Finished off insulating, dessicant packs, bagging and sealing the camera today. Photos attached, that's the Ha filter in the filter drawer. Final step (simulated here for illustration purposes) is argon gassing then it goes into its sealed plastic storage box until I mount it on the scope. Waiting, waiting, .....
Eta Carinea will probably be the easiest, it s nice and bright and I plan on using my 10" f5 newt just for the speed advantage. I will start with Ha and try to get a handle on sub lengths before I worry about anything else. I have been reading about narrow band image processing, It's clear that I have a lot to learn - again. Don't expect any wonderful Hubble Pallet images in the near term.
Finally last night I was able to conduct some Ha imaging testing. The test object was Eta Carinea. The Moon was just a couple of days past full and about 95+ degrees away (on the Azimuth) from Eta Carinea at the start of the run. The scope used was the Skywatcher MN190, which at f5.3 is relatively fast, and it is well baffled (something I thought would be important on a night full of moonlight). The camera sensor was cooled to 0C during the test. I shot 8* 300" lights, and dithered between subs to enable processing out of the bad column in my sensor. I used BYEOS and Metaguide and was surprised the dithering worked so well, just select Metaguide on the setting page and press the button. I think I left all the other dither settings at default. Shot Darks, and Bias Frames after the Lights, and then did the Flats this morning at dawn. Stacked in DSS, and the Hot and Cold pixels were removed along with any evidence of the bad column. I checked the Flats and the bad column can clearly be seen, and I have a bright pixel in the Darks but all of this was removed by DSS (and dithering of course).
I have attached a jpg below, and remember it is small for posting here and honestly the quality is not great in this little file. The larger version is up on Astrobin here, and I recommend you look at that instead of the little one:
In processing with Photoshop, the only thing done was some Auto Levels, I am sure there is room for more work there.
Pretty happy with the image detail, the Fits version really leaps out of the screen. For a limited test run of just eight subs I think it (the camera) is working pretty well and I am pleasantly surprised with the Ha gathered on a very bright night.
Comments and feedback/suggestions welcome.
Just an update on the Mono Camera testing. Completed Ha, OIII, and some SII on Eta Carinae, but I still need to shoot some more SII (its very faint on that target); and to process the colour properly (another skill to learn).
I have managed to shoot some Ha of the Lagoon Nebula, and early morning target at this time of year (like 2am onward). Here are the links to the first hour's worth of Ha from the Lagoon.
I am happy it clearly shows the Bok structures in the Ha clouds.
I had a problem with Dark file management, due to DSS file naming conventions, I mistakenly picked up Darks from my colour camera for stacking and this led to the hot pixel cosmetic processing in DSS not working correctly. The mono camera has some debayering artifacts that I process out in DSS but it relies on having the correct Darks for that sensor and the associated Flats. So I have had to create two separate file libraries to avoid this in the future.
Just waiting on the new small aluminium cooling block to arrive so I can complete the liquid cooling system for the mono camera. For now it continues to run on the heatsink/fan cooling system, which works fine but I want to get some weight off the camera which will help with scope balance. That's all for now.
I have completed some testing shooting on the Lagoon Nebula, and processed it using the following pallet: Ha (red),OIII (green), and SII (blue). The light subs (10*360" = one hour of signal for each filter) were, I believe, actually over-exposed to a certain degree, not something usually an issue with narrow band from what I understand. I guess shooting at f5.3 for six minutes each at ISO1600 was just too much exposure for such a bright object. I will reshoot in the future with shorter subs (at least for Ha and OIII), and/or lower ISO, to try and stop the burn out in the centre.
So here is the Lagoon image as it sits on Astrobin:
I believe the resolution is suffering due to the curve and exposure manipulation I had to do to reduce the brightness in the centre. Individual unprocessed subs in Ha look much better in terms of resolution. More to learn for sure.
Note I have deleted the previous Eta C test file (from the post below this one) as it frankly was embarrasing.
That's really interesting Glen I'm going to have to try this myself as my scope is f/5.5.
At risk of sound like a stuck record, you're getting some really interesting data that - I feel - PS isn't doing justice. You could use getting to grips with PixInsight as that has a number of tools to handle high dynamic range objects such as this...
Could also be resolved by using masks in Photoshop. Had a lesson in it last year and it worked well but Id be struggling to remember the correct procedure now.
Essentially you copy your first layer and enhance layer 2 a bit (curves) then partially erase the brighter section to reveal the original, rinse and repeat. Merge the layers at Save or otherwise you save a huge file with multiple layers.
