Center filter thread question

[Wally]

I recenly acquired a Heliopan center filter for my 75mm Caltar lens. It's got a 67mm inner ring size to fit the lens, and is 86mm on the other side.

I am looking at getting a Cokin 100mm (4") ND Grad set, and there are two kinds of filter ring adapters for 86mm filter sizes: Coarse thread (1mm) and medium thread (.75mm). They're about $50. each or I'd just buy both and figure it out. Does anyone know how to tell?


// Wally

[Bob Gentile]

IIRC, Heliopan filters are either .5 or .75mm. I don't believe they make a filter with a 1mm thread.

But Bob Saloman would know for sure.

[Bob Salomon]

86 x 1

[Wally]

86 x 1

Cokin has two screw-on X-Pro 100mm filter adapters for 86mm. The CX486A has a .75mm thread and the CX486B has a 1mm thread. Is this simply indicating the length of the threaded portion of the end that screws onto the lens? It sounds like I should be looking for the one with the shortest threads to ensure I don't vignette with my 75mm wide angle lens, right?

[Bob Salomon]

Cokin has two screw-on X-Pro 100mm filter adapters for 86mm. The CX486A has a .75mm thread and the CX486B has a 1mm thread. Is this simply indicating the length of the threaded portion of the end that screws onto the lens? It sounds like I should be looking for the one with the shortest threads to ensure I don't vignette with my 75mm wide angle lens, right?

It is the thread pitch. You simply want the standard 86mm thread. They will know what it is.

[Wally]

It is the thread pitch. You simply want the standard 86mm thread. They will know what it is.

Too bad I didn't understand what you meant when you replied "86 x 1". I assume now you were telling me 86mm with a 1mm thread pitch.

Well, B&H sales took me to what sounded like Jakarta. The first fellow I spoke with thought the catalog listing of two adapters of the same diameter was a mistake. I asked to speak to his supervisor. His supervisor assured me that it was a thickness thing, and since I was attaching this to a wide-angle lens, I wanted the thin one, so I should order the .75mm.

I couldn't see how a difference in thickness of just a quarter of a millimeter could be the difference between these two adapters, so I called Adorama, where someone that sounded quite confident said it was indeed a thread pitch, and he thought I needed the .75mm pitch.

Well, the 86mm Cokin X-PRO adapter with the .75mm thread pitch arrived, and surprise! It's the wrong one. Apparently my Heliopan 67/86mm center filter uses the 1mm-per-thread pitch, and now I wait for Adorama to answer my email requests for an RMA number and shipping tag.

I should have asked where you people shop and not relied on google to lead me to the photography store choices of the masses.

[Bob Salomon]

Too bad I didn't understand what you meant when you replied "86 x 1". I assume now you were telling me 86mm with a 1mm thread pitch.

Well, B&H sales took me to what sounded like Jakarta. The first fellow I spoke with thought the catalog listing of two adapters of the same diameter was a mistake. I asked to speak to his supervisor. His supervisor assured me that it was a thickness thing, and since I was attaching this to a wide-angle lens, I wanted the thin one, so I should order the .75mm.

I couldn't see how a difference in thickness of just a quarter of a millimeter could be the difference between these two adapters, so I called Adorama, where someone that sounded quite confident said it was indeed a thread pitch, and he thought I needed the .75mm pitch.

Well, the 86mm Cokin X-PRO adapter with the .75mm thread pitch arrived, and surprise! It's the wrong one. Apparently my Heliopan 67/86mm center filter uses the 1mm-per-thread pitch, and now I wait for Adorama to answer my email requests for an RMA number and shipping tag.

I should have asked where you people shop and not relied on google to lead me to the photography store choices of the masses.

I told you it was 86 x 1. That is the diameter of the threads (86) and the thread pitch (1) IT HAS NOTHING TO DO WITH THE THICKNESS OF THE FILTER. ORDER A HOLDER THAT YOU LIKE WITH MALE 86 X1 THREADS AND STOP ASKING OTHER questions to confuse the issue,

[Wally]

I told you it was 86 x 1. That is the diameter of the threads (86) and the thread pitch (1) IT HAS NOTHING TO DO WITH THE THICKNESS OF THE FILTER. ORDER A HOLDER THAT YOU LIKE WITH MALE 86 X1 THREADS AND STOP ASKING OTHER questions to confuse the issue,

Thanks for the advice. As I said, I'm sorry I didn't see that you were telling me the thread pitch I needed. It's my fault and I'll try not to do it again.

By the way, what other questions did I ask that confused the issue?