Sinar Norma Compendium
I make most of my photographs using a Sinar Norma view camera, and I like to reduce in-camera and printing flare as much as possible. I believe that low flare contributes to pleasing tonality in the final print. To reduce in-camera flare as much as possible, I use a compendium shade on every exposure. One of the nifty things about the Sinar system is the forwards and backwards compatibility between camera models. Sinar used the same dimensions for their monorail on the Norma, the F, and the P line of cameras, so many parts can be interchanged between those camera systems. For my Sinar Norma, I created a compendium shade using a combination of a Sinar F multipurpose standard, a standard bellows, a bellows clip, and a Sinar hexagonal rod. The F-line multipurpose standard sits on the front end of my camera's monorail, and the compendium bellows, supported by the hex rod and bellows clip, extends backwards towards the camera's lensboard. [caption id="" align="alignnone" width="600" caption="Sinar Norma with compendium made from F-series multipurpose standard, hex rod, and bellows clip"]
[/caption] Because I use many lenses that are can easily cover 4x5" or 5x7" film formats with my 6x9cm film back, I have a surplus of non-image light that enters my camera. This non-image light can reflect off the inside of the bellows and contribute to in-camera flare, so I reduce it as much as possible using a compendium mask. [caption id="" align="alignnone" width="600" caption="Sinar Compendium Mask"]
[/caption] I have been very pleased with this compendium arrangement in terms of functionality, but it is quite heavy. I haven't put it on a scale, but it probably adds two to three pounds to the camera's weight. My friend John Wimberley shared the details of an elegant and lightweight compendium that he uses on his Sinar Norma, and I decided to duplicate it for my camera. This new shade is a Linhof Technikardan compendium that is adapted for use on the Sinar Norma. The Linhof shade is mounted to my lensboard using a flash pivot bracket. This one: http://www.bhphotovideo.com/c/product/109450-REG/Kaiser_201200_Adjustable_Flash_Shoe.html. Note that I use a lensboard reducing adapter so that I can use the smaller Linhof Technika style lensboards in my Sinar. The lensboard reducing adapter stays put on the front of my camera and provides a flat surface to mount the flash pivot bracket to. The flash pivot allows the compendium to be swung out of the way when changing lenses or mounting or removing filters. At the rear of the compendium, you will notice a contraption placed in the 4x4" rear filter slot. It is a light baffle that keeps as much light as possible from entering the rear of the compendium. The circular ring of the light baffle is made from a 3/4" length of 3" ABS pipe that closely mates to the outside of the filter ring (67mm on all lenses) of my lenses. The inside of the light baffle ring is covered with black flocking paper. [caption id="attachment_331" align="alignnone" width="600" caption="Compendium mounted on camera, swung to side to access lens"]
[/caption] To create the compendium mounting bracket, I simply positioned the flash pivot bracket such that the shade is centered over the lens, drilled a hole in the lensboard adapter board, and used a 1/4 20 bolt to attach the bracket to the lensboard adapter board. [caption id="attachment_329" align="alignnone" width="600" caption="Hole drilled in lensboard for flash pivot bracket"]
[/caption] Well, that's not all there is to it. :-)
Design Notes
For the flash pivot to sit where I wanted it to go AND provide clearance for Copal 1 shutters (the largest I currently use), I had to put a 1/8" thick aluminum spacer underneath the flash pivot. The compendium shade puts two forces on the flash pivot mount:
- A downward torsion, resulting from the weight of the shade
- A circular torsion (around the axis of the screw that mounts the flash pivot to the lensboard), resulting from the off-center placement of the compendium rail.
To help with the circular torsion, I used a small length of 1/8 x 3/4" aluminum bar next to the flash pivot mount as a brake to keep the mount from rotating. The 1/4 20 machine screw that holds the flash pivot mount to the lensboard adapter does all of the work of resisting the downward torsion and most of the work of resisting the circular torsion, but the aluminum brake helps with circular torsion as well. The mounting hardware is shown in the picture below: [caption id="attachment_327" align="alignnone" width="600" caption="The mounting hardware, showing the stop screw (left), brake (middle raised piece of aluminum with two small screws through it), and flash pivot bracket (right)"]
[/caption] The nut-screw combination in the left of the picture is a settable stop to align the compendium parallel with the lensboard when the compendium is swung into place. The picture below shows what the back side of the mounting hardware looks like. The brass strips under the head of the leftmost screw are there to provide a surface for the screw to sit on. Without them, the screw head would be sitting on a "ledge" only about 1/16" wide, which is not very strong, and would encourage the screw to torque off center. [caption id="attachment_325" align="alignnone" width="600" caption="Back side of the lensboard, showing the mounting hardware"]
[/caption] Because film reflects a significant amount of the light that falls on it, I believe it is important to cover the back side of the lensboard with flocking paper, to reduce in-camera flare caused by light scattered off the film during exposures. To this end, I've covered the back of my lensboard adapter with black flocking paper: [caption id="attachment_326" align="alignnone" width="600" caption="Back side of lensboard adapter covered in flocking paper"]
[/caption] Here's what it all looks like together on the camera: [caption id="attachment_330" align="alignnone" width="600" caption="Compendium mounted on camera, positioned to make an exposure"]
[/caption] [caption id="attachment_328" align="alignnone" width="600" caption="Front view of compendium"]
[/caption] And finally, the front filter slot of the compendium accepts 4x4" masks. I have several of these, sized for different focal length lenses. These masks allow me to adjust the compendium such that virtually all non-image forming light is blocked before it even enters the lens. The masks are made from .060" copper-clad circuit board, covered on the rear with flocking paper. [caption id="attachment_338" align="alignnone" width="600" caption="Compendium with small mask mounted"]
[/caption] The result of all of this is an efficient, lightweight compendium that has movements and does exactly what I want it to. What more could I ask for!
Why Bother?
Whenever I discuss my flare reduction techniques with other photographers, they invariably ask "Does it make a difference?" or "Why go to that trouble?" I haven't done any rigorous testing to back up my opinion, but my opinion is that reducing flare improves the tonality of the resulting print, and that is why I trouble myself with things like a really good compendium shade. After paying attention to reducing in-camera and enlarging flare, I'm making the best prints of my life (at least technically).