Tachihara 10x8" + Sinar Copal shutter modification

[John Austin]

The purpose of this modification is to allow the use of my Sinar Copal Shutter on my Tachihara 10x8" camera. This modification serves two functions, firstly it allows barrel mounted lenses to be used in the field and to bypass the use of the shutters in my antiquated 10x8" lens set with the accurate and consistent Sinar Copal Shutter. Crucial to the modification is the ability to to return the camera to a bog standard Tackyhara 10x8"



For more please visit Dead Link Removed

 

[LJH]

John,

How have you attached the shutter behind the front standard? (Please excuse me if Tachi's take Sinar bellows; I've never used one).

 

[John Austin]

Hello LJH

The Tachi's bellows are glued to the rear of the front standard frame, but are of poor quality material so I have decided to replace them

As the camera takes Sinar sized lens boards the frame was the riight size to have an extension frame the same depth as a Sinar lens board fitted to the rear of the front standard to take the front of the Sinar Copal Shutter - All that was needed was a plate at the bottom to hold the bottom of the shutter and a sliding lock at the top, a simple reversal of the front arrangement on the Tacky front frame - I got hold of a set of dead Sinar bellows and removed the frame from them, which I then glued to the front of the bellows

I will not remove the original bellows until I have used the camera in this format for a few days to check everything out, but one joyous discovery is that the camera will fold flat with the Sinar Shutter mounted

A crucial aspect of the modification is that I can return the camera to its original state apart from having nice new bellows, so the metal fittings I have replaced are stored should I ever decide to sell the camera - It would then be sold with the modifications reversed but the new bits included

I purchased the camera from the Queensland importer as a run-out deal which Elle Young at Gold Street Studios advertised - However being stored in Brisbane's tropic air the bellows had sweated while being stored flat, and the surface finish pulled apart when the bellows were opened - I thought they were stuck together forever, but I managed to open them ridge by ridge, with lots of surface peeling off



I hope the pix help - For more information please visit Dead Link Removed

 

[John Austin]

Here is the whole text of my website post

5th February 2012
Sinar Copal Shutter to Tachihara 10x8" Modification

The purpose of this modification is to allow the use of my Sinar Copal Shutter on my Tachihara 10x8" camera. This modification serves two functions, firstly it allows barrel mounted lenses to be used in the field and to bypass the use of the shutters in my antiquated 10x8" lens set with the accurate and consistent Sinar Copal Shutter. Crucial to the modification is the ability to to return the camera to a bog standard Tackyhara

A firm decision was made to mount Sinar Copal Shutter behind the Tackyhara front standard. Doing it this way keeps the rear lens element clear of the shutter, holds the centre of gravity closer to the front standard and looks better. This mounting has the disadvantage that it only allows a 21mm lens drop, but a greater drop can be achieved by tilting the standards back. A good surprise is that the camera will fold flat comfortably with the shutter mounted, this is a real bonus for quick setting up
Tachihara with Sinar Copal Shutter

The very tacky Tackyhara bellows are being kept for the time being as the wood they are glued to on the rear standard is thin and I am not sure I can remove them without splitting the wood, unless I cut the bellows material away and scrape the last bits off the standard. The bellows are bad as the camera was purchased from the Australian importer where it was stored in Brisbane's tropic air where the bellows sweated to a solid mass and had to be pried apart fold by fold, with a lot of surface finish peeling off in the process

Gluing the Sinar bellows end frame was simple and is acceptable for the time being, but I will do a light leak test as soon and the camera is reassembled and reinforce with good bellows repair tape. I have a set of Chinese nylon Sinar 10x8" fitting bellows ready to fit to the camera as soon as the Tacky bellows fray. For the Sinar bellows end frame I am indebited to Daniel Stone, LA

I have replaced the short and curly lens board clamp and slider with new ones fashioned from 1.6mm brass, 0.3mm thicker than I would have liked, but in my tool box so it was used. The top sliders are from the rear frame of a dead Speed Graphic International Back and these have guided the design of my own brass bottom fittings. The SG sliders are chromium plated brass and I very briefly considered filing the chromium off the front, but I have better things to do with my life. At first I hated the too shiny brass on the Tackyhara, but am now getting to not see it except when the sun reflects off it, but we are coming into the Southern Winter

Next job was to have a rebate professionally cut into the rear of the front standard frame to allow either the Tackyhara bellows or Sinar Shutter to be mounted onto the frame. However, Russell, the local cabinet maker, made the observation that the Tackyhara front standard frame's joints are poor quality and he suggested the addition of a new layer of jarrah to provide the depth for the front of the bellows or Sinar Copal Shutter. This has been done

Note, the Tachihara 10x8" was bought as an importer cut price run-out. It was not my first choice for a 10x8" field camera, but was cheap and cheerful and has the advantage I do not feel precious about it. However, I am starting to ignore the camera's design faults, like the split pinion on the rear focusing racks, a stupid idea. There are good points about this camera apart from the low price. It has a sturdy front standard that will support the heavy 36cm Voigtlander Heliar for the Naked Portraits and it has a superb focusing screen. Now to take it out and use it

 

[Steve Smith]

Looks good.

I don't know much (or anything) about these shutters. Where is the speed adjustment located and do they need cocking?


Steve.

 

[John Austin]

The shutter speed setting, from 1/60 to 8 full seconds, is on the arc at the top left of the shutter when viewed from the rear

It is self cocking with a cable for use on a Sinar, and soon the Tacki, for the insertion of a DDS to close the shutter down for exposure, however, this requires some energy, so it is important to support the rear standard at the opposite side to the DDS insertion, to push back a bit - In practice I use the lever on the shutter to close the shutter for use except with 5x4" where it seems to work very easily - There is no logic to this except perhaps to the size and friction of a 10x8" DDS

In the DB mounted lenses the aperture is set on the right side of the shutter from the camera back, unless you are working 1:1 with a long lens, then you need an arm extension

I have removed the aperture scale, with great care so as not to break the string, to enable it to fit withing the brass stays on the Tachi front standard

I am surprised every other manufacturer has not come up with a similar solution to consistent shutter speeds, poor Compur and Copal