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Seeking Info About the B&H Projection Lens

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Inspired by QuickHitRecord's excellent post, and this post here, I just acquired a Bell & Howell anamorphic projection lens like this one in very good condition.  

Does anyone out there own/use this lens?  If so, which taking lenses do you find work best?  Are you able to zoom through?  I'm hoping to find details on how to modify to the front element to reduce the focus throw, and really any details to get the most out of this lens.  Any pointers are greatly appreciated!

If I can collect enough info to make modifications safely, I'd like to document the process and post it back to the forum in case anyone else may find it useful.

 

Cheers,
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selecting a suitable helicoid (you can get various units with various diameters and focus throws on ebay) is a great start.  grab one that will allow you to fit the front element into it, - maybe with some step rings + nd filter rings with the glass removed to mount the glass.  then attach it to the front of the b+h.  I successfully did this and its a great mod.  i get focus from inf to around 3ft in around 90degres.  its nt a razor sharp lens, but almost gives full coverage wit ha 58mm on aps-c.  a 58mm and a gh2/3/4 will deliver great things.  lovely flare and character.

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Hi Rich - Thank you for your response!!!  This certainly seems like a more affordable solution than finding a machinist to fabricate a new front element.  I made the following diagram to make sure I understand the process:

bh-mod

  1. Transfer the glass from the B&H front element to a suitable helicoid (using step/filter rings as needed).
  2. The helicoid with the B&H glass then replaces the old front element and is joined to the rear assembly.
  3. The old front element is not needed and can be stored in case it's ever required again.

Is this correct?  If so:

  1. Which kind/brand of helicoid did you use (or would you recommend)?
  2. Will the helicoid require any adaptation or modification to join the rear assembly of the B&H?
  3. Which kind of step/filter rings did you use (or would you recommend) for the glass? 
  4. If you're able to go down to 58mm on aps-c with little or no vignetting, what would be the shortest lens usable on m43? 40mm-ish?
  5. And the million-dollar question: Since the B&H is doing the focusing and not the taking lens, can it be used with a parfocal zoom?

Thanks again for the info,  I'm excited to reach the point where I can start putting this modification together and share some test footage.  if anybody else has anything they can share, it would be hugely appreciated - I'm hoping to consolidate enough info to add back to the Anamorphic Lens-opedia.

 

Cheers,

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By the way, I have been told by a B&H user that the thread on the rear assembly of this projection lens is a Series 7 thread.  I will try to confirm as soon as I have money to start buying some parts...

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you only need about 15mm of travel.  i recon a m58 helicoid will work.  TBH i cant even remember which unit i used, i just ripped it apart to get it to do what i wanted.  mine wasnt the right size so i had to modify/step down.  just measure the body with the front element housing removed and select a helicoid that will slip over that.  if needs be you can pack it with pvc tape for a tight fit.

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Here are some images showing my quickly put together test.  literally ripped apart a m58 helicoid so it would slide over the original male thread of the original focus part.

 

The front element was fitted into the helicoid.  i'd meant to make it so the front element didnt rotate but in the process of reworking the helicoid I damaged it and therefore the front element rotates as you focus.  No big deal, but it is actually possible to do this mod and have the element non rotating.

As you can see in the pics the front part of the helicoid with the front element seated in place now unscrews.  I actually used a rubber o ring cut to the right length which i squished around the front element.  this naturally pushes it centre and is tight enough to hold the element in the front part.

 

two shots are show.  wide open at f2 on a 58mm lens on aps-c. (3:2).  one at infinity, one at around 3 feet.  rack from inf to 3ft is around 3/4 of a turn!

Closing to f2.8 sharpens stuff up drastically.  as does using on a smaller sensor - 4:3 4k mode on gh4 would be ideal for this lens

 

flares are wonderful by the way!  

 

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NB.  

 this method of modifying the B+H was showed to me by the good man Nick (QuickHitRecord), who was actually going to be manufacturing focus units for the B+H design and made the concept public on this forum long ago.   It was unfortunate Nick never got this to the manufacturing stage but i feel he deserves a pat on the back for making this public.  Hopefully some other people can make a working unit like this one.

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Here are some images showing my quickly put together test.  literally ripped apart a m58 helicoid so it would slide over the original male thread of the original focus part.

 

 Great insight! How exactly did you rip it apart? Did you use a dremel or something to modify it so that it would fit over the lens? Would really like to try this out on my own B+H. Also, how did you fit the front diopter lens on the helicoid? Does it have an exact m58 thread?

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So, I got this one

http://www.ebay.com/itm/131564846539?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

And I couldn't remove the spherical part of it. I've applied a lot of strength trying to unscrew it and got ZERO movement. The focus ring is also locked, seems like a screw, but I didn't look too much into it. Any suggestions on how to get the anamorphic out? It's also super heavy due to the projection lens.

