NatureScapes.net Forums

Sigma just introduced a 20mm f/1.4 and 24mm f/1.4 Art lenses for Sony mirrorless and they are marketing them to astro photographers:
https://www.dpreview.com/news/678539700 ... nd-e-mount
https://www.dpreview.com/news/534490770 ... ra-systems

I’m very interested in the 20. 
Small problem - I have the Nikon Z cameras. 
Any chance of a converter or will Sigma release with a Z mount?

wdg wrote:I’m very interested in the 20. 
Small problem - I have the Nikon Z cameras. 
Any chance of a converter or will Sigma release with a Z mount?

Same problem, but I have the Megadap 21 adapter, it works well with Sony lenses, although third-party lenses remain to be seen.

RF mount??

Wildflower-nut wrote:RF mount??

No RF mount. I will buy the new Sigma 24mm f1.4 if there will be RF mount. I was waiting for the interesting Canon RF 24mm f1.8 STM, but it seems it has a very strong coma for night photography.

wdg wrote:I’m very interested in the 20. 
Small problem - I have the Nikon Z cameras. 
Any chance of a converter or will Sigma release with a Z mount?

Good article on adapting Sony E-mount lenses to Nikon Z mount cameras using the Techart adapter:
https://mirrorlesscomparison.com/storie ... n-adapter/

Note that neither Canon nor Nikon licenses their mount to third party manufacturers like Sigma and Tamron while pretty much all of the others do including Sony. So when you buy a Sony mount Sigma lens, the mount conforms exactly both mechanically and electronically to the Sony specification. If and when a similar lens is available for Canon or Nikon, it is going to have a reverse engineered mount (mechanically and electronically).

E.J. Peiker wrote:Note that neither Canon nor Nikon licenses their mount to third party manufacturers like Sigma and Tamron while pretty much all of the others do including Sony.  So when you buy a Sony mount Sigma lens, the mount conforms exactly both mechanically and electronically to the Sony specification.  If and when a similar lens is available for Canon or Nikon, it is going to have a reverse engineered mount (mechanically and electronically).

Do you know if the Sigma or Tamron lenses for reflex with Canon EF or Nikon F that exist, were licensed or reverse engineered? I do not understand why they do not make now for RF and Z mounts, if they ever did for EF and F. And other independent lenses manufacturers brands make them.

imagenes_vivas wrote:

E.J. Peiker wrote:Note that neither Canon nor Nikon licenses their mount to third party manufacturers like Sigma and Tamron while pretty much all of the others do including Sony.  So when you buy a Sony mount Sigma lens, the mount conforms exactly both mechanically and electronically to the Sony specification.  If and when a similar lens is available for Canon or Nikon, it is going to have a reverse engineered mount (mechanically and electronically).

Do you know if the Sigma or Tamron lenses for reflex with Canon EF or Nikon F that exist, were licensed or reverse engineered? I do not understand why they do not make now for RF and Z mounts, if they ever did for EF and F. And other independent lenses manufacturers brands make them.

100% reverse engineered.  Neither Canon nor Nikon licensed their DSLR mounts either.  This is why occasionally when new cameras came out, Sigma and Tamron lenses suddenly didn't work anymore and they had to be sent in for firmware or in some cases even hardware updates.  Sigma and Tamron later made life a bit easier for themselves by coming up with the lens docks that allowed newer lenses to be updated by the user.

There are many legal hurdles that have to be crossed before T and S can offer even reverse engineered lenses without risk of copyright and patent infringement.

Question for someone more knowledgeable
As I said I’m interested in the sigma 20mm - main reason is the Astro angle.
The previews show a filter holder at the back of the lens - am I correct to believe I can add clip filters?
H-alpha or light pollution?
Would they be something that Astronomik makes?
I haven’t seen much on the back filter capabilities/requirements.
Thanks for help.
I also see that Megadap has a new adapter that claims compatibility for Z cameras. Any thoughts?

It’s a filter holder that you put gel filters into but it also takes standard 82mm filters on the front.

I think I wait for tests by someone I trust. Many of these f1.4 lenses over they years have either vignetting or coma issues that make you stop down to f2 or 2.8 before you can use it for astro. Hopefully that is not the case here