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Bold

Seeking Info About the B&H Projection Lens

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proto5.jpg

My initial test was disappointing.  The mod seems to suffer the same issue QuickHitRecord mentions near the bottom of the first post in this thread, where it can't quite seem to get to infinity.  The taking lens is a Helios 44 (not 44-2) that focuses to infinity just fine on its own and is flat up against the back of the B&H.  The front element of the mod  is sitting in the helicoid nearly touching the front glass of the anamorphic.

John Barlow mentions a negative achromat further down in the same thread as a solution.  Anyone know of this and how to acquire one?

Richg101 (or any other B&H modders out there) do you have any other thoughts/suggestions?  I'm hesitant to shorten the distance between the front glass and anamorphic any further because I'm worried about the glass touching each other.

On a positive note, the long helicoid allows me to focus down to about a foot (maybe less!) on my Helios without noticeable vignetting.  Some mighty focus breathing, though. I'm very close to finishing this mod and would hate to think all my effort has been for naught.  Any help on this issue would be greatly appreciated!

|. . | .|

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Bold, I applaud your efforts, the mod is looking good.

Regarding the infinity focus issue, I believe it is a flaw of the B&H itself. It simply cannot focus to true infinity.

I was also wondering if you've saved the design for the 3D printed parts and could share it. Maybe I can find some workshop where I can do it in my country and try your mod as well.

BTW, I see that redstan is selling his original clamp on ebay: http://www.ebay.com/itm/finest-anamorphic-lens-clamp-kowa-isco-sankor-and-more-by-redstan-/331812493831?hash=item4d4190da07:g:0NUAAOSwQYZWzlcS

This clamp is a perfect snug fit for the B&H with the silver ring attached (I have it).

Cheers!

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Thanks Gabriel!

Rich posted some pictures earlier in this thread which shows his mod focused at infinity, so it be should achievable on mine (in theory).

The 3D printed collar only works with the polyurethane piece (this is the part that physically screws onto the front of the B&H) that I made for myself.  Without that, the 3D printed part is of no use to anyone. I may consider recreating the whole assembly and selling it, but not until I can resolve some quality control issues - and hopefully the infinity issue.

A note about helicoids: the ones on eBay from China that I've gotten use a terrible lubricant which loses viscosity at lower temperatures.  Basically the rotation is very stiff when it gets cold.  If you experience this problem, you can disassemble the helicoid (don't lose the screws!), remove the grease lubricant and replace it with some white lithium grease for much better focusing action (although reassembling a helicoid in the correct order takes some patience!).  This is actually the first thing I do now when I get a helicoid from eBay.

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A friend of mine had a bit of a genius idea.

  1. Take a piece of lens tissue and put it between the glass elements, assemble everything and tighten/adjust the helicoid so the front glass element just barely touches the anamorphic with the tissue in between.
  2. Mark the position of all pieces on the outside of the mod.
  3. Disassemble the mod, remove the tissue, then reassemble and tighten/adjust everything to the markings, effectively getting to the two pieces of glass as close as possible without them touching.

It may not be enough to resolve true infinity, but the unit may be able to focus far enough to mitigate the issue.  I'll try this when I get home.

I'm still wondering about John Barlow's negative achromat solution, and what kind of focal length I would need?  Achromat math still confuses the hell out of me no matter how many times I read about it.  I found a 55mm diameter lens with a focal length of -4000mm.  Is that even in the ballpark?

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screenstest.jpg

No luck.  I think there still may be 1-2mm of space between the elements due to the construction of the parts, which I don't know if I can resolve.  I don't know if that extra millimeter or two is enough to make a difference.

On the plus side I measured and I can focus down to 8 inches.  Unfortunately it does not offset the infinity issue for me - what's the point of widescreen if you can shoot some nice, crisp landscapes, right?

I'm pretty despondent at this point...

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Through a combination of small arms fire and hand-to-hand combat techniques, I was able to get this:

screenstest2.jpg

The apartment in the background is at least 300ft away.  It may not be perfectly crisp infinity, but it's within an acceptable margin of error for my uses.  

Eight inches out to (good enough) infinity, single focus, no vignette (probably down to 50-55mm), light weight, 2x anamorphic. HUZZAH!

