6 stops ND for Yashica TLR

Hi folks,
I plan to shoot some city pictures with my TLR, but I want to use quite long exposure (10-20) seconds. Therefore, I am looking for ND filter maybe 6-10 stops. I tried finding one what would fit my Bay1 Yashica but no luck. So, I found one from BH that is 2.25 square ND 6 stops. Question is- I shoot mostly with Acros 100 is there a repriocity for this film I need to be aware of for exposures up to 1 minute? I used ND with digital but never with film, does it have any "ill" effects on film that I should be aware of. DO I just meter and compensate for the filter?

Available in Bayonet 1 mount, with factors ranging from 2-1000:

http://www.heliopan.de/produkte/graufilter/

and on page 10 at their pricelist.


(Their factor 1000 filter is not neutral, though designated ND.)

Your choice of Acros will likely spare you reciprocity problems, it's pretty good out to the minute or two range. I have ended up with an assortment of adapters from Bay 1 to other sizes, as I find the Bay 1 filters don't appear to be as widely available.

Determine your exposure as usual with the filter off the lens. Once you have your exposure calculated add the filter and apply the adjustment for the filter based on the manufacturer's recommendation ( in this case a 6 stop adjustment).l


Best regards,

Bob
CEO CFO EIEIO, Ret.

There are Bay I to threaded adapters available. I've used a Bay I to 52mm adapter with a Yashica, and the slight extension into the viewing lens area makes no difference on the focusing screen (no vignetting or such). This is one solution to using Bay I with filters. I've seen 49mm and 46mm adapters.