Testing 1 2 3 Testing

[Allen Achterberg]

i will be testing a Bolex and a Beauliu, shooting 7278 kodak reversal stock. i want to check the mag, make sure its not scratching, and i want to test the pin reg. and maybe i need to test other things? im not sure, any ideas please feel free to give me all you gots. later on gentleman and gentelladies.

[Laurent Andrieux]

quiclky sais :

 

1) fixity test :

 

there is a special chart for this, but if you don't have any, just draw a big but thin cross, align it with your ground glass center cross, shoot a one minute footage underexposed one stop, re roll this neg into the camera and shoot the same cross a second time.

 

You need the camera to be perfectly tighten for this test, if it moves, it's ruined.

 

Project the exposed processed stock (don't do a print if negative) and see if a cross moves compared to another.

 

if it moves vertically, you have a problem with pin reg or stock movement tension...

 

if it moves horizontally, you have a problem of side pressure plate.

 

2) shoot a siemens star - project the neg. if the center pulses it's the rear pressure plate

 

3) lens test : you need Foucault charts and a binocular to do the test in the rules of the art. If you don't have one, you'd better give it to a service to check it up.

 

What you can easily do is : have a chart (newspaper is ok) at some distance like 2 or 3 meters away (about 10 feet) that is engraved on the lens. have the chart lighten so that the proper exposure would be wide open. First set the lens at longest focal length. Focus by eye. check that the engraved distance is the tape measured one. if not, take it to the service. if yes, do the test at 3 feet. Same conclusions.

 

Then enlarge. Does the focus stay or is it getting out ? if not, take it to the service.

 

if yes to both questions, do the test at 3 feet. Same conclusions.

 

 

4) ground glass check

 

frame this chart or newspaper f stop wide open, at a middle focal length (let's say 20 mm at 3 feet away ) with focus set by eye at this focal length, mark the focus you find on the ring, then do a 5 second shoot with the focus ring turned 10 mm away from this mark (at a closer distance), then 9 mm... to 10 mm over the mark (at a longer distance) each shoot must have a little slate on it on wich you should write : -10, -9...+10. Write somewhere the distance you found by eye.

 

Then project the test. Does the best image is the one shot at 0 ? if yes, the ground glass is good. It actually shouldn't be good only at this distance, but slowly get out of focus as you go away from zero, and should be better in the minus than in the plus (since you have more depth of field in the log distances than the short ones).

 

5) Frame test.

 

have the camera well tighten for this too. Mark the edges of the frame on your board or wall with little arrows that point the ground glass marks (easier if a friend places them while you look thru the viewfinder), two for each side, at a third of the dimensions. Shoot 2 seconds. then, examine the processed stock : do the arrows point the edges of the image ?

 

6) motor test : shoot a clock with a second-hand for a minute, does it take a minute when you project ?

 

7) scratch test : examine your rolls first when they come back from the lab. Use a torch or flash light (maglite) to precisely see if a scratch reflects the light on both sides.

 

if there are scratches though you cleand properly your camera with a cloth and orange wood stick, no traces of oil, stock bits..., send it to a service.

 

Or have a friend, 1st or 2 nd AC to help you out...

 

This was an improvised adaptation of the professionnal tests for you, hope it might help. Does anybody have any other idea, or would correct any mistake I might have made (some maybe due to my english missknowledge, sorry I'm french) for sure...