cokin vs. screw-in

[keithsnyder]

I am getting a wide-angle lens with an 82mm filter size. I am also

getting some Cokin P-size filters, mostly gradual-tones. I've seen

in other threads that the 82mm adapter might need some shaving to

keep it wide enough in the middle to avoid the edge of the lens. I

also notice in pics of the circ polarizer that it has a thick edge.

Would I be better served to get a screw-in circ pol, and add the

Cokin on top of that if I want to use any of the other filters?

[joseph_smith3]

Cokin has come out with a new P system that minimizes the problem with wider angle lenses. I would check this out. I have forgotten the width of the widest round filter that will fit the Cokin P system. You can always call Singh Ray and discuss the situation with them. They probably have had experience with your lens with a 82mm filter requirement. Joe Smith

[awindsor]

You don't say what the focal length of your wide-angle lens is and the filter diameter

is not always a helpful measure (especially since you don't say what format this is

for). I have the Canon 17-40. That has a 77mm filter thread but there is a generous

border between the filter thread and the front element.

 

The Cokin CPL seems to vignette quickly and is uncoated. It occupies a special slot

and the first slot. Any other filter will need to go in the second slot. If you stop the

lens down then you might be fine at 24mm but you would be safer at 28mm from my

experience. I don't own a doctored holder with only two slots (I have a 1-slot holder

without a polarizer slot and the usual Cokin 3-slot holder with a polarizer slot).

 

With my doctored holder I can successfully use a single filter at 20mm though I rarely

shoot wide-open where the fall off is worst. Typically I use a ND grad. This leaves no

room for a CC filter and so I often end up with blue shadows on sunny days. Since I

shoot to scan this is easily fixed in post processing.

 

Stacking filters on a very wide-angle lens is generally problematic and using a screw

in polarizer and a holder is an exercise in frustration.

 

I will shortly be getting a screw in polarizer since Puppy Face reports that a regular

(i.e. not slim-line) polarizer doesn't vignette on the 17-40. I had choked on the cost

of a slim-line polarizer.

[edgreene]

Cokin.

[awindsor]

I presume the previous was a vote for Cokin. I don't actually own any Cokin filters

except for their polarizer. I use Hi-Tech filters from Formatt. For graduated filters

screw-in filters are relatively pointless since the horizon is fixed.

[keithsnyder]

Sorry 'bout not mentioning the lens size. It is an 18-35mm Sigma for my Maxxum 5.