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+--- Thread: About E-mount licensing (Sigma says: no teleconverter because of licensing) (/showthread.php?tid=4847)
About E-mount licensing (Sigma says: no teleconverter because of licensing) - stoppingdown - 08-13-2020
This review of the Sigma 100-400mm F5-6.3 DG DN OS C...
https://sonyalpha.blog/2020/07/21/sigma-100-400mm-f5-6-3-dg-dn-os-contemporary/
... reports a statement from Sigma:
Quote:Regarding your question on the teleconverter for Sony E mount, yes, your question is quite understandable. As you noticed, yes, we released a new TELE CONVERTER TC-1411/2011 for L-mount camera, but not for Sony E-mount camera, which must be unreasonable for you. As you may already know, we are licensed from Sony to design and produce Sony E-mount lenses, and it must be done in accordance with Sony E-mount specifications and license agreement. In the specifications and agreement, there are no statements on teleconverters. So, this is why we cannot design and produce Sony-E mount teleconverters. So, at this point, we have no concrete plan and schedule for making TELE CONVERTER TC-1411 in Sony E-mount.
It's clearly my fault, but I understood that E-mount specs were open and third-parties didn't need a license for developing lenses.
RE: About E-mount licensing (Sigma says: no teleconverter because of licensing) - Klaus - 08-13-2020
I think it's normal that you have to sign a contract in order to obtain the license - even if it's free of charge.
As a manufacturer, you have to commit to comply to the specification and to be allowed to use the trademark.
RE: About E-mount licensing (Sigma says: no teleconverter because of licensing) - Brightcolours - 08-13-2020
Without licence, manufacturers appear to have no issue labelling lenses as being for Nikon F-mount or Canon EOS/EF-mount...
RE: About E-mount licensing (Sigma says: no teleconverter because of licensing) - Klaus - 08-14-2020
As simple as that:
https://support.d-imaging.sony.co.jp/www/e_mount/en/detail.html
FWIW, I just read that Zeiss never received an official license for X-mount. Quite surprising actually - they released lenses in the very early days there.
RE: About E-mount licensing (Sigma says: no teleconverter because of licensing) - Rover - 08-14-2020
Maybe Sigma just needs to ask Sony for a clarification. No reason not to allow making teleconverters if they're allowed to make lenses.