Make your own helical focus mount [Archive] - Large Format Photography Forum

Darcy Cote

29-Aug-2010, 11:31

Hi there: making my own sinar handy with parts. Would like to know if anyone has used a bronica etrs lens helical or the removeable bronica S2 helical for ther own project. I have never seen an S2 helical so I don't know much about them. I am wondering which one would be better to use. I am using a fuji 65mm lens. So which bronica lens should I buy in mm?
Thanks Darcy

Joanna Carter

29-Aug-2010, 12:00

If you are building a Sinar, with bellows, why would you also want a helical focusing mount?

John Koehrer

29-Aug-2010, 12:06

It's a "handy" not a full featured camera, just a P&S.

Ash

29-Aug-2010, 13:27

I could really do with a helical mount for the Anschutz I modified...

Some people use SLR lens helicals, bigger the better. Raid a parts box at a camera shop?

Darcy Cote

29-Aug-2010, 15:55

The slr helical is too small. The rear element of the 65mm lens wont fit in a SLR helical.

Bob Salomon

29-Aug-2010, 17:08

Rodenstock makes helical focusing mounts for most of their lenses from 23mm to 150mm if the FFL of your Fuji lens matches the FFL of a Rodenstock 65 then the helical will work for your lens and properly reach infinity and have the correct distance and DOF scale. If not check against the SA 65mm. If it matches that then the Schneider helical for their 65 will work. Or get the Rodenstock or the Schneider 65 and the correct helical and sell your lens and save a lot of headaches.

Brian Stein

29-Aug-2010, 20:15

Options:
1. try get a helical from a med format thrasher body/lens and adapt $cheapish
2. buy a dedicated one from one of the name manufacturers as above $lots
3. buy a no-name one on a linhof board from ebay for about $125ish
4. buy a helical cone from gaoersi or similar for mounting a LF lens on one of their bodies and adapt $300ish

You are likely to need to do a little adjusting unless as Bob says you have the exact flange-film distance of the rodenstock or schneider lenses on your fuji.

Darcy Cote

29-Aug-2010, 22:28

I am building this thing to with as little cost as possible. Doityourselfers tend to do that. If I was to get the name brand helicals, it would defeat the purpose and I may as well buy a full fledged sinar handy. The original questions were about the bronica helicals nothing else. But thanks for trying to be helpful.
Darcy

jon.oman

30-Aug-2010, 12:05

I saw one helical salvaged from a large SLR zoom lens used in this manner. I don't think they used the focusing helical, but the zoom helical, which seemed to be bigger. The person bought the zoom lens from KEH, from the bargain bin. If I remember correctly, they paid less than ten dollars for it, since it was deemed usable for parts only. You may want to try that, since the cost is minimal.

Jon

Ash

30-Aug-2010, 14:54

Darcy it will depend on what lens you look at. There are very big lenses out there.... for example Mirror-Tele

Bob Salomon

30-Aug-2010, 16:29

Darcy Cote

30-Aug-2010, 20:04

I can understand your desire to make your own. But there are some major issues that you have to solve to make this work. The first is the FFL of your lens. If the helical is too long you can't focus to infinity. And if it too short you will also have a focusing problem in that you won't be able to focus to infinity unless you make an extension for the lens board to make the helical the correct FFL when it is fully retracted. How will you calibrate DOF and distance settings? Then the helical has to be large enough so the rear element fits inside it. These would eliminate nearly all MF helicals and most "junkyard" helicals. Ahh I am a builder guy. These are part of the enjoyable part to make something work. All these problems can be solved. Heck, I am finishing up on a 6x30 camera. Have you heard about one of those? But thanks for the concern. You do have some justification here. The lens rear element won't be a problem for medium format helicals but the helical does have to be short. If the helical is too short I adjust the rest of the camera/cone to fit. Too long...I will machine off the extra bit.

