Filter size help

[Rick A]

I have a Calumet Caltar type S 150/5.6 and I can't find any info on filter diameter, and yes, I looked through Camera Eccentric for both Calumet and Schneider catalogs to no avail. Thank you in advance for the assistance.

[Steve Goldstein]

I think the Caltar Type-S is a rebadged Symmar-S, in which case the filter would be 58mm for the 150.

I'm a little confused, though - if you have the lens, why can't you simply measure it? The difference between 55mm and 58mm (or between 58mm and 60mm) is enough that you're unlikely to make an error.

[Rick A]

I don't have a caliper and a ruler is not very accurate, especially in inches.

[Bob Salomon]

What is the number on the inside of the front cap? That is the outside diameter of the lens. Subtract 2 to 3mm and you will have a common filter size. That is the size filter that you need. So if the number in the cap is 60 your lens takes 58mm filters.

[David Karp]

So long as the front cap is of the slip over type and not a replacement snap cap.

[Bob Salomon]

So long as the front cap is of the slip over type and not a replacement snap cap.

If it is a snap cap then if it is numbered it is the filter size.

[Rick A]

It's a Schneider plastic slip over cap, but no number inside. I'll order 58mm filters for it then. My thanks to all who replied.

[Professional]

I have a metal ruler that is in mm/cm and inches/foot, accurate, i use most of the time for things up to 30cm as the limit of this ruler, if i had your lens then i can measure it for you, i can do by facing it to most of my lenses or use my lenses filter thread numbered caps and see which one is matching it.

Try to find a good ruler, and measure it for me in any unit and convert it to the unit you need for filters, say you measure it in inches then convert it to cm or mm, then you will know approximately which filter size you need, i don't think it will give you a huge mistake.

[Professional]

And from this link, yes, it sounds yours is 58mm

http://www.bhphotovideo.com/c/product/800676432-USE/Caltar_150mm_f_5_6_Caltar_II_S.html