Saturday, 3 August 2013

60 megapixels of near-infrared

Back in April, I wrote about the Leaf Credo wide spectrum backs which had been set up to shoot near infrared out of the box at resolutions up to 80 megapixels. Yair Shahar (from Leaf) and I spent a couple of hours on Primrose Hill in London trying the 60 megapixel version out with both a Mamiya body and a technical camera.

The image as shot with the 60 mp back is an extraordinary 8984 by 6732 pixels. With a suitable lens the resolution is also impressive, giving scope for huge detailed prints. To give you an idea, here is a 6200 by 4000 crop from a shot through a 950 nm filter looking south from Primrose hill directly towards the Shard.

If I zoom in on this until you're looking at it pixel for pixel, this is what you see just to the left of centre on the horizon, between the two dark buildings to the left of the Shard.

This was with a Mamiya 80m lens (half a second at f9, ISO 50). With a technical camera lens the image was even sharper. I have found that infrared can produce very interesting cloud images even on an overcast day, presumably because of a different balance between the brightness of the ground/trees (which show up bright in infrared due to the Wood Effect) and the cloud base. You can focus using live view with this back, which is pretty well essential for such a shot, as is a tripod. The back has no anti-aliasing filter. In general you don't need one for landscapes although there was one distant building in the scene we shot that exhibited some moiré, which was easily removed/disguised.

Leaf use another of our shots from that test on their guidelines brochure.

I had hoped to be able to do more infrared tests with the Credo during July but, unfortunately, it wasn't possible due to my work load. But the main point is made by the brief trip to the top of Primrose Hill, which is that you can produce dramatic landscapes with this kit. I'd love to see what a real landscape photographer could come up with, given more time and better weather. The Credo WS back is also proving of interest in art conservation and for forensics. There is a lot to be said for the 'shoot first and examine later' ability of very high resolution images.

[My thanks to Leaf and Yair Shahar for their help with this test.]

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