Jump to content


Photo

Bad Super 16mm conversion


  • Please log in to reply
39 replies to this topic

#1 Nigel Smith

Nigel Smith
  • Basic Members
  • PipPip
  • 55 posts
  • Other
  • London

Posted 31 October 2007 - 05:49 AM

Hi
I took over caring for 3 H16 Bolexes in a university facility a couple of years ago. The cameras were converted to Super 16mm about 5 years ago, here in the UK.
After a couple of complaints from students i did some camera tests recently, and discovered that the framing is significantly out on the reflex viewfinder on all 3 cameras. They have a 'shift' of around 20% to the right, and one of them is also rotated about 20% clockwise ie crooked!
I found a new camera engineer recently, who used to work for ARRI [we have an SR2 as well as the Bolexes], and he is attempting to re-align the cameras. He says that a shift of a few % is not uncommon, but our cameras are spectacularly bad.
Has anybody out there experienced similar problems with conversions?
  • 0

#2 Nick Mulder

Nick Mulder
  • Basic Members
  • PipPipPipPip
  • 1023 posts
  • Other
  • Auckland, New Zealand

Posted 31 October 2007 - 06:37 AM

When they were converted to super16 is when the misalignment probably happened...

The holes in which the gate screws go through have reasonably large tolerances and there is also the screws that hold the whole prism mechanism down.. they sit in slots which can be moved both up and down... Basically, whenever any work is done with any of this there will most probably be a misalignment

Not to mention the convex-planar lens that sits atop the prism is removed for modification and is replaced with a simple mask at the new aspect, this is where the actual alignment is done once all the other fiddling mentioned above is complete...

Its pretty easy - it is held on by two screws so loosen them, now blast a light like an LED torch down the eye piece of the finder and then look at the prism from the front - you should now see the ground glass all lit up and showing your super16 mask ... - now set your camera to bulb mode and open the shutter (or simply run it if you have an EBM or EL) - now align the illuminated mask with the gate (takes a bit of fiddling and a light touch) - within reason the 'straighter' you are and the further you are away from the prism to remove problems with parallax the better, my results just from eye are fine as the mask is slightly smaller than the frame in any case (a small safety) - rotation is much worse than shift though - ouch!

Anyways... done ? cool !

so screw the two screws back down and double check to see the screwing down didn't move the mask again ...

easy ! (and free)

now - you might find that in your finder view the mask in its proper position is now off to the side and obscured by finder internals - easy fix again... open up the top of the finder and adjust the sprung adjustment screws on the 90deg prism at the front until it lines up somewhere the whole frame can be seen and is not obscured (they usually don't need much movement at all)
  • 0

#3 Nigel Smith

Nigel Smith
  • Basic Members
  • PipPip
  • 55 posts
  • Other
  • London

Posted 01 November 2007 - 05:11 AM

Wow!
Thanks a lot Nick.
what an excellent explanation. :D
  • 0

#4 Nick Mulder

Nick Mulder
  • Basic Members
  • PipPipPipPip
  • 1023 posts
  • Other
  • Auckland, New Zealand

Posted 01 November 2007 - 05:51 AM

To answer your original question - I'd say either a bad original super16 mod is to blame or the gate or mask screws (or both) got loose over time, which again is most likely due to them not being fastened correctly during the modification ...

Any idea who did it ?
  • 0

#5 Nigel Smith

Nigel Smith
  • Basic Members
  • PipPip
  • 55 posts
  • Other
  • London

Posted 20 November 2007 - 08:14 AM

To answer your original question - I'd say either a bad original super16 mod is to blame or the gate or mask screws (or both) got loose over time, which again is most likely due to them not being fastened correctly during the modification ...

Any idea who did it ?

Sorry it took me a while to find out :)
Martin Stent did the conversions in 2000.
The camera with the crooked mask has been straightened.
The parallax shift cannot be corrected though. :(
Apparently the main casting of the front turret above the prism is masking the view.
It should have been machined away? but it has 2 optics sitting on it which would then be unsupported...
The aperture of 12.mm is blocked by 1.4mm, so the film captures more image camera right than the viewfinder sees - by about 10%.
Apologies if this makes no sense.

