Polaroid RF to 6x9 with 90 mm lens ?

[Thomas78]

Hello,

I would like to have a folding MF (6x9) rangefinder which gives me the following advantages over a classical folders:

- NLQ (= near Leica (M) quality) Rangefinder
- a smaller focal length
- a more rigid lens mount

I think a Polaroid RF like the 110B or the 900 would be a good starting point with their nice RF and the ability to provide a rather rigid base for the lens.

So my idea is to convert the camera to rollfilm and mount a 90 mm lens on it to get a focal length which is simillar to a 40 mm lens on 24x36 mm.

This brings up the following questions:

- how to couple a smaller focal length with the rangefinder
- could the projected lines be altered with a new mask for a (more or less) correct framing
- which lens to use (wich will still enable to fold the camera)


What do you think about this idea?

 

[Sonnar Brian]

That is a major project because of the focal length change. The throw of the bellows will have to change, and the cam for the RF will have to change. The full-size Polaroids are set up for 114mm focal length. The smaller size Polaroid (Highlander model 80) does not have an RF. It's film size was closer to 120.

Somebody was thinking about the conversion.

http://www.youtube.com/watch?v=b6-0PmcXdjo

There are some 120 backs for Speed Graphics, and 90mm lenses exist for them. This would be an easier way to accomplish the goal.

 

[Roger Hicks]

How about a 'baby' Linhof?

Cheers,

R.

 

[FPjohn]

Century Graphic or as Roger suggests a 6x9 Linhof: The Tech 70 will give you the "NLQ" RF.

yours
FPJ

 

[DamenS]

Hi Brian,

Are you sure the rangefinder was set up for a 114mm focal length ? Do you know why they did that given the cameras came with a 127mm lens ?

 

[Thomas78]

Hi Brian,

Are you sure the rangefinder was set up for a 114mm focal length ? Do you know why they did that given the cameras came with a 127mm lens ?

As far as I know, 114mm was the focal length of the packfilm cameras. The rollfilm cameras have a focal length of 127 mm or 130 mm:

http://www.rwhirled.com/landlist/landdcam-pack.htm

 

[Sonnar Brian]

You are right- the 114mm RF was for the pack cameras. It has been a long tiem since I looked at a 110 with it's 127mm lens.

Either way, the RF would need a new cam.

 

[Thomas78]

You are right- the 114mm RF was for the pack cameras. It has been a long tiem since I looked at a 110 with it's 127mm lens.

Either way, the RF would need a new cam.

That is true - unless you are able to build and implement a gearing to adapt the rangefinder to the different focal length as it is done by the double helix system of the small format RF lenses (as LTM or M-Mount).

But modifying a RF for a different focal length seem to be to complicated.

Either accept the 127 mm (110B) or 130 mm (900) and use it as "light telephoto lenses" with 6x9 or just use it as a viewfinder camera which would bring us back to the polaroid highlander 80.

This approch could maybe give you a MF wide angle folder if you can find a lens which is small enought to fit under the "door" of the folding camera.

Do you know if it uses unit focusing or front element focusing?

 

[Particular]

How about a 'baby' Linhof?

Cheers,

R.

x2
Although while 6x7 rollex backs are seemingly everywhere, 6x9 backs are not. Nor are they cheap.
Perhaps the Technika 70 may be overkill for some, the view and rangefinder are great, with nice parallax adjusted frame lines. It is a definite step up from a folder. Does the O.P. have a weight limit?

 

[Roger Hicks]

x2
Although while 6x7 rollex backs are seemingly everywhere, 6x9 backs are not. Nor are they cheap.
Perhaps the Technika 70 may be overkill for some, the view and rangefinder are great, with nice parallax adjusted frame lines. It is a definite step up from a folder. Does the O.P. have a weight limit?

Parallax and frame size (for distance). Makes Leicas look quite crude. Then again, the RF module is about the size of a Leica...

Point taken about back availability. Frances has a Linhof/Alpa 6x9 for her Alpa 12 S/WA, but I actually prefer 6x7 (all I have for my Linhofs), especially in the Linhof 56x72mm format: a 3x enlargement is whole plate, all but indistinguishable from a contact print.

Cheers,

R.

 

[Thomas78]

x2
Although while 6x7 rollex backs are seemingly everywhere, 6x9 backs are not. Nor are they cheap.
Perhaps the Technika 70 may be overkill for some, the view and rangefinder are great, with nice parallax adjusted frame lines. It is a definite step up from a folder. Does the O.P. have a weight limit?

I would like to find a concept which weight 1500 g or less.

A Linhof Technika 70 or a Century Graphic are very fine cameras I suppose, but I think there are neither small nor light weight.

Parallax and frame size (for distance). Makes Leicas look quite crude. Then again, the RF module is about the size of a Leica...

The finder of the 110B also has both parallax and frame size correction but only for its standard 127 mm lens.

 

[Roger Hicks]

The finder of the 110B also has both parallax and frame size correction but only for its standard 127 mm lens.

Dear Thomas,

Gosh, I didn't know that. Thanks. Are you sure (and I'm not being funny, I genuinely don't know) that the lower/inner frame lines move? Because several Konicas move only the upper/outer frame lines, leaving the inner stationary, which is a good approximation but not in Linhof's class. As I say, this is an inquiry made from genuine ignorance, not an attempt to score points: I was initially fooled by Konica.

Cheers,

R.