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Interesting:

I began work on modifying my second B&H and noticed that the front element has no black paint on the side, while my first one does.  My guess is that Bell & Howell added the step of painting the element during production of this lens.  I suspect the unpainted version is the cause of (or adds to) excessive/barrel flare that some people have experienced.  If you're brave and have a steady hand, painting the sides matte black is an easy improvement.

Also, I'm considering making a mod kit for B&H owners that would include my customized helicoid, plus the custom lens support, along with instructions.  If there are enough people interested, and I can figure out an acceptable price point...

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I want to take a moment to thank everyone who contributed to this thread.  Tito, Gabriel, Nahua, and particularly Rich, for your support and the invaluable information you shared that allowed me to get from 'novice anamorphhc modder' to 'slightly-less-novice anamorphic modder.' :)  Seriously, without your insights I never would have finished this mod.

proto6.jpg

I now have three working B&H lens mods.  Two have the 14mm helicoids, allowing focus to approx 36 inches, and the 30mm helicoid which provides an amazing 8-inch focus distance.  The downside on the 30mm helicoid is that:

  • It still requires several barrel rotations to rack focus from 8 inches out to infinity
  • Focus breathing is noticeable particularly at close distances.

Not a bad trade-off, to be able to so close with the camera.  I'm going to keep one of the 14mm's as well as the 30mm.  I've ordered parts to create a second lens bracket, and will bundle that with the remaining 14mm helicoid modded lens for sale on eBay, to recoup some of my costs.  As mentioned, I'm thinking of making the helicoid mod & lens bracket available as a kit if enough B&H owners are interested.  So let me know if you are.

Now I'm ready to start taking my rig out to do some serious test footage.  I'm especially interested in trying my Mamiya Sekor 50mm f1.4 and my Angenieux 12-120mm to see results of night shooting and zooming, respectively.

Once again, a thousand thank-yous to everyone in this thread for your help.  You've allowed me to realize my goal of shooting in widescreen, an ambition I've had every since I bought my first 8mm movie camera so many years ago.  I hope the info in this thread has helped other B&H owners take advantage of this lens.

Cheers,
|. . | .|

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Bold, summer is here and I finally got time to go over ALL THE POSTS here. Wow, man, I admire both your perseverance and the amount of detail you packed here.

I would be down to buy a mod kit from you and would straight out make a video about it and about how awesome of a guy you are by making it all public here. I think this should get you at least some extra visibility in the lands of facebook, and possibly sell more mod kits. Let me know if you're interested. :)

After the video is done, I'm likely to sell my B&H, as I'm downsizing my overall lens collection.

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On 4/26/2016 at 3:19 AM, Tito Ferradans said:

Bold, summer is here and I finally got time to go over ALL THE POSTS here. Wow, man, I admire both your perseverance and the amount of detail you packed here.

I would be down to buy a mod kit from you and would straight out make a video about it and about how awesome of a guy you are by making it all public here. I think this should get you at least some extra visibility in the lands of facebook, and possibly sell more mod kits. Let me know if you're interested. :)

After the video is done, I'm likely to sell my B&H, as I'm downsizing my overall lens collection.

Let me know if you want to sell your B&H :)

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Guillaume,

I have mods with both sizes, and they both work fine. If focusing closer than 1m is not that important to you, the 17-31mm will fit your needs.  But the 25-55mm helicoid is only a little more expensive than the 17-31mm, so I think it's worth getting the 25-55mm to get that extra close focus.

 

Cheers,

|. . | .|

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A small update to B&H modding: I’ve been using the silver Series VII ring that comes on the back of most B&H’s found on eBay.  I made a polyurethane version for Tito since his did not come with one.  The ring is great for adapting to whatever taking lens you’re using.

On a whim I decided to take off the silver ring to see if I could get my Helios any closer to the back of the anamorphic.  Here’s the back of the B&H without the silver ring.

bh01.jpg

Since my Helios has a diameter of less than 61mm (which is the inner diameter of my support bracket), I was able to slide it closer so that the back of the B&H is actually sitting inside the taking lens.  

bh02.jpg

bh03.jpg

So the series VII ring isn’t necessarily needed in all situations. It doesn’t necessarily improve the resulting image either, but it is a snug fit.

bh04.jpg

In other cases, like if you have a taking lens with a 72mm thread, I would definitely recommend a 72mm-to-S7 adapter to ensure that your lenses are locked, light-sealed, and centered.

