135 STF first take (includes several large images)

My STF arrived a few days ago. First impressions: it's a substantial chunk of glass, I need some more practice with it, and the bokeh with this lens is simply outstanding.

I've managed to take a few shots to compare the STF to other lenses. For all shots:

- 7D mounted on a tripod
- 2 second self timer
- AS off
- Auto white balance
- Aperture mode for non-STF
- STF aperture ring used to set aperture
- JPEs straight from the camera, Sharp+1, contrast-1. Image layouts created using PWP, but no other post processing.

Here's a comparison between the STF and the original 135/2.8, both wide open, with the focal point on the central small white flower in the foreground:



Here’s a comparison with the focal point on the rock several feet behind the flower.



In comparison to the STF, the edges to the OOF highlights are noticeable with the Orig 135 and there is more noticeable CA, although you need to pixel peep to see it. It’s also clear from the second comparison that the STF is sharper wide-open.

Here’s a comparison between the STF and the original 85/1.4.   I kept the camera location the same, so angle of view is different between the two. I’m not really sure whether this is an appropriate way to compare lenses of different focal lengths, but my judgements are subjective and non-scientific, so it seems as good a way as any.


As with the orig 135, the 85 shows much more obvious edges to the OOF highlights and it also shows more CA around the white flowers, even at 2.8.

Here’s a comparison with the 80-200 HS G at 135mm, f2.8.



Same results in comparing OOF areas, but the 80-200 shows slightly better control over CA.

I also did some comparisons with the lens stopped down. Here are four shots of the same scene with progressively smaller apertures.



As the STF is stopped down, the edges to OOF areas become more pronounced, and the circular shape of OOF highlights becomes more apparent. In the second image, I noted the aperture setting as “T5.0”. This is an approximate value because the aperture ring offers continuous adjustment between T4.5 and T6.7, and I set it approximately halfway between 4.5 and 5.6.   

Finally, here is a comparison of the STF and the original 135, stopped down to T6.7 and 5.6, respectively. The physical aperture size appears to be similar, but not exactly the same size, with the lenses set this way.



With the STF stopped down, there’s a small OOF point of light above the left flower that is more noticeable and not much different in appearance than the Orig 135 image, but the rest of the OOF background is still smoother with the STF.


For me, this lens is a keeper. The "smooth transition" really works, even stopped down; where other lenses show edges to OOF highlights, this one does not. If you're a bokeh fan and like working with this focal length, this lens is for you. Review to be posted soon.


Edited by wblc - 20 December 2006 at 08:25

Never seen a so remarkable comparison. This lens is evev better than its reputation.

Excellent review

Regards

WOW .. thank you for this comparision.
I hardly wait some new feedbacks about this unique piece of glass.
Thanks for sharing


p.s.
May i ask you if you are interested in a dedicated webpage with this contest?

congrats wblc~

watch out -its addictive:)

Funny how the arrival of the STF suddenly means that 'faults' are found in the 85 1.4 bokeh ;)

btw Kiklop and wblc:

If you want I can send you the following highlight samples to add to wblc's comparison shots (as eg tag along with his dedicated page)

______________

highlight example:
STF


135 2.8


Edited by Kiklop - 17 January 2007 at 18:32

Thank you Bernard !!
You are invited to share as many information about this fantastic lens as you wish and i will then use this in a dedicated webpage.
Thank you !

PeterP wrote: Sorry to be so dim - but I have absolutly no idea what STF means. could someone give us a quick idiots guide?

Its an AF mount but MF only lens with a nomimal f2.8 aperture which is conditioned by the use of an "apodisation" filter that presents an effective max aperture of f4.5 to the sensor/film.
STF means Smooth Trans Focus (the on-lens appelation) or Smooth Transition Focus.
A good explanation/review here.