Sigma 12-24mm EX - Arrived...

[iwatkins]

Hi All,

Been waiting for this lens for a few weeks and got the call this morning.

Anyway, dropped into town at lunchtime and picked it up. While I was there I took a few quick shots from the roof of the car park I had parked at.

I took one shot with my Sigma 17-35 at 17mm and then with the Sigma 12-24 at 12mm. I've overlayed the 17mm shot on top of the 12mm below for comparison.

First impressions are again, a nice solid EX lens (all black case rather than green ?), manual focus even when set to AF. The motor is very very quiet but not very fast (not bothered really, this is my new landscape lens).

Full time hood on it. The lens cap fits to a cylinder that then sits on the front of the lens (if that makes sense). With the cylinder on but the lens cap removed you do get an 82mm filter thread. How much vignetting is going to happen using this, well, I don't know yet. The lens does have a rear gelatin holder.

Cheers

Ian


Sigma 17-35 (at 17mm) overlayed on Sigma 12-24 (at 12mm)

http://www.netcomuk.co.uk/~iwatkins/Gallery/sigma_comp.jpg

[chris maddock]

Hi All,


Full time hood on it. The lens cap fits to a cylinder that then sits on the front of the lens (if that makes sense). With the cylinder on but the lens cap removed you do get an 82mm filter thread. How much vignetting is going to happen using this, well, I don't know yet. The lens does have a rear gelatin holder.



It'll vignette - that sleeve has only to be fractionally out of place and it appears in the corners.

KRs
Chris

[iwatkins]

It'll vignette - that sleeve has only to be fractionally out of place and it appears in the corners.

KRs
Chris

Hi Chris,

Is that from direct experience ? I ask as I was going to try a "thin" cir. polariser on the front, once I find one to 'borrow'.

Cheers

Ian

[CyberDyneSystems]

Wow,. 12mm! :shock: That's WIDE Baby!
8)
It may not Vignette with the 10D and it's smaller CMOS size. The 12-24 will work on a 35mm as well.

The Built in Hood/ring/lens cap deal sounds identical to that found on the 15-30mm Sigma EX.

It was my understanding (although I did not try it myself) that the Filter on the ring thing did NOT vignette on the 10D but does on full frame sensors and 35mm film....

just put the ring on and see if it Vignettes on it's own. If it doesn't,. then pull it out an 1/8th of an inch or so,. see how far you can bring it forward before you see it in the corners,. if that distance is more than the thickness of a filter,. your all set!

[chris maddock]

It'll vignette - that sleeve has only to be fractionally out of place and it appears in the corners.

KRs
Chris

Hi Chris,

Is that from direct experience ? I ask as I was going to try a "thin" cir. polariser on the front, once I find one to 'borrow'.

Ian

Yes it is - that's why I was so categoric ;-)

If the sleeve/lens cap holder is more than about 0.5mm forward of it's fully home position it starts to show in the corners - and that is on a 10D.
Any screwin filter will eat up a small amount of the inside diameter of the ring, no matter how thin, reducing that diameter and causing it to start encroaching on the corners.

I have been experimenting with getting filters to fit and not vignette, my current findings are;

1) Polariser - a Cokin P-series (or Kood equivalent, like I use) can have about 0.5-1mm trimmed off all round and will fit "inside" the petal hood. I made a 14mm long sleeve to fit inside the hood with four bent brass brackets (fitting at the deepest part of the petal cutouts) to retain the polariser. That gets the filter far enough back that it will not vignette on a 1.6x crop camera.

2) ND Grads - Cokin P-series are just large enough provided they are fitted immediately (0.5mm or so) in front of the petal hood. I made a ring to slip outside the lens (imitating the slipon hood) lined with felt (actually, the soft half of a velcro strip) and with the front slots of a Cokin P-series holder fixed on the front. Even then, the Cokin offcuts had to be filed back in the centres to avoid vignetting if the holder was turned so that the middle of the slots matched up with the corners of the frame.

I have photos of the Mk1 versons of these - email me if you want to see them (356Kb zipped). Not sure if the lack of an email button against my last post is because I'm looking at it myself or what - if it doesn't show up I'm chris@maddock.org.uk

On a full-frame camera, gawd knows. I reckon Lee 100mm filters might do, if not it's Cokin X-Pro - mega-bucks :-(

KRs
Chris

[iwatkins]

Thanks Chris, you have mail. 8)

Cheers

Ian

[chris maddock]

Thanks Chris, you have mail. 8)
Cheers
Ian

You're welcome - so do you.

KRs
Chris