Cambo Digital Repro #3 – WRS400 REPRO Camera
There are several cameras available from Cambo that can be used for digital capture. The camera shown is the WRC-400 REPRO an extremely lightweight and compact platform.
The WRC-400 is a technical camera that is precision machined from high grade aircraft aluminium, to match the demands of accurate capture. You can use the camera on a copy stand or Studiostand to reproduce cultural heritage, artwork and artefacts.
Why use a technical camera?
There are several reasons why a technical camera should be used, of course this is dependent on the quality of image you require and the output reproduction.
High quality resolving lenses from Rodenstock and Schneider should be used, these are classed as digital lenses. A wide range of digital backs can be attached from Phase One, Leaf, Hasselblad and Sinar, several different camera mounts are available.
A technical camera is more flexible when used for reproduction work and has the added advantage of applying camera movement (shift) that isn’t available when using a medium format camera system.
Capture using a technical camera
First you will need to assemble the camera and positioned it using the built-in levels so that the capture will be squared. There are horizontal and vertical levels built-in to the WRC-400.
What is Camera Movement?
If you look carefully at the WRC-400 image you will see a chrome wheel to the left and a scale with increments 20mm to the left and 20mm to the right. At the zero position the sensor will be positioned exactly in the middle of the capture area. This camera movement is called shift, as we can shift the sensor to the right and to the left and then stitch the images together.
If you choose to use a large medium format sensor then there will be less shift as you can only move the sensor within the image circle. This is restricted when using a medium format camera as there is no rear shift and you can not stitch two images together as you can with a technical camera.
For the purpose of this blog let’s say we have a sensor that is 44x33mm as a larger sensor is out of our price range. We can still capture more pixel information by shifting the sensor to the right, to the left and then stitch the images together.
The image below shows a 44x33mm sensor capture area, the rings around the sensor is the image circle of the lens. The Blue image circle is from a Rodenstock 60mm lens, whereas the Purple image circle is from a Schneider 90mm lens. The image circle varies depending on the lens structure and focal length.
As already indicated the WRC-400 has 20mm shift left and 20mm right, totalling 40mm. As you can see below we have shifted the mid-point of the sensor 16.5mm to the left and 16.5mm to the right, doubling the total capture area.
- The sensor capture area is 44x33mm, by shifting it is now approx 44x66mm.
- Pixel resolution is doubled from 50Million pixels to 100million pixels.
- The print output at 300dpi is increased from 70.1×52.6cm to 70.1×105.2cm
Note: The capture and output sizes will vary slightly as there will need to be a small amount of overlap for stitching. Also the aperture used will make some variation. However, the image will be almost double in size with 2 captures.