Altman 902/Dyna Spot Bench Focus

[tcahall]

I have just become the proud owner of an Altman 902 and DynaSpot. I picked them up at an auction of a local high school. The DynaSpot is in good condition, the 902 in fair to good. I have cleaned them up and both work well (no more squeaks, etc.) The 902 is missing a lens that is still available from Altman, so I should end up with two serviceable follow spots for under $400 (1000-1500watt).

That being said, I am pretty confident that these were last bench focused at the factory 10-15 years ago. Does anyone have instructions on bench focusing these? They are pretty straight forward, so I don't mind jumping in, but a guide would be great.

Tim.

 

[church]

I have experienced problems with the bench focus on these units. I even resorted to measuring the positions of the lenses, reflector, lamp etc. on a good unit owned by someone else and found differences in the build between the unit that made the measured distances unusable. I have also seen the Conza and other lenses installed in both directions in units that perform better than mine.

Any insight from someone with the battle scars of doing a bench focus on these units is appreciated. I have called Altman with no success.

 

[ship]

Sorry, never worked on one but I'll have a look at some of my old manuals to see in the morning. Otherwise, there are old timers still at Altman, just got to get in touch with the right person.

 

[church]

Any suggestions on who to ask for?

 

[ship]

contact them during eastern standard time, explain the problem and hope for the best. Otherwise get your main supplier of gear involved as the go between in getting the right person to help. Discontinued gear don't mean you won't get an expert if you keep on the line or trying.


On the other hand, if you search back to much earlier posts and techniques with my experiences with Q1000 spots and the Kliegl Dyna Beam, there might be some hints between scribing the rails and just simply cleaning and oiling than focusing as it were with what you can. Shouldn't be that difficult, it is a latter fixture and made to bench focus somehow so by way of some knob or set of screws you should be able to do so. I'm sure it is designed for that purpose. Blank wall and tinkering is what I would do.

 

[church]

I will call Altman again.

The lenses and reflector can all be adjusted by loosening the lock screws that grip against the two rods that form the optical bench.

The challange is finding a reasonable starting point. I marked the original locations for each of the lenses and the reflector but was unable to find a good bench focus. I have tried selecting positions from another Dynaspot but it has dsign differences. The problem is that I repeatedly end up with an image where you can clearly see the overlap of the three lenses. I cannot get a sharp single image.

I have tried this with thefocusing ls in different positions again with no success. I have checked the focal length of the lenses against the Altman information available from their website and these are correct.

The unit I have does not work as well as the other unit I compared it against but the one that works well has a longer optical bench and lenses with the convex surface facing in the other direction to my unit and to what the Altman manual shows.

 

[church]

I have now fixed the bench focus problem with the help of Altman and very helpful and knowledgeable individual (Bob) at a rental shop that Altman (Kevin Fisher) introduced me too.

It appears that at sometime in its life someone had taken it apart and reassembled it incorrectly - not helped due to an error in the manual. Anyway there was more than one error in this reassembly and I have now achieved a good focus after completely stripping and rebuilding all the optics including repositioning the iris.

One item I find very helpful when doing a bench focus on this type of followspot where you have to remove the cover is an auto darkening welders helmet (I used to you gas welding goggles) and a welders leather jacket with mechanics gloves. Protects you from the UV, the heat, the light and any quartz in the unlikely event the lamp explodes.

This type of bench focus should not be attempted without appropriate safety equipment and certainly not by school students.