Grad ND Resin Vs Glass (holder, ring or rectangle)

[HorvathMF]

I am looking at getting a Graduated ND Filter, but I have noticed that some are glass and others are resin. I was searching on the internet, and from what I gather, with a normal focal length lens there is little change in quality, but with a longer length lens there is significant degration of quality with a resin filter, also that the resin scratch very easily. How true is this?

If there is significant degration in quality with a resin filter, what companies make reasonable glass Graduated ND filters?

Also saw that there are ring Graduated ND filters, but for the life of me, I can't figure out why you would want that when you can have more control with a square, or rectangle piece of glass. I feel that with the rectangle you can move it up and down according to the scene, but with a ring filter you will have to recompose your shot to place the gradation where you would like it. What am I missing here?

Last thing, with a rectangle graduated ND Filter, most people on the internet are talking about holding them while taking the exposure, what are the benefits/drawbacks to this method compared to using a Filter holder?

Thanks so much in advance, this community is invaluable, and has so much knowledge!

[dsphotog]

I use Singh-Ray & Cokin grad filters, and see no difference in sharpness in the resulting images.
A popular technique is to keep the handheld filter moving during a long exposure, to minimize any chance of the line showing.

[Sevo]

I don't know whether there are any glass-only grad filters about. I have a grey glass wedge somewhere, but its prismatic nature makes it useless on a lens, it is intended for densitometer calibration.

That is, all glass grad filters I am aware of are are glass cemented gelatin. Resin has lower refraction and better planarity than such a dual glass plate sandwich, making it optically less troublesome, but it is more subject to scratching or warping. And other than the (effectively zero strength) layer of dyed gelatin in a glass filter, resin is often dyed in the mass (and resin plates tend to be stronger than glass for rigidities' sake), so that the edge rays travel through a noticeably longer distance of filter - i.e. resin filters can vignette on wide angles.

[lenser]

I've been using the same Cokins since the late 70's (?) or thereabouts, with no scratches due to careful handling and storage. The only one I've ever had to replace was a Polarizer (which is glass) that I dropped on some pavement and it shattered.

I've seen no issues for image quality with any of the lenses I've used them on.....from very WA to mid range telephoto. They have been used on everything from 35mm to 8x10 with seemingly equal success.

The only one of the set that is not square is the Polarizer. All of the several others in my kit are rectangular including the three (various colors) of graduated ND's.

[Ivan J. Eberle]

Tiffen makes glass grad NDs to fit the Cokin P filter frames. B+H and Adorama stock them. They're in the ballpark of what the Singh Ray resin filters cost and yes, they're not as prone to scratches. But they're not unbreakable (Took several spills with the Tiffen in it's soft padded case inside a hip pack along with my medium format while CC Skiing before it broke).

Bear in mind that the situations where you'll need a graduated ND pretty much all involve color transparency films. You'll need several different ones, abrupt to soft transition in various strengths. Now, I like a beautiful transparency as much as the next guy, but at some point it became easier to carry color neg films too and choose film type rather than carrying and choosing among multiple ND grad filters. Especially since I'm scanning.

[Boinzo]

I have worked through a conga-line of ND filters. To me it's not so much a question of glass vs resin. More one of which resin filters to get.

Glass NDs and GNDs are available (from Lee for example) but are extremely expensive. And fragile. As others have mentioned it is unlikely you'll see any difference in sharpness. To me it's hard to think of a circumstance where I would want to combine a GND and a long focal length anyway. I guess they exist but it's not something within my experience. I also don't want to be crawling around on half-dark rocks near the ocean with a piece of glass in my hand.

I started with Cokin's P series filters on my little camera. These were fine as it goes. But it depends a lot on what you are shooting. I do mostly seascapes at sunrise and this can require some substantial stopping power. I found very quickly that combining a Cokin resin filter with any other ND filter (Cokin or otherwise) results in an intense magenta cast across the entire image. This has been the experience of many others as well. If you are shooting B+W this may not matter. It did to me.

I also tried Singh-Ray's reverse ND grad. A great filter but can also cast in combination with other filters. I believe some of their other filters are very good.

I now use Lee and some Hitech ND filters. These are resin. And very very good. (I have no association with Lee Filters - just a happy user).

I use a filter holder rather than attempt to hold a filter manually. This is because I commonly combine filters and it means I can get precise control of the GND's "horizon". I also use ultra wide lenses and it can be hard to keep your thumb out of the frame! It can also be hard to hand-hold if your exposure is very long - like minutes. I will also help in avoiding flare - especially if you shoot into the sun. If I need a gentle transition in the effect - I use a soft GND.

My setup is a holder with 3 slots that has a 105mm CIR polarizer in front and a lens hood as part of the holder. It was stupidly expensive but I love it. It simply clips onto a mounting ring on the front of each of my lenses.

Yes. Resin filters scratch easily. But lenses break easy when you drop 'em too. If you are careful and use a dedicated velvet pouch and clean them carefully after every outing they'll last for ages.

I would suggest looking for the best filters you can afford. After thinking about you plan on shooting with them. I have wasted a lot of money on sub-standard or disappointing filters that I no longer use. There is a touch of "a poor man pays twice" about filters for me....

You will likely want to be sitting down when you see the prices ....

[Eric James]

I don't know whether there are any glass-only grad filters about. ...

Schneider makes glass grads; I believe they are marketed to the motion picture industry. They go for roughly 3X the Lee price.

[HorvathMF]

Thanks for all the information guys, I'll be looking into the ones I can afford this weekend, thank god for payday!

[Asher Kelman]

I have worked through a conga-line of ND filters. To me it's not so much a question of glass vs resin. More one of which resin filters to get.....

I started with Cokin's P series filters on my little camera. These were fine as it goes. ....I found very quickly that combining a Cokin resin filter with any other ND filter (Cokin or otherwise) results in an intense magenta cast across the entire image.

That's an important warning. Thanks!

also tried Singh-Ray's reverse ND grad. A great filter but can also cast in combination with other filters. I believe some of their other filters are very good.

Another good warning! Again, thanks for sharing.

I now use Lee and some Hitech ND filters. These are resin. And very very good. (I have no association with Lee Filters - just a happy user).

I use a filter holder rather than attempt to hold a filter manually. This is because I commonly combine filters and it means I can get precise control of the GND's "horizon". I also use ultra wide lenses and it can be hard to keep your thumb out of the frame! It can also be hard to hand-hold if your exposure is very long - like minutes. I will also help in avoiding flare - especially if you shoot into the sun. If I need a gentle transition in the effect - I use a soft GND.

My setup is a holder with 3 slots that has a 105mm CIR polarizer in front and a lens hood as part of the holder. It was stupidly expensive but I love it. It simply clips onto a mounting ring on the front of each of my lenses.

What would you use with the largest diameter lenses? I was thinking of using the one designed for the extreme wide angle 35mm lenses from Lee that hold 5" Lee filters. Is that what you'd suggest, or is there another solution?

Asher

[Ivan J. Eberle]

The largest diameter wide-angle lenses are also going to require a spendy center graduated filter when used with transparency film. I think these cost more than what I spent for my Nikon SW90 f/8.

Adding up the cost of all these filters caused me a recalibrate the mission. Color neg film in less than perfect light solves having to buy a set of grad ND filters, and the center filter need is resolved in Photoshop. Probably saved me enough money to buy another used lens or two, and a scanner.