John Koehrer

31-Aug-2010, 09:03

I go along with Darcy, to do this kind of stuff you really have to think outside the box.
If you want to go crude, use telescoping sections of PVC pipe. One section or the other could be sanded down & lined with velvet or felt for a slip fit. Cut slot in one tube, add a guide pin & you can make a crude helical or if you use a threaded cap you could have a helical for cheap.

SocalAstro

2-Sep-2010, 19:09

Darcy,

I just took apart an old Vivitar 500mm f/8 mirror lens made for 35mm cameras and it is large enough to house my Nikkor 65mm SW lens, BUT it is too long to build a camera around as it is. I have to reduce it's length to something manageable to allow it to reach infinity focus as others have indicated.

I may build a second P&S 4x5 or 5x7 camera with this helical, but I'd have to use a longer lens (75mm-90mm).

Cheers,
Leon

Carsten Wolff

25-Nov-2010, 08:22

sorry, late piping in here...
A problem to be aware of if going down that route: With a lot of the [cheaper] helical options is that the lens will rotate, which ain't much fun, as the cable release and the aperture/shutter speed scales invariably end up in the most awkward positions, not even talking about attempts to add a flashsync cord......hilarious. So consider a proper non-rotating helix.

banjo

2-Dec-2010, 19:45

I just got a MAMIYA SEKOR 90mm LENS for a MAMIYA 23 got the helical focus mount
and lens all for $60.00 works great but don't quit do a 4x5 SO I thank I will put in my
90mm S-K Super Angulon in it as it is a #0 shutter any way
banjo

banjo

7-Dec-2010, 15:23

hey all
I have been working on my Century Graphic 2x3
what was trying to do was get a helical focus mount
to put a Super-Angulon 5.6/47mm maybe Super-Angulon 5.6/65mm
or a Angulon 6.8/65mm ! the Super-Angulon 5.6/65mm has a #0
shutter that why I got the MAMIYA SEKOR 90mm LENS for a
MAMIYA 23 got the helical focus mount is it has a #0 shutter
But it to big to put on a 23 Century ! so now I have a Kodak Retina Ia
Rangefinder w/ Zenar f3.5/50mm Lens parts camera coming to
use the helical focus part of it on my Century . the Retina Ia has a #00
shutter so I can put my Angulon 6.8/65mm shutter & lens on it Or keep
looking for a good buy on a Super-Angulon 5.6/47mm as it is also uses
a #00 so it should work TOO you may ask why I am doing this that to
use a 47mm on the Century is hard to use the focus is hard to do with
the bed in the down position with the helical focus mount I can put the bed
in the down position out of view of the lens & still focus the lens
so I will maybe use the MAMIYA SEKOR 90mm LENS for a MAMIYA
23 got the helical focus mount some day BUT for what Darcy Cote
is trying to do a Mamiya 23 got the helical focus mount mite work for
him as some the cost is not that bad

banjo

Leigh

7-Dec-2010, 21:35

I have a number of new (NOS) zoom lens helical focus assemblies, cheap.

If you're interested I'll check the diameters. They're pretty large.

- Leigh

erie patsellis

11-Dec-2010, 16:14

leigh, I for one would be very interested

BetterSense

11-Dec-2010, 17:27

I made a helical mount for my cigar box camera using an old JC Penny 35mm SLR lens. It fits my 90mm Angulon easily and focuses down to 5 feet.

Steve Smith

12-Jan-2011, 02:21

Here is my contribution. Some of you may have seen this before.

http://stevesmithphoto.webs.com/pano612.html

Steve.

12-Jan-2011, 10:11

The ebay $125 helical mount I have. I haven't measured it with calipers but I'd guess it allows about 3/8" upto 10mm of focus adjustment range. It's not huge, but should be fine for wide angle adjustment as long as you are not trying to do closeups. I bought it to allow more lens options on my gowland aerial (every lens has a different flange distane) and it will suit that purpose fine. They were willing to provide one without the preprinted stuff that shows on the ebay auction.

