Ektar 203 filter thread size..

[Brooklyn45]

I have a newly aquired Ektar 203 in a compur shutter, there is a thread for a filter. Anyone happen to know what size that would be..

Thanks all

[John Kasaian]

Mine dosen't have threads but uses a slip on series filter adapter (a Series VII, IIRC)

[Jim Fitzgerald]

When I had mine I think it was 52mm. Great lens.

[Brooklyn45]

No Jim, the outside diameter is about 38mm.. takes a 38 slip on series VI filter.. but I want to see if someone knows the internal thread size..

[IanG]

Kodak state they take a Series VI slip on filter also 33mm which seems to be the internal thread

It may also depends which version US/UK.

Ian

[Brooklyn45]

That can't be right unless its referring to the mount 370 lenses sold a lot in the UK. The one I have measures 35.69 mm inside. I wonder if that means a 36mm thread..

[IanG]

That 33mm was from a 1945 US Kodak databook, OK it was for the 203mm f7.7 Anastigmat (earlier un-coated version), however I've just checked a later 4th Edition Dataguide and the Ektar is identical specification but coated.

While mine's a Mount 370 UK made version (so non Supermatic - Epsilon, Prontor SVS, Compur #0 fully compatible) I'd agree at firts glance it appears to be closer to 36mm inside but theres a chamfer on the lip so the thread size does seem to be 33mm and I cut some card to33m and it's a tight fit across the internal diameter.

Ian

[Brooklyn45]

Well as I thought yours is a Mount 370. That one fits in a 0 shutter and is v.small. They made I think three different variations. The older ones that fit in a supermatic. (which have no threads) Then the newer ones like mine that fit in a compur #1 and those more common in Europe the Mount 370 that fits a #0 shutter often found in prontor or epsilon shutters. There is no way a 33 mm filter fits this lens as I said before it measures 35.69mm on the inside.

Can anybody corroborate that a 36mm filter will fit ??

[IanG]

A quick Google search shows the US made 203mm Ektar in a different front and presumably rear barrel to adapt them to a Compur 1 shutter, so you're right that there's two US versions, the retaining ring for the front cell seems to be the same size. The filter size is definitely wider.

Ian

[Rick Keller]

I realize this is an old thread, but I am interested to know if a 36mm filter did indeed fit. I just acquired a Kodak Ektar 203mm f/7.7 in a Compur shutter, too, and I am looking for an appropriate screw-in step-up ring ...