Saturday, April 23, 2011

Using a Cambo WRS Medium Format Technical Camera

I've written briefly about the RF75 a couple months ago and wanted to add a few comments after more usage. Lee designed the RF75 for use on rangefinder cameras which by their nature are small compact bodies using equally small compact lenses. Shortly after reading about this system I decided to try it on my Cambo WRS1000 technical camera thinking that while the lenses are larger than my Leica M9 the filter threads are very close to one another.

The RF75 filter system consists of 2-basic parts; the adapter ring which attaches directly to the lens using the filter threads and the filter holder which attaches to the adaptor ring and is held in place with a spring loaded plunger. The adaptor rings range in sizes from 39-67mm. The filter holder can be adapted to hold one or two 75x90mm filters along with an optional clip-on polarizing filter. I found I needed adaptor rings of 39, 46, 49 and 55mm to fit my Leica lenses however I a smaller ring for my Medium Format Schneider 72 and 120mm lenses and now use 2-step rings (40.5-52 and 52-55) which are then connected to the 55mm ring.

My Cambo lens kit consist of three, 35mm Schneider which has a center filter attached, as well as Schneider 72 and 120mm. I've used the Lee RF75 with great success on the 72 and 120mm lenses using the step-rings and found I get no vignetting.

Valley of the Gods
120mm, processed using Capture One Pro & CS5

Along Comb Ridge
35mm, processed entirely in Capture One Pro

Along Comb Ridge
35mm, processed using Capture One Pro and CS5

Post Processing:

I use a Phase One P45+ digital back to capture the images with the WRS. A technical camera allows the photographer to use movements thus making better use of the lens circle. While the lens itself remain stationary the back moves around the lens, left to right and up and down; these movements allow for multiple image captures with very little image distortion. The down-side is that the movement of the back on the rear of the lens can introduce color shifts however these can be easily fixed.

Valley of the Gods
120mm, 3-image panorama processed in Capture One Pro & CS5

This is the same image and shows the joy of digital capture. I enjoy the simple look of some landscape images in black and white and can experiment with the image. This is the same color image above it however I took the file and using Nik Silver Efex Pro turned it into a black and white rendering using Agfa APX Pro 100 film look. I feel both images look good and each it's own special appeal.

While it's slightly more involved, my normal workflow in processing a medium format image is first opening Phase One's Capture One Pro 6, a program made specifically for Phase One digital backs.  Capture One "fixes" the color shift and also allows for a multitude of other processing.  Another processing tool I normally use is Adobe Photoshop CS5 where I can stitch multiple images together into one large panoramic image.

Valley of the Gods
120mm, 3-image panorama processed in Capture One & CS5

Sometimes no matter how hard you try you're still left with a bad image.

This is the result of 5-images shot in portrait mode, using the 120mm lens with the RF75 filter system attached (I used .9 and .6 neutral density filters to get a more dramatic sky).  I was so intent on the placement of the filters that I completely forgot to double check the focus of the lens thus the image is ever so slightly out of focus.

The next entry addresses Bluff UT, Comb Ridge and Valley of the Gods in more detail along with images from Sandy's Canon 1DsIII and my Leica M9. We'll also be including at least one video taken from our new Ford Raptor showing the beauty of the area we drove through.

Stay tuned...


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