The focus is fairly stiff at first and should not come out of adjustment accidentally. For casual focusing one might want to add a grippy rubber band or otherwise textured surface. It comes as black aluminum.

Leigh

12-Jan-2011, 12:10

As I mentioned previously, I have a selection of NOS helicoids from 35mm zoom lenses.

Here's a drawing of one type: http://www.mayadate.org/pix/VivHel01.pdf

... and his pic:

http://www.mayadate.org/pix/VivHel01picq.jpg

This one has a clear ID of ~2" and a throw of ~1". Other types are about the same diameter, but with longer or shorter throws and slightly different configurations.

These are factory assembled and lubricated, each in its own little plastic bag.

Note that these are internal lens components that will require additional parts for a complete functional installation.

Let me know if there's any interest.

- Leigh

domaz

12-Jan-2011, 14:39

Pentax 6x7 lenses are pretty darn big. Some of them take 82mm filters, if you can find an Ugly one and take the glass out and other unnecessary bits out they could work for 65mm I think. The problem could be there are mostly long though- finding one short enough to use for wide angle lenses could be difficult.

BetterSense

12-Jan-2011, 15:15

Here's something I thought of, and this might be slightly OT:

Bronica, some Pentax, and I think Hasselblads, have lenses with in-lens leaf shutters. Is there any way to trigger these lens' shutters? If so, you could make a box camera and have full focusing capability along with in-lens shutter. But it would only cover medium format, but still.

Leigh

12-Jan-2011, 16:31

...Hasselblads, have lenses with in-lens leaf shutters. Is there any way to trigger these lens' shutters?
It would be difficult.

The Hasselblad shutter cock and release functions are controlled by a rotating shaft in the camera body, aligned coaxially with the lens.

Duplicating its operation would be a challenge, but not impossible.

- Leigh

BetterSense

12-Jan-2011, 17:26

I was hoping it was something as simple as a cable release socket. I'm pretty sure I've seen a Pentax 6x7 camera that had lens with a cable release socket directly on it.

Steve Smith

13-Jan-2011, 01:33

Here's something I thought of, and this might be slightly OT:

Bronica, some Pentax, and I think Hasselblads, have lenses with in-lens leaf shutters.

It took all of my powers of self control not to take one of my Bronica ETRS lenses apart to use the helical. I tried to find a broken one for sale but couldn't. I think they are big enough to take most LF lenses and as the focus ring is at the body end, most of the superfluous lens stuff can be removed.

I would still like to try one so if anyone has a broken ETRS or SQ lens they would like to get rid of, let me know.

Steve.

Photomagica

14-Jan-2011, 23:49

I've used the Fotoman Helical to build a camera and think they are well made a very good value for the money. Here is the link:http://www.fotomancamera.com/accessories_list.asp

If you can scrounge a helical and don't mind the work of adapting it - great. I've done that too, but in this case a client was paying my machining time and a stock helical saved him quite a bit.

Cheers,
Bill

Jeicob

15-Jan-2011, 05:06

Some 40 years ago my father build this and I've been told that helical itself came from a Bronica
(the hard part should have been the screw in mounting on the front plate keeping infinity at top and all)

http://static.londonfgss.com/attachments/15539d1253896562-graflexswc-005.jpg
SA 47/5.6 with Graflex (Graflock?) back and cassettes for 6x9, 6x7 and 6x6. The helical will focus from infinity down to one feet.
It's now obsolete as I recently bought a Sinar Handy (http://www.largeformatphotography.info/forum/showpost.php?p=662605&postcount=3) and it will be up for sale if anybody would be interested to buy or trade!
The empty frame could be used to create a front/body for other lenses ;)

Asher Kelman

29-Nov-2011, 20:06

Asher Kelman

29-Nov-2011, 20:08

Here is my contribution. Some of you may have seen this before.

http://stevesmithphoto.webs.com/pano612.html

Steve.

http://stevesmithphoto.webs.com/pano612_files/image325.jpg

Steve,

What's your CNC machine? This is one of the most beautifully crafted mods I've seen. How good is your calibration of your cone and what does it weigh. I can immediately see the advantage of wood over metal in the winter months.

