270mm F5 lens.

So a 2x TC with your zeiss lens is not very interesting but a 1.4TC might do the trick. But to be honest, You could as well use a crop-body if you have one lying around 

[mischof67]

Thanks again Portmixus, the 1.4TC with the Zeiss 135 is the combination I was thinking of. I also own a A77v1, (along with an A700 and Minolta 7D). I generally take both of the latest bodies to gigs. I may have source the 1.4TC you speak about. Will it work with any Sony alpha fit lens? 

[Portmixus]

Yes it's what they call a "generic" TC which will work with any lens!

Look for a Kenko 1.4x DGX adapter. Only complaint I have is vignetting with the Minolta 400mm F4.5 on a Full-Frame body. I'm generally a fan of vignet, but it's quite obtrusive (but manageable). Quality is beautiful. 

[mischof67 · Accepted solution]

Thank you for your help and advice.