Sinar F (F1/F2) camera and Sinar P 5x7 changing kit

[vitality]

In case if you need to have 5x7 "F" series camera (it might be weight and size problem of P series, or simply the price), you face a problem to find 5x7 "F" rear standard, however there is quite a lot offers for Sinar P 5x7 kit. So I decided to give a try and make some adapter for my F2 rear standard, so it could accept those widely available P series kits.

And straight away remark: I was trying to find info in internet, may be somebody have done something like this before, but I could not. Only info what I found was "it cannot be attached, you need P rear barrier. If information for this kind of modification is widely available in internet, and I was stupid enough not to find it, sorry - my bad I'm not trying to be a "smart guy" (look I found solution, world is safe now), just passing info to public, may be it will be usefull to someone? or may be somebody will advise how to make it easier and better.

And straight away a picture of final result:



What we need:
-20x20mm wood (smaller size might work, however I choosed this one, to be on safe side, in case I need to screw in some extra screws, so it doesn't crack)
-1 big screw (20-25mm long, and diameter of "head" just to fit inside attachment hole of frame)
-100x15mm metal plate (you can see on picture how it looks like, I'm not sure what is made for, but you can easily find those in construction shops)
-4 small screws (15-20mm long) (2x to attach vertical plate, 2x for "vertical position adjustment")
-4 a bit longer screws.

Take wooden stick and cut it with size of 5x7 frame (approx 23cm long).
Measure approximate position of attachment hole of frame, mark it on the wood - that's gonna be the place where "big" screw goes. Screw it in, attach frame - just to see is it in good place.


You can see a big "silver screw" on picture, thats the screw to which we will attach our 5x7 frame.


At this moment everything is clumpsy + there is small ammount of metal which sticks out of frame, and doesn't allow frame to stay vertically. So mark a place where it is, and take a knife to cut small hole for it (I took paper knife, was enough to make a small cut).


Here is that small cut in wood

[vitality]

Again, try to attach frame and see how it works.
Now lets screw 2 small screws on top of big one (put each few cm away). Those we need to make final adjustment for absolutely vertical position of our frame. First I screwed them fully in, later I was just uncrewing them a little bit, to see how it changes position of frame (for easier evaluating, unscrew your 4x5 frame from rear standard and just put it on top of it, compare, does it look paralel with front standard (slide it close to rear one, so it will be easier to see)).


You can see those 2 "brass color" screws placed a bit higher "big" one


Try to srew in/out "big" screw, and monitor how does it affect connection between your adapter and frame (if you have it to much out, it will be clumpsy, if you have it to much in, it will not hold, if you have it in right position, frame will be attached firmly). You got approximately vertical position and your frame is attached firmly, lets attach the "plate".

You have your frame attached to wooden adapter, so simply slide plate fully inside frame (that long cut in frame you have*) and screw it (we need it so frame doesnt rotate around "big" screw).


Picture shows where it should slide in. Actually, when making 1st measurment (where big screw goes), you need to keep in mind, that side of your wooden stick shoulb be in center of that cut in frame (hope it is possible to understand what I mean).


Evaluate result... If you are happy, take rear standard, unscrew 4x5 frame from it (well we have done it before), and attach new adapter (use 2 screws in the beginig, if you are out of position, its easier to reattach). Put everything on "0", slide front standard next to rear one, and make approx mark where adapter goes (with 5x7 frame attached will be quite easy to find a place where it goes).


Here is 2 screws attaching adapter to rear standard


Well that is it. I managed to do it in 1h time (i'm not a construction guy, and usually I have screwdriver in my hands 1-2 times a year, so it should be easy to do for everybody), without any extra fine measurment (just because I don't think that 1mm right/left of center, or 1 degree out of paralel position will make much difference, anyway you control it during taking picture, however it is good to place it as precise (in the middle, and paralel to other standrds) as you can).

Generally it stays firm, without play (I get play from rise/fall adjustment of standard, not from adapter).

Dissadvantage is, that there is not much left for rise of front stndard (approx 2cm). That can be corrected by making a spacer between frame and adjustment part of front standard, or by choosing thinner wood for adapter (1cm thick will add 1cm to front standard rise).

* the older adapter have a long cut, however new adapter have 2 small cuts, you need to keep in mind. Or you take 1 plate and sand it in the middle, or choose 2 separate small paltes.


New and old 5x7 frames, you can see difference in cuts.


When you attach frame to P barrier - attachment knob is on the righ side from you (if you look from the back), however I chosed to put it on left side. 1st of all, plate will be not sticking out towards you, it will be under bellows (mostly visual appearance). 2nd less knobs on right side (there is already focusing and rise fall). 3rd there is 7cm to go left and only 3 to go right, in case to attach 8x10 frame, we will need to slide it more left, and and 7cm will be enough of afjustment, however if we construct it on right side, 3cm would be not enough. I didn't try to attach 8x10 frame, I simply don't have it yet. Migh be it will never work, but I decided to have this possibility in case it will work. Also, when attaching 8x10 frame it will be not enough of rise for front standard, to put lens in center position, but this is another story, and it could be solved with spacer.

I did only 1, and I cannot promise that it will work for you as well, but I managed to make it. Maybe I just was lucky that everything came to it's place (center, vertical and without play) from 1st time...

Sorry for my bad english, hope it is possible to understand what I wrote, and I hope I pointed out all main aspects, when constructing adapter. If you don't understand something (starting why should somebody do such a thing, and ending with choosing screws), please ask, Ill try to give more info on that point.

Wow, a lot af letters. Hope it will be useful to someone.