Sigma 50-100mm f/1.8 + Fringer: How good is the AF?

Hi all,

I'm considering adding the Sigma 50-100mm f/1.8 lens to my ever expanding lineup of lenses, for general portraiture and low-light shooting.

I'm wondering however how the autofocus of it (when using with the Fringer 2 adapter of course) will compare to the Fuji 50-140mm f/2.8.

I'll be using the lens on an X-H1 probably, because of the IBIS, but may also put it on my X-T3 for the improved AF.

The reason I'm considering adding the Sigma 50-100mm when I already have the Fuji 50-140mm is because of the extra stop of light for low-light shooting, and also a bit shallower depth of field for portraits.

What do people think? Anyone who has experience with this lens adapted on a Fuji body? Anyone who has used this lens next to the Fuji 50-140mm and would be able to compare based on their own experience?

Both are very different type of lenses.
Usually a zoom lense of this kind is at least partially for sports shooting,
but 50-100 is for image quality only.

50-100's AF is not horribly slow but slow even with a DSLR like 5D4.
When used with Fringer2+X-T3, and only when there was a lot of contrast
in focus area, it performs like DSLR. But in most case it requires
several search movements and it's not quick.

IMHO Sigma 50-100/1.8 is a portraiture special after all.
As far as I remember, in terms of AF, 50-100 cannot compete
with XF50-140 at all, even in low light situation.

So, I cannot recommend it for X-T2 generation,
because average person may feel AF is faulty.
I myself prefer 50-100 because of its dancing light image.
I once owned both lenses and now only have 50-100.

Thanks for your answer! This is very helpful.

I don't shoot very often the kind of events or parties where I meet the limits or the 50-140mm, and don't shoot portrait very often yet, but lack of IBIS on the X-T3 and OIS in this lens made me feel that the X-H1 would be a better body for it.

If the AF is like you say, then probably not!

If Sigma would ever start releasing lenses for Fuji X-Mount then I may hope they'll release this one for X-Mount too...

OK, not so likely as they haven't even released it yet for EF-M mount, it's not "made for mirrorless". But the lens might benefit from an upgrade for mirrorless APS-C cameras and release for Fuji and Sony APS-C mounts...

Anyway, for now I'll put this lens on the backburner and will first see what Fuji will bring out next year!

Fuji Maine wrote:

So for the end result of what the sigma delivers optically and the price I'd say it's a no brainer, especially if you are much more into photo than video. Plus it's going to cost you quite a bit less.

Thanks for your reply!

I am much more into photo than video, true, but I already own the 50-140mm and the Sigma 50-100mm would be an additional lens. As such, it's not going to cost me less and would always face competition against the 50-140mm.

It would be a lens for more limited uses, when I need the shallower depth of field for a portrait, or the extra stop of light.

Shooting people at a party (with a camera ) -- That's when there's low light and AF needs to be good, instead of hunting around. I don't shoot that kind of thing very often and especially not with the current pandemic, so it's not a main thing for me -- I love Fuji for almost everything I do with my cameras so the AF being not best-of-the-best has not yet pushed me away for the relatively few times I feel its limits.

The other negative is that Fringer is unable to communicate focus speed and sensitivity settings from a Fuji body to the lens so the settings do nothing.

Are you sure about this as I shoot M on an X-T3 with a Fringer EF-XF Pro and can select whatever aperture or speed I want for the Sigma 50-100.

FarmerOne wrote:

The other negative is that Fringer is unable to communicate focus speed and sensitivity settings from a Fuji body to the lens so the settings do nothing.

Are you sure about this as I shoot M on an X-T3 with a Fringer EF-XF Pro and can select whatever aperture or speed I want for the Sigma 50-100.

He is talking about these things:

https://fujifilm-dsc.com/en/manual/x-pro2/menu_shooting/af-c_custom_setting/index.html

I know most people haven't even opened that horrifying menu, but it is quite useful to make the AF-C usable.

OrigamiCactus wrote:

FarmerOne wrote:

The other negative is that Fringer is unable to communicate focus speed and sensitivity settings from a Fuji body to the lens so the settings do nothing.

Are you sure about this as I shoot M on an X-T3 with a Fringer EF-XF Pro and can select whatever aperture or speed I want for the Sigma 50-100.

He is talking about these things:

https://fujifilm-dsc.com/en/manual/x-pro2/menu_shooting/af-c_custom_setting/index.html

I know most people haven't even opened that horrifying menu, but it is quite useful to make the AF-C usable.

Ah yes, thanks, but hardly ever use AF-C .

Any updates here? Did you end up buying the lens and if so how does it fare for you?