8mm Forum: Bolex H8 Rex exposure settings

This is topic Bolex H8 Rex exposure settings in forum 8mm Forum at 8mm Forum.

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Posted by Anton Juan-Jorge Caro (Member # 1012) on July 02, 2011, 02:13 PM:

Hi again.
Now. The case is the following:
These are my thoughts, which I would like to ask you to go through and comment if you think I commit a mistake somewhere.
Yesterday I came upon an article by Super 8 man about his H8 and the exposure settings on it... and I was shocked.
Why? I bought my Bolex 4 years ago, coming with an instruction manual. Fine. But yesterday I realized that the manual was of an earlier version, because in the manual it was explained that the shutter at 18 fps was 1/30, while in the article it was explained that the exposure at 18 fps was 1/60 and closing the shutter by 1 ... the speed is coming to ... 1/125.
Wow. I was shooting with the idea the shutter was operating at 1/30 ? And I was wondering WHY it happened that I was shooting the same emulsion with my photo camera resulting in different speed from the 8 mm version ... So, I was overexposing by 1/2 stop. Not too much.
The film is FOMA R 100, which I process in chemistry published by ORWO/AGFA, which I shoot (according to Czech amateurs using the same chemistry) as 200 ASA. So, I had to change the first developer processing time for the 8 mm film - from 12 min to 10 min, which means just one thing - OVERexposed.
The question to you is - Am I right that closing the shutter by 1 at 18 fps the effective exposure equals to 1/125 s ?
And I will shoot the film as 200 ASA. I will first process test shots done with my 35 mm Zeiss Ikon ZM and then use the same processing time for the 8 mm film.
Is it fine?

[ July 04, 2011, 11:33 PM: Message edited by: Anton Juan-Jorge Caro ]

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