The Digital Darkroom

I have only taken a look at this page on 14/07/2024 after a break of I don’t know how many years, so just about everything on this page is completely out of date. O.K. so I’ll re-write the page and bring you up to date with the current state of 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 Trius-M26Cs or ASI 2600MC Pro CMOS cameras are pre-processed before taking them into PhotoShop 2024 for the final processing steps to take place.

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Lets take a quick trip around the room.

Computing Power

The computer behind it all is based on an AMD Ryzen 5 3600 6-core processor running at 3.60 GHz, this works with 64Gb of RAM which you can see (4 sticks) glowing with all the colours of the rainbow behind the glass screen on the computer case. There are several Tb of internal hard drives and there’s external network storage of 4 Terabyte for all the image data using a Network storage unit with 4 caddies, each with a 1Tbyte HDD.

I use four 24″ LCD monitors (Iiyama – ProLite E2407HDS) so that I can keep the uncluttered image to be worked on sitting on the bottom right hand monitor, while all the menus I am using are on the monitor above it. The top left hand monitor is then free for Internet work, and the bottom left hand monitor is free for anything else going on.  

Printing

I use the superb HP Designjet T230 four colour (CMYK) printer to print out 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.

Pre-processing

The pre-processing is as follows.

  1. Calibrate (using artificial flats only) the raw FITS data for each sub-exposure using Maxim DL.
  2. Colour convert the calibrated raw FITS data for each sub-exposure using Maxim DL (de-Bayer).
  3. Open up each sub-exposure and check the image for anything that won’t be taken care of with the SD mask combine function in Maxim.
  4. Remove unsatisfactory sub-exposures.
  5. Use the SD mask combine function in Maxim DL to stack all the individual sub-exposures together.
  6. Save the resulting colour-converted and stacked file as a floating point IEEE FITS file.
  7. Convert the floating point IEEE FITS file to a 16-bit TIFF file to import into PhotoShop
  8. Import the 16-bit TIFF file into PhotoShop 2024 for the final touches. I now tend to do all the image processing myself nowadays as Noel Carboni has graciously passed on to me just about all that is necessary to produce a half-reasonable image – AND – Noel now has his dream job, working for Adobe PhotoShop which takes up all of his valuable time.