PDA

View Full Version : Looking for a lens flange..



Topsy
6-Oct-2017, 06:05
Hello,

I recently bought a lens for a camera project on ebay and am looking for a fitting lens flange.
I've seen various alternative methods mounting methods but a proper flange would obviously be nice to have and would look best.

The lens is a PACSA (Photographic Artists Co-operative Supply Assiciation (http://www.earlyphotography.co.uk/site/companies3.htmlhttp://)) Rapid Landscape 539 (or 538?).

https://i.imgur.com/jHFlc7Pl.jpg
(excuse me for the really bad photo)

The thread diameter is, at it thickest spot (it tapers?) 40.8mm, tpi is, estimated 31.75.
Sadly camera fairs aren't a thing here as far as I'm aware. Maybe it's better like that for my wallet! :o

Does anyone know what the correct size would be?

I know I could get it machined but I doubt that'd be economical in Switzerland.


Another question is.. The seller didn't know what this is and sent it with the lens.
I assume this is not anything to do with any kind of camera/lens?

https://i.imgur.com/1iC8cJ2l.jpg


Many thanks,
Topsy

Steven Tribe
6-Oct-2017, 11:13
Dear Topsy,
I remember seeing this listing - there is no obvious function for these metal pieces in connection with the Landscape lens!

The PACSA organisation just bought in from many places and engraved their lengthy name on items. I believe the real maker was Wray.

Getting flanges made is expensive and difficult evrywhere. The machinist has to set up a lathe, find suitable aluminium or brass stock and use quite a lot pf time.

When this was made, most UK had standardised threads and dimension. It looks to be in the normal range of diameters. If you measure the thread diameter (Inches not metric!) you can post a wanted add here in a hidden thread which becomes open to you in about a month after joining.

I reckon your flange should have 1 5/8" thread. Many of us do have extra flanges.

For sale and wanted is not allowed outside the 2 commercial threads which you can't use for a month. Don't be angry if the Mods delete your posting.

I have exactly the same lens, just a lot larger (3" thread), but with no engraving. The tapered thread is due to wear or adaption to the wrong thread!

Topsy
6-Oct-2017, 18:23
Dear Topsy,
I remember seeing this listing - there is no obvious function for these metal pieces in connection with the Landscape lens!

The PACSA organisation just bought in from many places and engraved their lengthy name on items. I believe the real maker was Wray.

Getting flanges made is expensive and difficult evrywhere. The machinist has to set up a lathe, find suitable aluminium or brass stock and use quite a lot pf time.

When this was made, most UK had standardised threads and dimension. It looks to be in the normal range of diameters. If you measure the thread diameter (Inches not metric!) you can post a wanted add here in a hidden thread which becomes open to you in about a month after joining.

I reckon your flange should have 1 5/8" thread. Many of us do have extra flanges.

For sale and wanted is not allowed outside the 2 commercial threads which you can't use for a month. Don't be angry if the Mods delete your posting.

I have exactly the same lens, just a lot larger (3" thread), but with no engraving. The tapered thread is due to wear or adaption to the wrong thread!

Thanks for your reply Steven,

Yes, I would have been surprised if someone would have told me that it belongs to the lens! But I thought maybe, just maybe, it might be something off some camera. I did wonder the other day if it belonged to a furniture leg though.
I've bought the lens to experiment with and eventually build myself a 4x5, but don't actually have any hands on experience with LF cameras yet. :o

I'd actually have a lathe myself, but annoyingly it can't do any threading (well, it can, with a tap & die)..

Regarding the thread standard.. The last time I needed a screw for a lens (pinion screw for a no-name magic lantern Petzval type) I could not find anything that was exactly the right thread, so I really hope this one will be a bit easier!

And you must be right, it does look a lot like a Wray! If the thread normally isn't tapered it sounds like the flange had been lost a long time ago..

I must say, I totally missed the commercial threads.. I knew there was a reason I should have signed up here earlier! ;)
Edited my original post now.

Many thanks!
Geoffrey

LabRat
6-Oct-2017, 19:23
It is fortunate that the barrel has a seat larger than the threaded area below it, because there is a good solution if the flange is missing...

You can bore out a lensboard where the hole is just slightly larger than the threads, and draw out a hole circle that is larger than the seat, and lay out space for 3 or 4 bolt holes on the lensboard that have spacers that allow them to fit close (barely touching) around the lens barrel, but allow a washer or custom block to go over the top of the bolts and hold down the seat area... (These retain the lens from falling off the board...) There can be spacer tubes with washers, nuts with washers, or a carved block that fits into the radius of the seat... This works well with several barrel lenses I have mounted that didn't have a flange... (Think of it like the lugs that hold your tire rim to your car, but just hold the outside edge of the lens to the board...)

