4x5 reducing holder possible?

[Kevin Kehler]

I have just got into large format photography, having purchased a 5x7 Korona from Colin (Photobiz). I like the size and ratio of the 5x7 but am not really happy about the cost of film. In Canada, 25 pack of FP4+ is $65; same film in US, $45-49 with Adorama wanting $37 (and $35 to ship to Canada). 25 pack of 4x5 FP4+, $35 dollars in Canada. The Canadian dollar is at about .95 cents, so 5% difference due to currency valuations. I don't feel like blowing $2.10 a picture learning to use a large format camera and would much rather spend $1.20 a picture while learning (I do want to use the full 5x7 the majority of the time in the long run).

Is it possible to construct a device to fit in the 5x7 back but which will hold a 4x5 holder? I have attached a rough diagram of my idea (brown being the device, red being the holder and silver for the darkslide). You would insert the 4x5 into the holder and then insert the holder into the camera back. Key issues would including ensuring centering on ground glass and withdrawing/inserting the dark slide (it is recessed a couple of cms).

Am I just reinventing the wheel? Is there an easier way to make a reducing back (most people are going from 8x10 to 4x5, no used 5x7 to 4x5 backs I can find)? Or is it fairly simple to construct your own reduction?

[redrockcoulee]

There are 4X5 reducing backs for most of the older 5X7 cameras. I have one for my Seneca that was home made but I have seen a 5X7 Korona with a 4X5 back. You could also buy Arista Edu 5X7 film from Freestyle and I believe that when I got my order in from them there was only GST added to the shipment.
The home made reducing back that I do have is simply a back made of plywood with the 4X5 back from an old Crown/Speed Graphic screwed on. I have bought a 8X10 to 5X7 reducing back with the plans on converting it to a whole plate to 5X7 back. It would probably be more exact to find an old 4X5 back from a "dead" camera or a 8X10 to 4X5 back and modify them then to create what you described. At least it is another option to think about.

[pdexposures]

If you really wanted to get shooting right away while you looked around for an actual reducer you could always just put the 4x5 film into the 5x7 holders. Just be sure to turn them 90 degrees lol.

[jnanian]

toho in japan makes one.
for 8x10 to 5x7
and 5x7 to 4x5

http://www.toho-machine.co.jp/Reducing.htm

[John Koehrer]

Reducing backs were very common for just about any brand of camera. As mentioned above the plywood & 4X5 back works & might be quicker.
Take a look at the back you have &copy the light trap. 1/4" p;y is cheap & easy to cut with a utility knife.

[steven_e007]

In days gone buy you could buy cardboard inserts to fit into plate holders to accommodate plates that were smaller than the holders. I have a set that let's me put 2 1/2 X 3 1/2 " plates into quarter plate holders.
The problem with film holders is that they are too thin, with too little clearance for cardboard inserts. Instead, I have made ones from polystyrene plastic card, which is thinner and stiffer. You can but this very cheaply from model suppliers or on eBay. You cut a sheet the same size as the film, then cut a square "U" shape which you glue on the top to hold the smaller film. Finally, glue some 'lips' on top of that to hold the sheet of film. Just 5 minutes with a modelling knife and a tube of polystyrene cement. Slot the plastic holder into the film holder then load in the normal way. I've made a few of these and they do work. The very simple arrangement I have described would put the registration out by a fraction - unlikely to be a big problem unless you are using big aperture - but with a bit of thought you could make a slightly more complex version (10 minutes?) that would put the film flat against the back of the holder...

[Ian Grant]

Steve, I'm doing similar but with a different approach, making an adaptor to fit a Graflex 6x7 back (just arrived from WadeD) into the my Quarter plate camera.

Ian