Robin Krish , Mar 21, 2010; 07:25 p.m.
Hello All,
I'm pretty new to Medium Format and have just acquired an RB67 Pro SD with a K/L 65mm lens and a NPC Poloraid Back MF-3. I recently used a pack of Fuji FP-100B instant film. After shooting one frame I noticed that one side of the picture has a vertical black stripe running across...this happened in the 2nd and 3rd frame too!!
My question to you all ...is this because of the difference between the RB's 6X7 format size the the FP-100B's different size? I have to physically trim the photograph to get rid of the vertical strip but lose the white edges around the image. It looks like the vertical black stripe is the unexposed part of the film. Is this something normal? Is there any other instant film availalbe to fit the 6x7 format?
Any input is much appreciated. Thanks in advance!!
Tom Emerson 
, Mar 21, 2010; 07:48 p.m.
Yes, the size of the image on the Polaroid will be 6x7cm: you will not get "full frame" coverage of the Type 100 area on the 6x7.
David McNiven , Mar 21, 2010; 09:09 p.m.
I don't remember the NPC arrangement - sorry - my SD has the Mamiya Polaroid back and the picture area is 7 x 7 cm. so it fits to the camera without the rotating adapter being between the two.
Do your pictures match the size of frame as measured at the darkslide? Does the rotating back stay on the camera when this Polaroid back is fitted? What size is the picture you're getting?
If the image area is offset could it be fitted wrong way round on the camera - or is it symmetrical?
John A 
, Mar 21, 2010; 10:21 p.m.
the NPC back, without the masks, will give you appox. a 7x7cm image, but the polaroid(Fuji) itself is approx 3-1/4x4? or so. So no matter what camera you use, unless it is one of the polaroid cameras made for this pack film, you always get a black area with an MF camera.
Jim Krupnik 
, Mar 23, 2010; 08:06 p.m.
This is a scanned Polaroid print of a target without a mask in place taken with an RZ. It's the same for an RB, or an RZ. This was with a Mamiya back, but the NPC back has the same arrangement. I often skip the mask if the print is the final product. This was from a local lighting workshop I put on for a group last weekend. This was the basic "direct, camera mounted speedlight" shot showing the "beautiful, soft nature" of camera mounted flash, and things began to look a whole lot better from there.... :).
Robin Krish , Mar 26, 2010; 11:23 p.m.
Hi,
Thank you all for your responses.
Jim Krupnik: What kind of mask are you taking about? Is it somethign to crop the finished pic when you scan it?
Jim Krupnik , Mar 27, 2010; 06:07 p.m.
Robin,
The Polaroid mask is a special type of darkslide for your Polaroid back. As shown in the photo I posted above, the Polaroid back captures an image that measures about 7x7 cm square. That is fine when your goal is just Polaroid prints, as it is the largest direct image the RB/RZ cameras can capture. That was the case when I was using Polaroid prints to demonstrate the basics of flash lighting in the workshop a few weekends ago.
On the other hand, people most often use Polaroid film to make sure that they have their lighting arrangement, exposure, and scene composition perfect before they take the final production shots on regular film. In that case, it is important that the image captured on the Polaroid print is identical in size to the 6x7 cm image that the 120, or 220 film back will capture. The way to make that happen is to slip the 6x7 mask slide into the empty darkslide slot in the Polaroid back before you shoot the scene.
That will result in a black framed image on the Polaroid print that is identical to the image you will capture on film. Now you can study the scene on the Polaroid print for composition, and not have to guess about what will actually end up in the money shot on film. The picture below shows a standard Polaroid darkslide on the right, and a 6x7 cm mask slide on the left. Notice that all normal Polaroid darkslides are finished in bright metal, and all Polaroid mask slides are finished in black. That gives you a solid visual key as to which slide is in the back at any paticular moment, so you don't risk wasting film in a false exposure with the darkslide in place, or by removing a Polaroid back from the camera with the mask slide in place.
Always remember: Polaroid backs do not have any film saftey interlocks at all. Look before you leap..
The mask slides are often lost long before a Polaroid back makes it to the used camera shop, but they are cheap when you can find them. Call KEH, and ask. I'd bet they have a hundred of them. In any event, get at least one. It is a very simple tool that prevents a load of headaches....
Have fun with your Polaroid back!
Robin Krish , Mar 27, 2010; 06:58 p.m.
Hi Jim,
Thank you for the great explaination and picture!! I get it now!! I was trying to figure out how to get an even crop of the image...your post tells it all!!
Regards,
R
Jim Krupnik , Apr 03, 2010; 12:53 a.m.
Robin, you are very welcome. That is what sharing questions, ideas, and experience on the internet is all about. Helping you "get it" made my day!
Mac Hayes , Feb 11, 2012; 09:25 p.m.
There is a difference with the NPC back, in that the square image is all on the left side of the finished print. There is a 7/8" (22mm) black region on the right side of the finished prints, that was masked by the RB67 body. The reason: NPC puts the film pack offcenter to the left side of the camera body, while Mamiya centers the film pack, giving about 3/8" black vertical borders on each side of the print. With the Mamiya back you get about 4-5mm more image width, that NPC blocks in order to give that extra side with white border on the left side of the print. Aside from possibly becoming an art-form of producing these prints for gallery display, the Mamiya solution does give you that little bit more image at the sides for judging your exposure, etc.
This puts all the unavailable print area on the right side of the finished print, a black vertical area