To cut a long story short, Mr Stent is no longer on my christmas card list!
  • 0

#6 Don Brown

Don Brown
  • Basic Members
  • PipPip
  • 89 posts
  • Sound Department
  • The Original Boston UK

Posted 20 November 2007 - 10:50 AM

Sorry it took me a while to find out :)
Martin Stent did the conversions in 2000.
The camera with the crooked mask has been straightened.
The parallax shift cannot be corrected though. :(
Apparently the main casting of the front turret above the prism is masking the view.
It should have been machined away? but it has 2 optics sitting on it which would then be unsupported...
The aperture of 12.mm is blocked by 1.4mm, so the film captures more image camera right than the viewfinder sees - by about 10%.
Apologies if this makes no sense.

To cut a long story short, Mr Stent is no longer on my christmas card list!

Hi
Have you tried talking to Martin as far as I know he has done many conversion for David Warren who up until a couple of years ago before he retired was the top service engineer for Bolex in UK.

Regards

Don
  • 0

#7 Jean-Louis Seguin

Jean-Louis Seguin
  • Basic Members
  • PipPipPipPip
  • 719 posts
  • Other
  • Montreal, Canada

Posted 20 November 2007 - 12:32 PM

Sorry it took me a while to find out :)
Martin Stent did the conversions in 2000.
The camera with the crooked mask has been straightened.
The parallax shift cannot be corrected though. :(
Apparently the main casting of the front turret above the prism is masking the view.
It should have been machined away? but it has 2 optics sitting on it which would then be unsupported...
The aperture of 12.mm is blocked by 1.4mm, so the film captures more image camera right than the viewfinder sees - by about 10%.
Apologies if this makes no sense.

To cut a long story short, Mr Stent is no longer on my christmas card list!



Hi Nigel,

I have converting Bolex cameras to super16 here in Canada since 1994.
You are right about the part of the casting that should have been machined. It should have.
This would enable the shifting of the rhomboid prism a little to give better distribution of the light.
The two condenser lenses are eliminated anyway as part of the conversion as they are redundant.
They provide too much magnification for the widened groundglass frame.
The end result is a viewfinder image that is a little smaller but at least you can see everything clearly.

Cheers,
Jean-Louis
  • 0

#8 Nick Mulder

Nick Mulder
  • Basic Members
  • PipPipPipPip
  • 1023 posts
  • Other
  • Auckland, New Zealand

Posted 20 November 2007 - 02:16 PM

right,

my description works for the newer H16's with the magnifying optic that is mounted directly above the prism (as in onto it) - yours is an RX4 (or five?) that has the older more slightly more destructive/problematic design for conversion ...

Posted Image

more info here:

http://www.sci.fi/~a...to/s16/s16.html

Hopefully your turret has already been modified correctly and had a proper re-centre of sorts - have a read at that site and see the different options ... I'm scared your conversion may have just been widening the gate and bodging the finder !

BTW: a quick way to find out if the lens mount is centered is to put a vignetting lens on the front like a wide with heaps of filters on it ...
  • 0

#9 Nigel Smith

Nigel Smith
  • Basic Members
  • PipPip
  • 55 posts
  • Other
  • London

Posted 21 November 2007 - 04:29 AM

Hi
Have you tried talking to Martin as far as I know he has done many conversion for David Warren who up until a couple of years ago before he retired was the top service engineer for Bolex in UK.

Regards

Don

Hi Don
That's right - we went to Andrew Alden's repairer David Warren for the modification and he apparently passed it on to Mr Stent.
The cameras are currently with Simon Challenor, who is the "Officially accredited Service Engineer for Bolex here in the UK", and David's successor. He spoke to Mr Stent and found him at best "unhelpful" and denying all responsibility.
Thanks for the input
Nigel
  • 0

#10 Nigel Smith

Nigel Smith
  • Basic Members
  • PipPip
  • 55 posts
  • Other
  • London

Posted 21 November 2007 - 04:31 AM

Hi Nigel,

I have converting Bolex cameras to super16 here in Canada since 1994.
You are right about the part of the casting that should have been machined. It should have.
This would enable the shifting of the rhomboid prism a little to give better distribution of the light.
The two condenser lenses are eliminated anyway as part of the conversion as they are redundant.
They provide too much magnification for the widened groundglass frame.
The end result is a viewfinder image that is a little smaller but at least you can see everything clearly.

Cheers,
Jean-Louis

Thanks for the info Jean-Louis :)
Nigel
  • 0

#11 Nigel Smith

Nigel Smith
  • Basic Members
  • PipPip
  • 55 posts
  • Other
  • London

Posted 21 November 2007 - 05:01 AM

right,

my description works for the newer H16's with the magnifying optic that is mounted directly above the prism (as in onto it) - yours is an RX4 (or five?) that has the older more slightly more destructive/problematic design for conversion ...

