Filmo 70DR - Best way to clean the critical focuser?

[Mark Eastman]

I've acquired a Bell & Howell Filmo 70DR in great shape, but that hadn't been used for a while. I lubed it with sewing machine oil and it works great. Was never really used that much based on cleaning the gate, not much film emulsion. The critical focuser, is viewable, however has a fair amount dust and residue. 

I obtained a copy of the B&H service manual and it mentions that special alignment tools are required and the focuser should not be removed or taken apart.

Is there a way to take this focuser apart and clean it without special tools? It looks like a modular unit with a mirror.

Or is this something best left for professional camera technicians?

It's not a major obstacle to using this camera, but it would be nice to have a clean critical focuser.

Thank you,

Mark Eastman
Palo Alto, California

 

 

Edited July 19 by Mark Eastman

[Simon Wyss]

You can remove the ocular which consists of one single lens or two, depending on the model you have. Caution, the retaining ring may be lacquered or glued in. Once out you can clean the ground surface, it stands perpendicular to the film. There is a prism with a silvered angled face, the front surface of which you can see and reach anytime. As long as you don’t remove the prism unit from its seat, nothing needs to be adjusted back.

The silvered surface can be defective (corrosion).

[Philip Forrest]

I have a few Filmos with critical focusing aids and only one is reasonably bright, the others are in varying states of tarnish or de-silvering and are basically done. They are really a pain in rear to use practically. Calibrate your lenses so the focusing scales are accurate then use a tape measure. The Parallax compensating tripod base is far better to use, in my opinion.

Edited July 25 by Philip Forrest

[Scott Barton]

On 7/18/2024 at 11:22 PM, Simon Wyss said:

You can remove the ocular which consists of one single lens or two, depending on the model you have. Caution, the retaining ring may be lacquered or glued in. Once out you can clean the ground surface, it stands perpendicular to the film. There is a prism with a silvered angled face, the front surface of which you can see and reach anytime. As long as you don’t remove the prism unit from its seat, nothing needs to be adjusted back.

The silvered surface can be defective (corrosion).

Thank you for this information, as I also have B&H 70 DR cameras and am trying to learn their intricacies - along with many other vintage pieces of cinema equipment...

So for me, all of these equipment-specific nuggets of information are pure gold.

 

[Scott Barton]

3 hours ago, Philip Forrest said:

I have a few Filmos with critical focusing aids and only one is reasonably bright, the others are in varying states of tarnish or de-silvering and are basically done. They are really a pain in rear to use practically. Calibrate your lenses so the focusing scales are accurate then use a tape measure. The Parallax compensating tripod base is far better to use, in my opinion.

Philip, thanks for the advisement on the silver degradation.

I have not done a real intensive inspection of my cameras yet, but I will be mindful of that condition...

[Mark Eastman]

On 7/18/2024 at 11:22 PM, Simon Wyss said:

You can remove the ocular which consists of one single lens or two, depending on the model you have. Caution, the retaining ring may be lacquered or glued in. Once out you can clean the ground surface, it stands perpendicular to the film. There is a prism with a silvered angled face, the front surface of which you can see and reach anytime. As long as you don’t remove the prism unit from its seat, nothing needs to be adjusted back.

The silvered surface can be defective (corrosion).

Simon, Thank you very much for this info!

Mark

Mark Eastman
Palo Alto, CA USA

[Simon Wyss]

Always around for Bell & Howell product users