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So, I got this one

http://www.ebay.com/itm/131564846539?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

And I couldn't remove the spherical part of it. I've applied a lot of strength trying to unscrew it and got ZERO movement. The focus ring is also locked, seems like a screw, but I didn't look too much into it. Any suggestions on how to get the anamorphic out? It's also super heavy due to the projection lens.

to remove the spherical section you need to unscrew the 2 screws near the seam between the writing on the anamorphic section and the ribbed part on the spherical section.  it will then unscrew off.

 

for the focus mechanism, remove the two screws on either side of the focus part.  it should unscrew.  if not, you will need to feed a very small amount of lighter fluid into each of the holes where the screws were.  literally a grain of rice worth of a drip per hole.  any more and you;re risk it going into the cememnted anamorphic part.  zippo 'petrol' lighter fluid will break down the dried up lubricant pretty quickly.  apply it with the front facing down so the fluid doesnt travel towards the anamorphic section.  

 

Once the front element housing is unscrewed (around 5-7 turns if i recall) you can then use a rubber handle of a screwdriver as a mallet to break the friction weld on the front element retainer ring.  A few sharp knocks on the front rim should break the bond, then a lens opening tool will do the rest.

 

 

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I think I'm having a similar problem to Tito.  I was able to unscrew the front section easily.  But I'm unable to unscrew the retaining ring/front element with a lens tool.  I rapped all around the rim with a rubber handle repeatedly.  I also used a syringe to apply the smallest amount of lubricant around the seam where the retaining ring meets the outer housing (yellow arrow) .

stuck.thumb.jpg.66a512885217cdaee1514b85

Nothing will budge.  I don't want to apply too much force to the lens tool for fear of slipping and scratching the glass.  Perhaps there's some kind of adhesive or glue that was used during manufacture to lock the front element once it was screwed in?  But I'm hesitant to use Naphtha or something that my damage any lens cement or coating.  Any ideas?

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the retainer ring is unlikely to have been threadlocked.  its more that it will have been tightened a little too much.  be more vicious with the tapping of the outer rim.  the element is a singlet so there is no balsam to sheer - or be damaged by heat/acetone applied to the lock ring to break any possible threadlock down.  you will definitely need to put some serious force onto the ring for it to unscrew.  lock the lens opening tool so it cant close down and slip, and put some serious force onto it if required.  it'll come away with enough force,  wear some rubber gloves so you have some good grip on the housing and the tool.

 

 

 

 

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I have banged this sucker up and down with the mallet, including using a dowel to tap the outer metal diameter between the glass and the rim on the back side of the housing. 

Excessive force with the lens tool has cause me to slip twice.  Glass is unharmed, but the surrounding metal now has some scrapes & one of the lens tool blades has deformed slightly.  This thing won't unscrew....I'm getting pretty disheartened about the whole thing.

What about heat?  Is it possible to heat it up in distilled water, to get everything to expand & loosen a little, without causing damage to glass/coating?

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Rich, sorry to keep pestering you...did you use anything else from the front assembly?what-about-this.thumb.jpg.ea7554314db28a

The part I outlined above sort of looks like the part from your photo below that I've highlighted.  Or is that the rubber o-ring you used:

what-about-this2.thumb.jpg.7f61578e820c7

I'm trying to determine what I need for securing the element to the helicoid because there is a lot of open space.

need-spacer.thumb.jpg.27aca3ebcc28868b14

Also, by your pictures it looks like you used something like electrician's tape for securing the helicoid to the anamorphic section.  Is that correct?

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I've ordered two different rubber rings in hopes that one of them will fit snugly around the lens and hold it firmly in the helicoid.  I also ordered some PVC pipe tape, some pipe thread sealant tape, and some shrink tubing...between those three I should be able to secure the helicoid to the anamorphic body.  Once the orders arrive I'll put it all together and - if successful - post the results back here.  I'm taking a few pictures as I go, hopefully they'll help other folks who want to try this mod.

Also, based on the conversation here, my curiosity was piqued about adding wide angle adapters to the front of the anamorphc, to offset the longer lens requirements of the B&H in order to avoid vignetting. I've picked up the following adapters:

Canon WC-DC58 | 0.8x
Raynox HD6600pro-58 | 0.66x
Century DS-55WA-58 | 0.55x
Vivitar VIV-67W | 0.43x

It looks like QuickHitRecord and nahua used the Sony VCL-HG0758 0.7x.  But after reading this I opted for the Raynox 0.66x because of the lower weight & less edge distortion.  Knowing the distortion was only going to get worse the wider I went, I opted for the Vivitar in the 67mm thread (instead of the 58mm) for the 0.43x.  My thinking is that the anamorphic looking through bigger glass will miss the more severe distortion at the outer edges.  We'll see.  Once I get the anamorphic together & working (fingers crossed) I'll do some test footage with various taking lenses as well as the wide angle adapters, and post results back here.  Vintage lenses I hope to test:

Sears 55mm f1.4
Helios 44 58mm f2
Helios 44-2 58mm f2
Jupiter-9 85mm f2
Nikkor-P 105mm f2.5
Angenieux 12-120mm f2.2 (to test parfocal zoom)
...Possibly a few others

Cheers,

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