Posted Image

more info here:

http://www.sci.fi/~a...to/s16/s16.html

Hopefully your turret has already been modified correctly and had a proper re-centre of sorts - have a read at that site and see the different options ... I'm scared your conversion may have just been widening the gate and bodging the finder !

BTW: a quick way to find out if the lens mount is centered is to put a vignetting lens on the front like a wide with heaps of filters on it ...

Thanks a lot for the info and link Nick.
This forum certainly is an excellent resource :)
Unfortunately the cameras are not currently here for me to examine but I am starting to suspect that your fear may be proved right. :(
  • 0

#12 Nigel Smith

Nigel Smith
  • Basic Members
  • PipPip
  • 55 posts
  • Other
  • London

Posted 21 November 2007 - 05:53 AM

Thanks a lot for the info and link Nick.
This forum certainly is an excellent resource :)
Unfortunately the cameras are not currently here for me to examine but I am starting to suspect that your fear may be proved right. :(

The edit post function won't work for me on this forum :(
I forgot to mention - the cameras are RX4s.
  • 0

#13 Don Brown

Don Brown
  • Basic Members
  • PipPip
  • 89 posts
  • Sound Department
  • The Original Boston UK

Posted 21 November 2007 - 05:43 PM

Hi Don
That's right - we went to Andrew Alden's repairer David Warren for the modification and he apparently passed it on to Mr Stent.
The cameras are currently with Simon Challenor, who is the "Officially accredited Service Engineer for Bolex here in the UK", and David's successor. He spoke to Mr Stent and found him at best "unhelpful" and denying all responsibility.
Thanks for the input
Nigel

Hi Nigel
OK on that when I was thinking of having my RX5 done Andrew recommended David Warren who at the time was the UK service agent but sent all his S16 mods to Martin, so where to send now I will give Les Bosher a call and get a price from him but with the £ strong against the $ it might be cheaper in the States, glad you have found Simon I found his Website in my files is out of date and I can not access it.

Don
  • 0

#14 Nigel Smith

Nigel Smith
  • Basic Members
  • PipPip
  • 55 posts
  • Other
  • London

Posted 22 November 2007 - 05:02 AM

Hi Nigel
OK on that when I was thinking of having my RX5 done Andrew recommended David Warren who at the time was the UK service agent but sent all his S16 mods to Martin, so where to send now I will give Les Bosher a call and get a price from him but with the £ strong against the $ it might be cheaper in the States, glad you have found Simon I found his Website in my files is out of date and I can not access it.

Don

Cheers Don.
PM me if you want Simon's contact details - he is based in Uxbridge.
  • 0

#15 Don Brown

Don Brown
  • Basic Members
  • PipPip
  • 89 posts
  • Sound Department
  • The Original Boston UK

Posted 22 November 2007 - 10:12 AM

Cheers Don.
PM me if you want Simon's contact details - he is based in Uxbridge.


Hi Nigel
Thanks for that, found his number in my little book


Don
  • 0

#16 Craig Mieritz

Craig Mieritz
  • Basic Members
  • PipPip
  • 26 posts
  • Other
  • Los Angeles, CA

Posted 07 December 2007 - 04:50 PM

Hi Nigel
Thanks for that, found his number in my little book


Don



I am quite surprised at the quality of some of the S16 conversions out there. I have a camera where the frame was off vertically by 1/4 frame and horizontally by nearly as much. The glue on the ground glass looks like it was applied by a grade schooler. If anyone is thinking about converting a Bolex, or purchasing a converted camera, send me a PM and I'd be happy to discuss my experience and what I've learned. I would definitely recommend having the camera looked at by a professional before purchasing it if it is already converted. And if you buy it on eBay, even if they swear that it's "ready to shoot", plan on spending $500 on servicing. The "official" Bolex repair person in the U.S. refers conversions to JK Cameras in the San Francisco Bay area. http://www.jkcamera.com/Super16.htm
  • 0

#17 banba ban

banba ban
  • Basic Members
  • PipPip
  • 28 posts
  • Cinematographer

Posted 08 December 2007 - 07:58 PM

I had an RX5 converted to S16 in the States a few years ago from a well known and supposedly reputable company.
I was not happy with the results to say the least...
I then sent the camera to Bolex in Switzerland and their conversion was excellent.
I have had no problems with the camera or conversion since and wish I had opted for the factory conversion in the first place.
Just my 2 cents...
  • 0