One thing to note is if the internal F/S area behind the lensboard has room inside for the heads of the bolts that then extend to the front of board, but you can also countersink the heads for more clearance inside...

Good Luck!!!

Steve K

Steven Tribe
7-Oct-2017, 01:08
You can't even see the two commercial threads exist here until the 4 weeks have passed!

These conical landscape meniscus lenses are often a source of mistakes (decit sometimes?) by listers and auction houses as they bear a superficial likeness to some very early designs. Generallly speaking, the early ones have insert washer stops rather than a Waterhouse stop arrangement at the front and use thinning brass housing.

Here is my "Wray" along with some of the early offerings from Chevalier.

Jimi
7-Oct-2017, 02:07
Upside down is the way to go, Steven. :)

I've been doing the drill out excercise on a lens board, and I think it works fine. Another idea would be to find a school environment where they have machinery and someone could make a school project out of making a flange.

3D printing? I suppose that doesn't work. Yet.

Steven Tribe
7-Oct-2017, 04:13
Actually, on my ipad the thumbnail becomes the correct way up when I "enlarge"!

I have a "to do" project concerned with using teflon tape pressed into the thread (Used in joining/sealing threads in plumbing) with re-enforced plastic.

LabRat
7-Oct-2017, 06:13
Actually, on my ipad the thumbnail becomes the correct way up when I "enlarge"!

I have a "to do" project concerned with using teflon tape pressed into the thread (Used in joining/sealing threads in plumbing) with re-enforced plastic.

Hot glue on the outside of the threads in a snug fitting hole will also work for not so heavy lenses... Also easily removed from brass/metals later... (For testing purposes...)

The image looks OK to me... Just like a GG!!! :-)

Steve K

Topsy
8-Oct-2017, 19:20
It is fortunate that the barrel has a seat larger than the threaded area below it, because there is a good solution if the flange is missing...

You can bore out a lensboard where the hole is just slightly larger than the threads, and draw out a hole circle that is larger than the seat, and lay out space for 3 or 4 bolt holes on the lensboard that have spacers that allow them to fit close (barely touching) around the lens barrel, but allow a washer or custom block to go over the top of the bolts and hold down the seat area... (These retain the lens from falling off the board...) There can be spacer tubes with washers, nuts with washers, or a carved block that fits into the radius of the seat... This works well with several barrel lenses I have mounted that didn't have a flange... (Think of it like the lugs that hold your tire rim to your car, but just hold the outside edge of the lens to the board...)

One thing to note is if the internal F/S area behind the lensboard has room inside for the heads of the bolts that then extend to the front of board, but you can also countersink the heads for more clearance inside...

Good Luck!!!

Steve K

This probably what I'll do for the time being, though for long term I'd rather like to find a flange as it just looks much more complete if you know what I mean! :)



You can't even see the two commercial threads exist here until the 4 weeks have passed!

These conical landscape meniscus lenses are often a source of mistakes (decit sometimes?) by listers and auction houses as they bear a superficial likeness to some very early designs. Generallly speaking, the early ones have insert washer stops rather than a Waterhouse stop arrangement at the front and use thinning brass housing.

Here is my "Wray" along with some of the early offerings from Chevalier.

Yep, there's definitely some likeness there, but the size definitely isn't ;)


Upside down is the way to go, Steven. :)

I've been doing the drill out excercise on a lens board, and I think it works fine. Another idea would be to find a school environment where they have machinery and someone could make a school project out of making a flange.

3D printing? I suppose that doesn't work. Yet.

That's a good idea, might as well ask!
And yeah, I wouldn't fancy 3D printing anything to hold a lens, though it might work. Not worth the risk to me though!

tonyowen
9-Oct-2017, 06:58
eBay UK supplier old_cam lists lot of imperial lens flanges
To me his/her prices are a bit high - but he/she seems to have the market cornered with those items.
I have no relationship with him/her

regards
Tony

Drew Bedo
18-Oct-2017, 19:01
This may not help much but:

There are three basic flange types.

1. Too large.
2. Too small.
3. Wrong thread.

MMELVIS
19-Oct-2017, 17:31
Do a search on retaining rings or V-Band Clamps/Couplings or T-Bolt Band Clamps or Machined Flanges for use without Gaskets on google. I have used them to hold a lens on to a lens board.