Vignetting with Cokin filter holder

[will king]

Got a 20D with 17-85mm lens. I just used the Cokin P series filter

holder with a grad ND 2 stop filter. The first thing I noticed was a

vignetting effect at the 2 bottom corners. I'm not even sure if I

want to call it vignetting. It displays the 2 bottom corners of the

filter holder at wide angles: 17mm to about 20mm. Is there anything I

can do to avoid this issue? I want to continue shooting at wide

angles but don't want to have to crop off 10% of the bottom. In

addition, I'm getting the Canon 10-22mm superwide angle lens. Of

course I'll probably have to get another filter holder for that. Is

there another type or brand any one can suggest that does not have

this issue? On a side note, are Singh Ray filters worth spending that

much more. There's a huge price difference between Singh Ray grad NDs

and Cokin grad NDs. Just wondering if it's worth spending the extra

$. Thanks in advance.

[William Kahn]

Is the filter holder seated all the way down on the ring? I have the 18-55mm lens, and I don't see any vignetting at all at 18mm, even with a two-segment hood attached.

[will king]

I'm pretty sure it is. I can try it again when I get home tonight. Do you have the Cokin P series holder?

[abrepsom1]

Hello Will,

 

Cokin does offer a wide angle filter holder for the P series. It is basically the same as if you just cut off the two outer slots of the standard filter holder.

Otherwise, you'd have to get the X-series, which are very large and wouldn't cause any vignetting on your 17 mm lens.

Another (expensive) alternative would be the LEE filters. They are larger than the P-series. LEE does also have special wide angle rings. Check at www.leefilters.com

 

As for the quality of the ND grads, it has to be said that the Cokin ones are not really neutral, as the have a slight reddish/pink color cast, but with digital, this might not be an issue. There are very good (and reasonably priced) ND grads form HiTech fitting the Cokin P-series holder. Check at www.bhphotovideo.com

 

Kind regards

[will king]

Thanks Ander. I kind of noticed a blue-grayish tint to the Cokin grad ND. Anyone have anythoughs on Sing Ray NDs?

[William Kahn]

Will, I do have the P-series holder. Try several different shots at different focal lengths, and see if there's a difference. If you see the vignetting in the image but not in the viewfinder, you might be experiencing some of the "normal" wide-angle vignetting of digital wide-angle lenses at minimum FL.

[will king]

I see it in the view finder too, and it's only at wide angles, 17-20mm. So do you ever get this at 17mm?

[William Kahn]

My lens only goes down to 18mm....

[will king]

does it vignette at 18mm with the Colkin?

[William Kahn]

OK, I just tried it again in better light (sun just came out): With the lens hood on (two snap-together segments) I get slight vignetting at the corners. With the lens hood off, no vignetting at all.

[Ken Katz]

If you check the PN archives, it has been common practice to saw off the last 2 slots on a Cokin P holder, so it will not vignette with wide WA lenses (hack saw works fine).

 

HiTech split grads are much cheaper than Singh Ray and seem to work fine.

[will king]

Kenneth, when were you before I order the Colkin XP series filter holder for $57. LOL. Is there a link that gives specifici instructions on how to do this? Thanks BTW.

[awindsor]

The standard Cokin P holder has a slot for a polarizer. You can find a plastic holder from HiTech without a polarizer slot. This can be modified to be even slighter than the Cokin P.

 

I use the HiTech grads. I haven't noticed any colour cast but since going digital I haven't been using them as much.

[Ken Katz]

"Specific instructions"

 

The thing is made of plastic, and has 4 filter slots. So just cut off 2 slots (I used a hack saw). The P holder is real cheap, so if you mess up, you have not lost much.

[nicholasprice]

Will, Vignetting is often inevitable with undedicated attatchments to ultra wide angle

lenses. If you still have the problem, you could attach the filter directly to the lens casing

(assuming that the glass of the lens doesn't protrude beyond the casing) with 4 small

pieces of Blue-Tack adhesive. This works very well as a solution, but may slow down your

photography - but this is fine for tripod mounted landscape work (slowing down your

photography here is probably advantageous!)

 

...another draw back is the greasy mark left on the polyurathane filter, so buy lots of

disposable lens wipes!

 

Regards, Nick.

[mark u]

I strongly suspect you didn't mount the holder correctly. P series filters are designed for use with lenses of up to 82mm filter diameter, and the 17-85 is only 67mm. Moreover, the 17mm crop angle of view is not that challenging. Suspicions are redoubled by the fact that you only observed vignetting in 2 corners, rather than all 4.

[will king]

Mark, that maybe the case. I will try it again, and if it still happens, I will post a sample photo. Thanks.

[jorge_garcia1]

I have been investigating how to use cheap (or at least not so expensive) ND grads on the 10-22mm, my conclusion -at this moment- is to use an inverted Z Pro filter holder.

Instead of cutting off two guides you can use it reversed. You can also use 4mm filters.

Look at www.cokin.fr/cokin-data/news-product/PDF/Z-PRO-site.pdf

[will king]

Thanks all who responded to this thread. It turns out that it was user error. I had a 8 point star filter that was not pushed down all the way that was causing the issue. It's fixed now.

[yinkamd]

Will,

Have you considered the Sigma 10-20? Its supposed to be pretty good, probably better than the Canon. I am hoping to get one soon.

 

Yinka

[will king]

I heard otherwise. I have heard the Canon is the better lens, besides I already ordered it.