ND/GND Filters... 85mm or 100mm?

Looking at some GND filters, mostly Hitech branded ones, since Cokin apparently has colour issues and Lees are horrifically expensive...

The question I have is whether 85mm x 105mm filters are enough or should I spring for the 100mm x 135mm ones? The main reason I ask is I'm not sure if the smaller ones will be enough on my Tokina 12-24mm...:confused:

looking on with interest and rather recanting from previous opinion that it could be done fine in PP - having torn out much hair trying to get exposures right in Lake District (English) between southward sky and heavily shaded valleys nearer to. Basically impossible ( see my pbase galleries /greatgable & /dalehead )so may get a NDG if modest price solution springs up. (and 1 unit can be converter mounted on 58 and 77 dia lenses). I have a catalogue from an outfit called SRB (srbfilm.co.uk) but don't know how good/bad non-famous stuff can be.

Hi James,

If you're using wide-angle lenses then you need the 100mm x (typically) 150mm variety, or you risk severe vignetting from the holder - especially when stacking.

I'm not familiar with Hitech brand - I use Singh-Ray brand in a Lee holder myself.

Quote:

---

Originally Posted by crisscross

... may get a NDG if modest price solution springs up. (and 1 unit can be converter mounted on 58 and 77 dia lenses).

---

Hi Chris,

The usual approach is to use a standardised holder, such as the Lee foundation kit, and then adapt it to the particular lens diameter using the appropriate adaptor ring; eg. 58mm and 77mm.

The dilemma I have is that I've been offered a set of 85mm Hitech GNDs for a rather reasonable price. However I'm getting confusing signals from the internet about whether they will vignette or not. Might just go for it and see, apparently if I modify the holder slightly it'll be fine... =/

If cost wasn't an issue a Lee DSLR Starter System will be in the post to me right now, but I can't justify £150 for occasional use...

Quote:

---

Originally Posted by Mossy

The dilemma I have is that I've been offered a set of 85mm Hitech GNDs for a rather reasonable price. However I'm getting confusing signals from the internet about whether they will vignette or not.

---

On a 12-24mm lens - wide open - I'd be very surprised if they DIDN'T vignette ... but if you hand hold them and stop down a bit then you'll probably be OK. (or use the rubber-band / duct tape "technique").

Let us know how you get on eh?

Oh my gosh!.......if I would have read your recommendation, I just ordered a few days ago some Singh-Ray GND for a Cokin P holder :(

Quote:

---

Originally Posted by Daniel Salazar

Oh my gosh!.......if I would have read your recommendation, I just ordered a few days ago some Singh-Ray GND for a Cokin P holder :(

---

Hi Daniel,

Just give them a call and tell them you'd like to upgrade - I'm sure it wouldn't be a problem. I find that even with my 100mm wide filters I still have to be careful when trying to shoot wide with stacked filters.

Let me know how you get on?

PS: Even if they've shipped you could probably still exchange them if they haven't been opened (by prior arrangement).

Yeah, probably a good idea to get it changed. I tried a Cokin P holder today without filters and could see the the filter holder when at about 14mm. Guess I'll have to bite the bullet and get a set of 100mm...

Quote:

---

Originally Posted by Mossy

Yeah, probably a good idea to get it changed. I tried a Cokin P holder today without filters and could see the the filter holder when at about 14mm. Guess I'll have to bite the bullet and get a set of 100mm...

---

Do it right ... only do it once :)

Besides, "P" size filters are a lot more expensive (if you can work that one out!)

thanks Colin, unfortunately I already used them once, now it seems that I would have to hold the holder with some rubber band.

Just one question, using a camera that is not full format and using wide lenses that are not wider than 16 mm, do you think they holder will produce some vignetting?

I was also planing to buy a Gold & Blue Polarizer from Singh-Ray, however I do not know what is better, to get a 77mm ring mount or a Cokin P mount?

Quote:

---

Originally Posted by Daniel Salazar

thanks Colin, unfortunately I already used them once, now it seems that I would have to hold the holder with some rubber band.

---

Just be careful not to scratch them if you're going to use the rubberband technique.

Quote:

---

Just one question, using a camera that is not full format and using wide lenses that are not wider than 16 mm, do you think they holder will produce some vignetting?

---

Hard to say - chances are you'll get away with it.

Quote:

---

I was also planing to buy a Gold & Blue Polarizer from Singh-Ray, however I do not know what is better, to get a 77mm ring mount or a Cokin P mount?

---

They don't make one for a P mount - so that's an easy one to answer :)

Thanks to all you guys for the posts. I've been considering both the Cokin P system and the Singh-Ray neutral density varieties.

Joe

Quote:

---

Originally Posted by joec

Thanks to all you guys for the posts. I've been considering both the Cokin P system and the Singh-Ray neutral density varieties.

Joe

---

Hi Joe,

For what it's worth, I'd suggest considering the Lee holder system over the Cokin (better quality).

They don't make one for a P mount - so that's an easy one to answer :)[/QUOTE]

Hi Colin, might be that before they didn't have them, however now there is also for the Cokin P mount, however I think that better to order a ring mount one, but the question is thin ring or not?

http://www.singh-ray.com/goldnblue.html

...and for the ones that would like to know the rubber band "technique" here I'm posting a picture provided by Kevin McNeal on the Singh-Ray blog

http://2.bp.blogspot.com/_9OLTJDwSRt...ilterSetup.jpg

Quote:

---

Originally Posted by Daniel Salazar

Hi Colin, might be that before they didn't have them, however now there is also for the Cokin P mount, however I think that better to order a ring mount one, but the question is thin ring or not?

---

Hi Daniel,

Not sure where you're seeing P-Mount - but all I'm seeing are ring mounts, with the sole Cokin offering being a sprocket ring mount.

Update: I think we're talking about the sprocket variety - didn't realise the the Cokin mount had that facility (I tend to think of Cokin P mounts as being just for the sliding filters). I think I'd be inclined to go with the screw-in variety - you can always hand-hold a GND in front if you have to, whereas with the sprocket mount you're likely to get bad vignetting with WA lenses from all the other slots. (some of the combinations I've tried with the 100mm versions stacked on a 82mm Vari-ND result in outright obstruction at anything under about 25mm).

If anyone is interested, Darwin Wiggett has posted a very relevant article on this very topic on the Singh-Ray blog - just scroll down to the April 21st entry.