#18 Craig Mieritz

Craig Mieritz
  • Basic Members
  • PipPip
  • 26 posts
  • Other
  • Los Angeles, CA

Posted 09 December 2007 - 05:20 PM

I had an RX5 converted to S16 in the States a few years ago from a well known and supposedly reputable company.
I was not happy with the results to say the least...
I then sent the camera to Bolex in Switzerland and their conversion was excellent.
I have had no problems with the camera or conversion since and wish I had opted for the factory conversion in the first place.
Just my 2 cents...



From the stories I have been hearing about conversions gone bad, it seems like a factory conversion would be the safest route. I know the other vendors are substantially cheaper, but once you start paying to fix the original conversion, I don't know how much money you will have saved, and you don't have a camera to use while you are messing around with it. I guess it all goes back to "if it seems too good to be true, it is."

Dieter, a Bolex factory trained technician (http://www.bolex-usa.com/), made it very clear to me that he did not want to work on after-market S16 conversions to Bolex cameras. That is also something to consider. If something goes wrong with the conversion or the camera, you will need someone reputable to repair it.

And I would reiterate for the second time, if it's on eBay, think really hard about how much effort (and money) you are going to be willing to put into getting the camera into perfect running order before you bid.
  • 0

#19 Nick Mulder

Nick Mulder
  • Basic Members
  • PipPipPipPip
  • 1023 posts
  • Other
  • Auckland, New Zealand

Posted 09 December 2007 - 09:42 PM

I am quite surprised at the quality of some of the S16 conversions out there. I have a camera where the frame was off vertically by 1/4 frame and horizontally by nearly as much. The glue on the ground glass looks like it was applied by a grade schooler. [/url]

eh???

Glue ? There aint no glue that needs to be involved installing a super16 ground glass masking.

Anyone can check if the masking is correct by simply shooting a flashlight (LED is perfect) down the finder - it will light up the GG in reverse which will reveal the masking and by opening the shutter you can now at least eye the gate and maskings orientation with each other and screw it down once its ready... Due to the fact the gate aperture is usually larger than the mask this could be enough in lieu of a proper factory rigged alignment.
  • 0

#20 Craig Mieritz

Craig Mieritz
  • Basic Members
  • PipPip
  • 26 posts
  • Other
  • Los Angeles, CA

Posted 10 December 2007 - 01:17 PM

eh???

Glue ? There aint no glue that needs to be involved installing a super16 ground glass masking.

Anyone can check if the masking is correct by simply shooting a flashlight (LED is perfect) down the finder - it will light up the GG in reverse which will reveal the masking and by opening the shutter you can now at least eye the gate and maskings orientation with each other and screw it down once its ready... Due to the fact the gate aperture is usually larger than the mask this could be enough in lieu of a proper factory rigged alignment.



Yes, Nick, glue. Given your history, you're probably going to tell me my eyesight (and Dieter's) is fluxy (even if you've never seen the camera in question).

If it's glued too far out of alignment, you can't just loosen the screws to compensate, the ground glass needs to be removed and replaced correctly. This conversion was done by a well-known company (at least in the S16 conversion world). There are conversions out there with no frame markings, or worse. Unfortunately, there is no standardized process being followed by the vendors out there. If they all used the same process as Bolex uses, their conversions would cost as much. Buyer beware.
  • 0


CineLab

CineTape

Tai Audio

Media Blackout - Custom Cables and AKS

The Slider

Willys Widgets

rebotnix Technologies

Opal

Abel Cine

Glidecam

Wooden Camera

FJS International, LLC

Metropolis Post

Visual Products

Aerial Filmworks

Technodolly

Rig Wheels Passport

Paralinx LLC

Ritter Battery

Broadcast Solutions Inc

Gamma Ray Digital Inc

FJS International, LLC

Technodolly

Wooden Camera

Rig Wheels Passport

Ritter Battery

Opal

CineLab

Gamma Ray Digital Inc

Broadcast Solutions Inc

The Slider

Willys Widgets

Glidecam

CineTape

Visual Products

Media Blackout - Custom Cables and AKS

Aerial Filmworks

Tai Audio

rebotnix Technologies

Abel Cine

Metropolis Post

Paralinx LLC