The new 100mm FE STF lens

[SPtheALIEN]

I did not see a post here about this lens.

It's good. So sharp. And if you're used to the a-mount version--the surprising thing is that it auto focuses. If you have any questions (other than image samples--can't do that yet), ask away. It's likely going to be Sony's least understood lens. As of now, it reports the value in T-stops (rather than what most are used to--f-stops).

[Jay]

I posted an article here http://sonyalphalab.com/new-sony-fe-...m-radio-flash/

I was a little confused by the inclusion of T-Stops however?

Thanks,
Jay

[Steve]

whats a t stop...?

[SPtheALIEN]

The t-stop is light transmission. So, in essence, wide open, you'll get the light transmission of 5.6, I believe, but the depth of field of 2.8.

[Steve]

oh god...really....why ?

[SPtheALIEN]

oh god...really....why ?

For the best bokeh.

[SPtheALIEN]

The apodization element takes away some light from the edges (hence the lower overall light transmission), but the bokeh is so smooth (not nervous or unnatural).

[Steve]

it seems it used more for videography as changes f stops would be very noticable as switching a view around etc in the same local.....so the idea is to maintain the same amount of light across the seen.

[SPtheALIEN]

T-stop is very much a standard measurement for video. This lens, however, is a great lens for both still and video. I was so excited that they finally made one for FE and IT'S AUTOFOCUS!

[SPtheALIEN]

Note the bokeh quality. Most other lenses would have a little bit of a "nervous" bokeh.

[SPtheALIEN]

Here's another example of the bokeh quality.

- - - Updated - - -

The apodization element does that smooth, perfect circle bokeh quality.

[Steve]

it is very nice from that point of view

[SPtheALIEN]

I might be so bold as to say that bokeh is the reason you get this lens.

[Jay]

I might be so bold as to say that bokeh is the reason you get this lens.

Yes, I totally agree with that

[Steve]

I shoot landscapes and dont do much DOF stuff when taking them.....the bokeh is very nice agreed.

[antony]

It seems like the list of "fully compatible" of this SEL100F28GM is very limited. In short, only a6300, a6500, a7R II and a7S II and PXW-F55.

Saying that, other cameras can still use the lens.

[SPtheALIEN]

It arrived!

[SPtheALIEN]

[leuius]

whats a t stop...?

In short the F-stop is the geometric aperture (meaning the physical size of the lens/iris opening, compared to focal length) where the T-stop is the effective aperture (meaning the amount of light really transmitted through the lens).

T-stop is always a higher number (or equal but very rare) than F-stop.

Typically, the more glass in the lens, the larger the difference becomes because of reflections and light loss. In the case of the STF, there is a sort of "graduated density filter" (no effect in the center becoming more important towards the lens periphery) which blocks a portion of the light, hence the much higher 2-stop difference between T-stop and F-stop wide open. As you close down the iris, the "filter" (apodization element) is not blocking as much light and the T-stop to F-stop difference becomes less important.

Hope this helps...

Regards.

[leuius]

It arrived!

Nice pictures...