 

[keytarjunkie]

To be honest, the polaroid roll film cameras make much better 4x5-format shooters. Without serious modifications to the inside, the light basically covers the entire 4x5 frame from the 127mm lens.

I've been shooting with my modified 900/160 for a few months and still have to calibrate the rangefinder, it's nice but very heavy. My pentax 6x7 feels lighter. It's also freakin huge! I think there are better options out there for modifying to take roll film (but I don't really know what they are).

 

[Thomas78]

Dear Thomas,

Gosh, I didn't know that. Thanks. Are you sure (and I'm not being funny, I genuinely don't know) that the lower/inner frame lines move? Because several Konicas move only the upper/outer frame lines, leaving the inner stationary, which is a good approximation but not in Linhof's class. As I say, this is an inquiry made from genuine ignorance, not an attempt to score points: I was initially fooled by Konica.

Cheers,

R.

Now that your mentioning this point, I think that the Polaroid-System ist like the Konica, this menas that only the upper/outer frame lines move, while the inner frame lines are stationary.

Dante Stellar thinks that the Rolaroid 110B rangefinder was made after the Konica pattern:

[FONT=Arial, Helvetica, sans-serif]the 1960 model 110B has two changes from the 110A. The first is that the rangefinder and viewfinder are combined, with field-corrected framelines that shrink as you get closer. RF image is a yellow trapezoid (clever) on a bluish field. [...] My personal suspicion is that the finder was made under license from Konica, which had just invented this type of finder with the Konica IIIA and the Pearl IV.[/FONT]

http://www.dantestella.com/technical/polaroid.html

To be honest, the polaroid roll film cameras make much better 4x5-format shooters. Without serious modifications to the inside, the light basically covers the entire 4x5 frame from the 127mm lens.

Yes, you are right, the 127 mm lens and the camera body seem to be a very good match for 4x5 and I am serious considering to get one (or a Graflex) as my first LF camera.

I've been shooting with my modified 900/160 for a few months and still have to calibrate the rangefinder, it's nice but very heavy. My pentax 6x7 feels lighter. It's also freakin huge! I think there are better options out there for modifying to take roll film (but I don't really know what they are).

I already have a 110B which is converted to the type 100 pack film and like this camera (and its RF) very much but should use it more often - i think I will try the ASA 3000 film from fuji for available light. (And this started the idea of my original post here)

 

[planetjoe]

(caveat: I am an unapologetic Polaroid admirer/collector, but haven't yet accomplished this particular modification)

The general expectation in modifying the Polaroid rollfilm bodies (which are well-built, beautiful cameras without a current purpose) to shoot 4x5 is that the film plane must be moved rearward anywhere from 3/8" to 1" to expand the FOV to fill the format. Once that is accomplished, infinity focus must be re-set, which is usually straightforward (drill, rivet and/or bolts).

Then, naturally, the RF cam is technically out-of-spec for focusing the native 127mm lens (or anything else you could swap in) to close distances. Some have used 135mm lenses in the original lens' place, instead of resetting infinity - if you measure things out correctly, this would work. But then the RF is still out of spec, having been profiled for the 127mm focus curve.

There are some folks on the web who have stated that the RF of the 110a/b/900 is suitable for focusing in these situations for large DOF - which it probably is, in fact. But it's obvious that the limitation of these mods is the RF cam, which is a fiddly thing to re-cut.

I've seen some fleeting suggestions on the web that one could technically profile a new cam, but that would take a little thinking. I do not think the leading Pola-mod craftspersons do this.


Cheers,
--joe.

 

[MaxElmar]

... or a Century Graphic are very fine cameras I suppose, but I think there are neither small nor light weight.

The Century (not the Speed or the Crown) Graphic may meet your needs as it's a plastic "mahogonite" body with lightweight fittings. It folds up quite small. A nice range of backs up to 6x9 are available. The RF is user adjustable to many different lenses - I have an ex-Mamiya press 65/6.8 on mine right now.

It's nice to have a quality ground-glass focusing panel - you can even pretend it's a mini view camera with a bit of movement. Or you can pretend it's a funky Super Ikonta with interchangeable lenses and backs.

 

[ruby.monkey]

Century Graphic or as Roger suggests a 6x9 Linhof: The Tech 70 will give you the "NLQ" RF.

yours
FPJ

... and a hernia. Not to mention that the rollfilm back's rearward protrusion makes it awkward to sight through the viewfinder.

Is there a 6x9 back for the Technika 70? I've only ever seen 6x7.

 

[sevo]

Is there a 6x9 back for the Technika 70? I've only ever seen 6x7.

It was intended to popularize 6x7, and that is the only format it will do. True 72mm of 6x7 though.

 

[Roger Hicks]

Why not put a 6x12 back on a Polaroid? At that point, 114mm is slightly wide...

Cheers,

R.

 

[Matus]

I have seen many threads over at LFF about the Polaroid conversions and was (am) interested about 6x12 conversions. My understanding is that that is no real problem to do, but the camera is just very large for "just" 6x12. As was mentioned above - 4x5 conversions make more sense.

One should also note that many of these conversions are often sold by their new owners ... (think of X100).

There are people doing these conversions and you can indeed have the camera modified for focal length of choice (though only compact lenses can be folded without removing the front element).

I am wondering whether it would be feasible to butcher a Bessa III (or probably 2 of them) to make a 6x9 or 6x12 camera. But I guess it would be pricey ... 😉