Graflex 23-RH8-backs-Two versions

[michael_przewrocki2]

<p>http://www.glennview.com/vcamacc.htm<br />http://glennview.com/jpgs/vcamacc/filmholders/rollholders/23rh8/knob/big_2.jpg<br />he is showing two versions-both with knob which should be better than film-advance lever, the newer one with<br>

smaller window(whats its size?) and film-flattening rollers. he could have shown.<br />so the disadvantage is its smaller size. and the advantage on both is not only film-flattening but.<br />"These knob wind holders are more reliable than the lever advance holders because there is no return spring to break."<br />Asking since i have Graflex Graflok 4x5 divider back(sliding back) for graflok23-backs(RB67 etc)<br>

i can use graflex RB67/70 vaccum-back(vaccum as option when one has sucking bulb)<br>

NB: its only sucking on one side but i was told its perfect.<br>

So when buying one must ask the seller which size the window has. But which are both sizes?<br>

nominal is: 2.25X3.25" or 6X9cm 57.1 x 82,55mm<br />NB: Graflex RB67/70(mm) is: 56.8 x69mm. so 6x9 is impressively bigger. but only the "bad" one.<br />from the image i am calculating 75.4mm, approx. 7mm shorter. only 6mm larger than the mentioned 6x7.<br>

70mm-back<br>

NB: Graflex RH50(70mm)- which was told not to hold film as flat at the Mamyia-even without vaccum-takes both DP and UP/Double-and Unperforated 70mm film.<br>

We will make wooden adapter to mount 120/220-film-without paper into 70mm-cartridge. the should be offered 3D-printed made of metal. the 35-120-adapter made of plastic(now also in metal) produces residues. AND: dont ever use it in Kiev60-like cams. they will breake film-pressure-axis on left side. dont know which if the pentacon-six-mount cams are built the same way.<br>

Alternative to mentioned adaptation is using rotary-45-back for HB-V-backs getting 4 x 55mm-images. on ebay from china. i am unsure if they are flat enough, above all with for long-exposures. for planetary-work it had been proven: not flat enough. have read a lot about hasselblad zeiss 110/2.0-owners not getting enough sharpness.</p>

[dan_fromm2]

<p>Learn to feed yourself. Failing that, buy the wretched things, run film through them, and measure the areas exposed.</p>

<p>Modern (ones that use 120 film) roll holders made by Graflex Inc, predecessors and successors, have two major assemblies. Film carriage and shell.</p>

<p>Carriages came in two flavors, ignoring the gearing that controls how much film is advanced per shot. Knob wind and lever wind. The two are functionally equivalent and there's little basis for choice between them.</p>

<p>Shells for nominal 2.25" x 3.25" (6x9 is a terrible metric approximation to 2.25x3.25) come in two flavors. RH-8, with pin rollers and a 56 x 78 mm gate and older (Graphic and Graflex) with no pin rollers and a 56 x 82 mm gate.</p>

[thirteenthumbs]

<p>Dan,<br>

Apparently Graflex started using pin rollers before the Rapid-Vance Lever wind. I have a Knob wind with pin rollers and the narrower film window.</p>

<p>I prefer a Rapid-vance over the knob for ease of operation. Both have their weaknesses. A lazy lever that does not return may benefit from a CLA.<br>

Michael, read http://www.graflex.org/helpboard/viewtopic.php?t=6391</p>

[dan_fromm2]

<p>Chareles, you're right. I have a couple of late Graphic/Graflex shells with pin rollers.</p>

<p>In addition, SKGrimes offers a pin rollering service.</p>

[michael_przewrocki2]

<p>i have a rapid vance insert for 6x7/220-its showing 20 images on the counter. That is from RH20. i have read somewhere that these inserts could match in other RH-backs but there may be restrictions. e.g. it would be nice to use this 6x7/220 in RH8-6x9. Possible?</p>