The Digital Darkroom
The photographic “darkroom” takes on a different guise when you work with digital data. This picture shows my “digital darkroom” where FITS images from the SXVF-M25C and other cameras are pre-processed before sending them off via Broadband link to Noel Carboni for further processing and enhancement.
Lets take a quick trip around the room.
The computer behind it all is based on an Intel Quad Core (four processors) running at 2.55GHz and with 8.0G of RAM (Windows 7 64-bit). There are two 500Gb internal hard drives and there’s external network storage of 4 Terabyte for all the image data using two “Icy Box” caddies, each with 2 x 1Tbyte HHDs.
I use three 24″ LCD monitors (Iiyama – ProLite E2407HDS) so that I can keep the uncluttered image to be worked on sitting on the central monitor, while all the menus I am using are on the right hand monitor. The left hand monitor is then free for Internet work. The keyboard and mouse are wireless.
I use the superb HP Designjet 130 six colour printer to print out our images to a maximum size of A1. I use 200 g.s.m. satin finish photo quality paper and I can testify to the resistance of these prints to fading as I have had an image of the North America and Pelican nebulae [on the wall behind the left hand monitor] in direct sunlight for over 4 years with no apparent adverse effects – very impressive! By comparison, a simple print from an A4 colour printer faded in less than 2 weeks under similar conditions.
You can also see a number of other A4-sized images on the wall being “life-tested” under fairly harsh lighting conditions.
The pre-processing is as follows.
- Colour convert the raw FITS data for each sub-exposure using Maxim DL (de-Bayer).
- Open up each sub-exposure and check the image for planes, satellites or PEC glitches.
- Remove unsatisfactory sub-exposures.
- Use the SD mask combine function in Maxim DL to stack all the individual sub-exposures together.
- Save the resulting colour-converted and stacked file as a floating point IEEE FITS file.
- Send the IEEE floating point FITS file to Noel Carboni for further processing into a deep-space work of art.