Sigma 300/2.8 DG prime

Hi all - I picked up a used Sigma 300/2.8 prime not long ago and have just received today the CPL ordered direct from Sigma Imaging UK, which was missing from the original deal.

Only thing is, I can't help but think they've tried to palm me off with the wrong item - the CPL is firstly as you'd expect a normal CPL to be, i.e. a rotating ring within a ring, polarising effect appear to be strong - only thing is, it's a nightmare to tighten into the little holder - there's nowhere to put your fingers to get a bit of purchase on the outer ring.

Second reason for concerns is that the code on the back of my pack is 8512692597 - which is the same code as the item listed as the bog standard CPL. There's no way of checking what the drop in APO part number is - the website isn't showing it, but the one marketed as the drop-in (and the one I bought) is about 10GBP less.

For marketed-as APO drop in - http://www.sigma-imaging-uk.com …for-apo--telephoto-lenses
For standard 46mm CPL - http://www.sigma-imaging-uk.com/filters/sigma-dg-circular-pl

Can any Sigma 300 prime owners tell me if theirs is the same?

The case doesn't say anything about being a drop-in filter or for APO teles. The ring on the filter itself says 'Sigma DG Wide Circular PL 46mm Japan'.

I just bought one brand new a few months ago too... Havent been bothered to check out the CPL, but when I get home from work I can let you know... I dont believe that the CPL has the extra ring though

Also, mine needed +17 MFA, you may want to fine tune yours if you notice soft images.

DanAnCan wrote in post #16186393
I just bought one brand new a few months ago too... Havent been bothered to check out the CPL, but when I get home from work I can let you know... I dont believe that the CPL has the extra ring though

Also, mine needed +17 MFA, you may want to fine tune yours if you notice soft images.

Thanks Dan - I get disappointed with these companies when these sorts of things happen. I did get the UV clear drop in which has a completely different ring design. It's much deeper and the ring thicker.

I wouldn't be so bothered, but you can't tell if the CPL or the thread is what's rotating, and I read that these drop in filters are part of their optical design, so to send me one which isn't designed to sit in line with the other elements is annoying.

It'd be good to get a couple of users describing their CPLs to make sure I've got the wrong one.

I'm out of luck on MFA - 5Dc body. From what I read, MFA adjustments are not always accurate throughout the focus range. I'll see how it behaves this weekend.

Yes, the lens needs to have a filter in place, that's why they supply a clear & polarizing filter..

im not too sure on how the design works, I just know that it does need one in place..

hopefully yours wont need MFA, and yes you're correct about the accuracy throughout the range..

specifically mine was ~+15 around the MFD and ~+20 around infinity, having it at +17 gives me sharp images throughout the range...

+/- 2 or 3 isn't noticeable, but +17 definitely was.. there is no PERFECT lens!

DanAnCan wrote in post #16186858
Yes, the lens needs to have a filter in place, that's why they supply a clear & polarizing filter..

im not too sure on how the design works, I just know that it does need one in place..

hopefully yours wont need MFA, and yes you're correct about the accuracy throughout the range..

specifically mine was ~+15 around the MFD and ~+20 around infinity, having it at +17 gives me sharp images throughout the range...

+/- 2 or 3 isn't noticeable, but +17 definitely was.. there is no PERFECT lens!

I'll have to think about a 5D2! Did you manage to take a look at the design of your CPL? Thanks.

Yep. The filters you posted links to appear to be the same as the ones that I have. See pics below.

The first pic is the "normal" filter that the lens had dropped in when I bought it.

DanAnCan wrote in post #16187529
The first pic is the "normal" filter that the lens had dropped in when I bought it.

Great - just to clarify, that CPL glass is a single ring that, if used outside on the front of a lens with 46mm thread would require you to actually loosen the filter in order to rotate it?

I'll see what Sigma say today.

Thanks for your help Dan - they sent me the wrong one, admitted the fault and offered to pick up the wrong one while dropping off the new one within 24hrs.

Can't say fairer than that!

Glad you got everything sorted out!