Lens Filter Thread size

[AuditorOne]

I have two lenses with adequate coverage to work with my 8x10 camera. Both are working well with the exception of one small problem. I cannot figure out what the filter thread size is. I thought I had it worked out for the one, and bought a nice, metal lens shade, but it does not fit. Now I am a little uncertain and do not want to spend anymore money on either lens until I have some better information.

The first lens is a very nice Calumet Caltar-S II 9.5 inch f5.6. It has a large front ring and I thought it was an 87mm, but that turned out to be incorrect. Can someone point me in the right direction on this one.

The second one is a much older lens, at least I believe so. It is an Ilex Paragon f6.3 12 inch Series S in an Acme #4 shutter. So far I like this lens quite well but, again, I have no idea what the filter thread is. I tried my 62mm adaptor, and that was too big. Then I tried the 58mm adaptor, but that was too small. I do not have anything with a 60mm thread to test with. I can pick up another adaptor with a 60mm thread (this will be my only lens with that filter size), but I hate to spend the money for something I have no other use for. Additionally, as it is an older lens, I wonder whether it may be different entirely from the 60mm size being sold today.

Just to clarify here, I do primarily use step up and step down adaptors for threaded filters, and have never bought any of the Cokin gel filters so far. I would like to avoid that if I can. I have nothing against the Cokin system, but to go that way means additional purchases I would rather avoid.

Thanks very much for any help you are able to provide.

[John Koehrer]

The Paragon is likely to be US size and would use a slip on adapter. These*were more common at that time. A simple measurement of the barrel will give the adapter size.

You didn't mention whether the 87 was large or small. At least it should be a metric thread. If you don't have a caliper, measure the outer diameter of the barrel and subtract 3mm from it. Since filters are only made in a relatively few sizes it gives a very good way of judging the size. IE: outer barrel dia=~85mm, deduct 3mm filter should be 82mm.

The Caltar is either Rodenstock of Schneider and the information will be on their respective sites.

[fecaleagle]

Somebody who owns one can correct me if I'm wrong, but I believe the Caltar-S II is a re-branded Schneider Symmar-S, whose data sheet indicates that the filter size is 86mm x 1mm. Was the 87mm close, and did the thread pitch match?

Edit: the data sheet!

[AuditorOne]

The 87mm hood is just a tiny bit too large to fit so 86mm does make sense. I am not sure of the thread pitch as I don't have a thread gauge but the hood threads look a bit coarser then the lens threads. Of course I quit trying to judge those things by eye long ago unless there was a big difference in pitch, and there is not.

As for the Paragon I never considered a slip on, but it might work as the barrel is straight. I do have a micrometer and the outer barrel measures 63.15mm. The inside measures just a hair less than 59mm so it would seem that a 60mm is a good bet but I will see whether I can find a slip on that big. I do have a slip on for my Crown Graphic and for a couple of my folders and they are nowhere near that big.

The data sheet was a great assistance, thanks. I am relatively new to the LF game so I am not absolutely certain what all that means, but I will learn.

[Leigh]

The 87mm hood is just a tiny bit too large to fit so 86mm does make sense. I am not sure of the thread pitch...

86mm is a standard thread for filters and such; 87mm is not. I don't know where you would have found such.

The pitch in these larger sizes would be 1mm. In smaller diameters like 67mm the pitch is 0.75mm.
I know of no sizes in which both pitches are offered, so don't be concerned about it.

The datasheet shows a filter thread ("Accessory Thread") of M86x1, indicating an 86mm thread with a 1mm pitch.

- Leigh

[AuditorOne]

86mm is a standard thread for filters and such; 87mm is not. I don't know where you would have found such.

Where else? http://www.ebay.com/itm/251073129296...9#ht_648wt_690

The pitch in these larger sizes would be 1mm. In smaller diameters like 67mm the pitch is 0.75mm.
I know of no sizes in which both pitches are offered, so don't be concerned about it.

The datasheet shows a filter thread ("Accessory Thread") of M86x1, indicating an 86mm thread with a 1mm pitch.

- Leigh

Great to hear Leigh. I will start looking around and see what can be found.