Asher

Paul Ewins

30-Nov-2011, 05:12

Where are the pictures that go with all these wonderful home made 6x12 cameras. There's such a lot of imagination and resourcefulness in making the cameras. So we'd love to see the results of all this work!

Asher

I think I've posted this before - my rather agricultural Kodak 6x14 with 90/6.8 Angulon.
http://www.paulewins.com/old_site/resources/3a_panoramic.htm

I've also hacked a Holga 6x12 pinhole to add a 65/8 Super Angulon. I've made several attempts to build a lever wind 6x14 so I an avoid counting numbers through a ruby window but haven't quite cracked it yet.

Steve Smith

30-Nov-2011, 05:30

Steve, What's your CNC machine?

It's a two head Excellon machine with a 600 x 450mm cutting area on each side. We originally bought it to drill and route printed circuit boards (which is what it was designed for) but we don't make our own PCBs now. It now gets used to make test jigs and assembly jigs - mainly out of PVC, nylon and Perspex sheet up to 9mm thick.

I learned to use it a few years ago knowing full well its potential to make items not for work use or 'training pieces' as I call them!!

This is one of the most beautifully crafted mods I've seen.

Thank you.

How good is your calibration of your cone

I'm not sure what you mean by this. If you mean how does the distance scale on the focus ring match up to reality, it is correct at infinity but not shorter. I do have a file somewhere which I can print out and stick in place for more accuracy but in reality, there is such a huge depth of field, even wide open at f8 that it doesn't need to be very accurate. I know where on the scale hyperfocal distance is for f16 and I tend to keep it there. I originally was intending to place the lens at hyperfocal anyway and not worry about focusing.

what does it weigh.

According to my not very accurate kitchen scales, about 3lb or 1.4kg.

Some pictures taken with the camera: http://jalbum.net/en/browse/user/album/979137/

Steve.

Steve Smith

30-Nov-2011, 05:43

Asher Kelman

30-Nov-2011, 11:36

And here is a picture of the camera completed with its matching oak back. When the web page was made I only had a temporary grey PVC back for it. I have also put the viewfinder in a better enclosure.

Steve,

I love your work and the pictures make it really worthwhile. You should post some in this thread!

Asher

Asher Kelman

30-Nov-2011, 11:37

I think I've posted this before - my rather agricultural Kodak 6x14 with 90/6.8 Angulon.
http://www.paulewins.com/old_site/resources/3a_panoramic.htm

Paul,

That's impressive and very deserving for a camera that's languishing unattended! Are you using it now? Any pics to show? The fun red wire on the spool area makes it look really Rube Goldbergish, as if you have added some nerdy new function.

Asher

Paul Ewins

30-Nov-2011, 23:45

Asher - a couple of old shots from Orkney and the Highlands (around 2005). I had trouble with the winding mechanism jamming and then breaking (hence the red wire and rubber solution) and getting precise focus is difficult as the camera isn't the most rigid thing on earth. I'm heading off to NZ for a week in January so I might beef it up a bit before then. As you can see there is a bit of vignetting happening in the corners but otherwise the old Angulon isn't doing too bad a job.

http://www.paulewins.com/old_site/resources/photos/cows.jpg

http://www.paulewins.com/old_site/resources/photos/ring_of_brodgar.jpg

Asher Kelman

1-Dec-2011, 01:18

Paul,

What a rich delight! These work for as well as a shot of rare malt Scotch! vignetting? If there's non there, I add it! There's no reason to have even illumination, it's just an obsession of lens collectors! It's only really important when stitching images or doing scientific work.

I love both the pictures and at first I thought this has to be 8x10 and then I remembered. You know we see a lot of Fotoman cameras advertised but hardly ever any pictures. It's a treat to see your work. I hope you'll share some more!

Asher