On Tito’s advice, I also took a 3D file for a follow focus ring, altered it, and fit it around the helicoid of my B&H mods.  It’s a much easier process than hand-gluing focus strips, and the results are a little nicer looking too.

bh05.jpg

Cheers,

|. . | .|

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Here's my badly photoshopped cross-section of what I mentioned above.  The narrowing inner cone of the Helios prevents the B&H from touching the glass of the taking lens.  You just have to slide them together with caution and care, to avoid scraping inner section of the taking lens.

bh06.jpg

2 hours ago, Tito Ferradans said:

I like the silver Helios!

Me too!  I picked up a couple 44-2's for cheap last year, but I haven't used them much because I love love love the image quality of the original 44. I'm probably going to take one of the 44-2's and do this since I have the Kowa glass as well. 

2 hours ago, Tito Ferradans said:

Great job, man. Shooting the tests with the mod was the most fun I had in a while! Video comes out this weekend. :)

Thanks Tito!  Can't wait to see the video... so glad you had fun with the mod !!!

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On 25 août 2016 at 5:27 PM, Bold said:

Guillaume,

I have mods with both sizes, and they both work fine. If focusing closer than 1m is not that important to you, the 17-31mm will fit your needs.  But the 25-55mm helicoid is only a little more expensive than the 17-31mm, so I think it's worth getting the 25-55mm to get that extra close focus.

 

Cheers,

|. . | .|

Many Thanks for your answer :) and for the Inspiration ;)

Even if I'm more into 8mm Anamorphots...you can easily imagine how important is all the info you're sharing here!
Actually I'm doing some tests with the original B&H single focus module attached to a Sankyoscope.
I have to say first tests are a bit disappointing... compared to the results I obtained with just taping the B&H inner diopter to the Sankyoscope and push/pulling focus, and all the misalignment induced. It's lightyears away from the results of the (bulky) Rangefinder Imp + Sankyoscope or Baby Hypergonar combo!
But I'm kind of obstinate so I will sure try to adapt your mod with the M58 helicoid and if it works I will share the results and details ;):)

Cheers!

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3 hours ago, Guillaume Regnaux said:

Actually I'm doing some tests with the original B&H single focus module attached to a Sankyoscope.
I have to say first tests are a bit disappointing... compared to the results I obtained with just taping the B&H inner diopter to the Sankyoscope and push/pulling focus, and all the misalignment induced.

Guillaume, good luck with your experiments - although I don't think kitbashing parts of the B&H with other scopes will get desirable results.  The B&H is not meant as an alternative to the FM module, SLR Magic Rangefinder, or the Rectilux Core DNA.  The B&H 16mm anamorphic 2x projection lens is a complete anamorphic in itself, ideally suited as a single-focus solution for micro four-thirds cameras.

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1 hour ago, Bold said:

 

Guillaume, good luck with your experiments - although I don't think kitbashing parts of the B&H with other scopes will get desirable results.  The B&H is not meant as an alternative to the FM module, SLR Magic Rangefinder, or the Rectilux Core DNA.  The B&H 16mm anamorphic 2x projection lens is a complete anamorphic in itself, ideally suited as a single-focus solution for micro four-thirds cameras.

OK... don't take it wrong... so why not just getting rid of the B&H module and pair its anamorphot with a proper $F Module? if not for experimenting?
B&H16 wasn't designed at all for filming purposes either ;) as none of the anamorphic projection lenses were...
If I'm not mistaken Alex Diehr modded a Rectimascop 64 (or 80?) and a Moller 63 with the glasses from the SF module of a Panatar (based on the same plano concave/convex optic design than the B&H). Seb Farges uses the SLR Rangefinder on the Baby Hypergonar. I've tried it myself both on the Baby H and the Sankyoscope.
Right now I'm not happy w the Baby's results, but I get a sharp 1 meter to infinity at f1.8 with the Sankyoscope... no streak flares, but real organic textures, ovals and waterfall bokehs ;) From a lens that shouldn't deliver better than 2 meters close focus at f4.0/5.6.

Just saying if the B&H formula is not ideal, it's 46mm diameter glass is a start to go on with the idea of a Micro SF Module. No?
I wish I had better knowledge in simple Maths, Optics and Mechanics to produce a better formula.
Just thought I could share the idea here... and maybe get some feedback from others experimenting ;)

Anyhow, Many Thanks again for sharing your work with that "Open Source" Spirit.
You can be sure if I succeed I'll follow your example ont that matter. Best!

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