Some thoughts on the design of a lightweight 4x5

[Neil Barnes]

Well, got picture out of it - but I think I may (!) still have a light leakage issue...

Neil

[Neil Barnes]

There's a wide variety of different T-nuts - tripod bushes available from McMaster Carr http://www.mcmaster.com/ - Very inexpensive. I also need 3 or 4 along with rack & pinion parts for a geared trackbed and they have a good selection.

Ian

Found these, in the UK, Ian - though they don't seem to do screw-in tripod bushes except in 1/4. And again, they're UNC, not Whitworth. https://www.easupplies.com/EA-SUPPLIES- ... fa28hb.htm

Neil

[Neil Barnes]

Ah, that's more like it. Spraying the inside of the bellows black stops a lot of internal reflection. The image isn't as sharp as I had hoped, but that could be (a) ancient lens (1940s Wollensak 5x7 Extreme Wide Angle Series IIIa, 4-5/16" f12.5 on a rather tired Betax shutter), or (b) difficulty of focusing on my lovingly hand-crafted plastic ground 'glass'.

The picture's boring, but it's raining so I'm not going anywhere past the end of the garden today!

Neil

[Neil Barnes]

Another from the proto, this time developed in a caffenol variant I'm playing with...

0862.jpeg (78.6 KiB) Viewed 8049 times

[Andrew Plume]

Hi Neil

I haven't been through all of the replies to your post but I can say that there's a wealth of info re LF camera construction over on The Large Format Photography Forum

regards

andrew

[Robert J Fallis]

That caffenol is looking nice Neil,. As soon as I get my darkroom set up, I'm going to try some with paper negs., I've some old Agfa 10x8 here which can be the first victim

regards
bob

[Andrew Plume]

Hi Neil

and following our recent chat, I've just reacquainted myself with your own build - it's looking very lovely

regards

andrew

[Andrew Plume]

I'm seventy odd years old., and have this problem of camera pounds, this is my solution to the problem, and it will fit on a light tripod. it has no movements, and focus is by the front element of the lens a 10.5 cm Kodak, this on the 5x4 format gives a wide angle view. in order to check the focus the ground glass is fitted in a modified film holder. For close up work I intend to use old fashioned close up lens. but have not bought these yet..I did use the body as a point and shoot, and a pinhole..I have not yet fully tested the camera as I like to use paper negatives, and I haven't got a darkroom working as yet, to cut them



Bob

Hi Robert

I'm catching up with this thread and have had a look at your self build here (note to the mod's I'm copying this over as the initial post was some time ago)

looks great, perhaps based on the Bostick & Sullivan 'Hobo' or something similar?

regards

andrew

[Robert J Fallis]

hi andrew,
its just based on two boxes made with 2mm ply and 5mm board,
one box fits to a 5x4 dark slide and the smaller box slides inside. so you can make a rough
focus, then it's fastened and final adjustment is made with the lens focus.
I made a focus screen by replacing the centre of a dark slide with some ground glass,
and the tape makes up for my lack of wood working skills

bob

[Neil Barnes]

...my lack of wood working skills

I just hope that Andrew didn't take any pictures of the box I knocked together to send him some lenses...

I'm researching carbon fibre moulding; debating doing the major parts that way rather than messing around with two-pack adhesives and sheet carbon fibre. Could be easier; will certainly be more rigid and repeatable that way.

Neil

[Susie Frith]

How wrong can one be?!

While up in the loft, I dug out my Sanderson 5x4 Hand and stand camera, as it is about the lightest LF camera I own. To me, there is nothing of it. Very small, amazingly light, I thought I had your answer: a modern version of this.

Downstairs in the kitchen I popped it onto the scales, including the 135mm/4.5 Trioplan lens, and ground glass.

1500 grammes! Three times your target!

Oh well, back to the drawing board! Of course, in carbon fibre and titanium it would be lighter, but then out goes your £500 limit too.

Susie

[Neil Barnes]

Indeed; when I tried my proto made from aircraft grade birch ply and beech it's pretty good - but could be better!

My Sanderson is also heavier than it feels, if that makes sense. Of course, most modern lenses are also a lot heavier than their vintage cousins. (Of which - I had a major shock discovering that SLR cameras I grew up with are now considered 'vintage' on the bay...)

Neil

[Susie Frith]

Hi Neil,

I read with interest some of your recent comments about your intended use of the camera. A few years ago I was chatting to Paula Pell-Johnson who took over the Linhof agents from her father, about designing an English camera. This was about the time that Gandolfi was starting to dissapear, and before the Chinese started to appear!

After a lot of preliminary design work, I came to the conclusion that for me, I would be re-inventing the Technika! However along the way I came across all sorts of ingenious ideas from the latter half of the nineteenth century (I used to have a pass for the vault at the patent office!).

The major problem in design is to make a folding/compact camera that will do everything. This is what is needed to sell cameras. Too many folk think they need full adjustments on both front and back. However, as you mentioned above, if one really does need to use super wide-angle lenses and excessive adjustments, then use a monorail - that is what they are for! In the everyday landscape, if there are more than two principal planes of focus then adjustments won't help and one may as well use a box camera. The much sort-after Zeiss Universal Jewels A and B that Adams used (9x12 and 13x18) have front rise, cross and tilt (no swing) and back tilt. But then he was using them for landscape work and with modest lens size.

There was an interesting patent taken out in about 1896 by Rudolf Gotz (I think) in which the camera back just slid along and clamped to the bed for rough focusing. The front standard located on studs, with the normal front focusing slide doing the work there with a rack and pinion. The front provided rise and base tilt, the back provided base tilt and a small amount of swing. However the main point of the patent was that when it folded, the back was slid to the front of the bed, the front standard un-plugged and the whole thing tilted backwards lying flat on the bed, thus protecting the ground glass, but not the way a tailboard camera does it. The front of the lens was thus left out in the open, but protected with a lens cap, but it didn't need to be detached from the camera. Now, most of the components could be machined from flat or [ shaped CF, with the metal parts laser or water cut from thin sheet titanium. Mmmmmm! Of course it would only appeal to those who thought that camera design should follow your ideas and reqirements, but then you might be able to get ebony tinted CF!

If you need any help with prototype machining let me know.

Susie

[Neil Barnes]

A very kind offer, Susie - you may have access to better machining than I have!

The issue with casting/moulding CF is that you need accurately made bucks to make the moulds, including a good surface finish, and that costs expensive machinist time... the good news is that many of the parts can be made from flat sheet (well, strictly, *all* of the parts!) which has the advantage of repeatability. Unfortunately, there are a couple of bits that do require a good mould to be efficient and they're going to have to be made by hand. The front yoke is exercising my brain currently; I'm trying to see if it can be done with a single-part mould - I'm not sure yet.

At least there don't appear to be any bits yet that require a good surface on both sides...

The design is changing all the time as I tweak with it and play with the prototype: currently it looks as if a rear standard with tilt is easier to do than one without - or at least, not significantly more expensive. Current parts list, back to front:

- focus screen
- back - can be mounted portrait or landscape
- rear standard
- base plate with focus rack
- focus traveller
- yoke
- front standard
- lens plate

Aiming for rear tilt, front tilt, rise, and swing.

At least there aren't any valid patents on box cameras any longer!

Neil