Must have another play with it ... it was very effective on Trifid and Lagoon, our test image.
I have today started work on the Mark 2 version of this mono Canon 450D. I have a spare 450D that i use for sensor testing. I have pulled out the sensor and removed the stock filters and the cover glass in preparation for debayering it in coming days. As insurance i have ordered another spare sensor. I want to try a new approach to debayering, which i tried out today on one of my dead sensor collection. The goal is to produce a cleaner, undamaged sensor that does not have hot pixel areas and any bad columns. Sure those faults can be processed out but they bug me and i think i can make a clean one based on my experience so far. This will be a background task, when the sky is clear i will continue with my narrow band testing on the mono mark 1.
BTW i have modified a heat gun into a coverglass removal tool which i will feature soon.
Brent i am familiar with masking, it comes in handy on the Orion Nebula as well. For now i want to try and get the exposure sorted out for that scope and camera combination,
.Dunk i cannot bring myself to join the PI cult, i will persist with PS which i am just starting to understand. Thanks gents.
Guess i am too old to change at this point. I tried a PI trial version a couple of years ago and could not make any sense of it. It is like learning a new language with no common roots with your own. I gave up and deleted it. I suppose if your an object oriented programmer it makes sense, but to my old Cobol brain it was too hard when PS was just sitting there.
Glen, you're never too old! I'm not a programmer, but didn't find PS intuitive when I first tried it. It takes a bit of getting used to like most software with any depth. Many of the functions have names you may or may not be familiar with is the first challenge, then it's how to put one after the other as a workflow. You're used to that from using multiple tools as it stands. It's just a different approach.
There's a bunch of resources out there to help you get started...you'd be surprised how quickly it's possible to get going with it. And the results are better
To the gods of DSLR modding:
I have given in, the temptation was too great. 2nd hand half-broken 450D is on its way IR mod and cold finger cooling. I will leave my IR-modded 1200D as a spare... at least for now.
Thank you all for great posts/discussions about the progress. I have spent half a day today taking notes from the 3 main cold finger threads and preparing for the camera arrival (and preparing a shopping list).
Glen, I can see that you used the flat copper finger design for your mono DSLR. Apart from not having to bend the copper and the lack of connectors, any other advantages/disadvantages compared to the original? Did you need to modify the original Rowland's dimensions for the flat version (possibly shorter)?
And best of luck with debayering the mark 2 sensor...
Luka both of my cooled cameras use the 90 degree bent cold finger as per Rolands design. They bend toward the back left side and are supported by carbon fibre brackets that i made to take any load off the finger ( the brackets screw to the camera using the tripod hole). In my second camera i opted to take it straight out from the sensor as i was eliminating the little comms board. But the finger still bend 90 degrees to the back outside of the camera to mount the TEC, only the little step bends were eliminated. The advantage is you don't have to do the fiddly little step bends to create clearance to put that small comms board back in. However, i did make a carbon fibre spacer that goes in the spot vacated by the comms board, so it supports the cold finger as it comes out from the back of the sensor board.
I also sprayed the cold finger with four coats of PlastiDip rubber paint to help insulate it and cut down on frost build up.
BTW i picked up another working 450D on ebay today for $86. It had a scratched rear screen and no one bid on it. There are some real bargains around if you keep watching for them. It is worth more than that as parts.
Good luck with your mods and ask anything you need to clarify or help you along the way.
Hi Glen, thank you for a quick reply. I was talking about the step inside... may go with the simpler straight design (+ 90deg bend outside).
Do you have any drawings of your fiberglass holder? I may try 3D printing one (no camera here yet).
And I have to agree with the ebay as source of cheap 450Ds... I picked up one yesterday for $93 (posted) with a broken flash. And it even comes with a 18-55 lense. You may have even been bidding for it :-)
Blimey, wish I could find a few of those over here at that price !!
Pulling the comms board out certainly simplifies the cold finger install. Also means more copper going in for thermal transmission.
Mine sticks directly out, made a Alum angle bracket off the tripod hole to support it
Brent, they are not that price all the time. I have been watching and waiting for one that is broken but not too broken.
I was wondering, with all the issues of possible leaks in the sealing bag, has anyone put a humidity sensor inside? I am currently working on a microcontroller controlled dew strap heater and was planing to use this to control the peltier as well (got 10 PWM channels). This can easily be extended to measure the humidity/dew point inside the bag and stop the cooling and sound an alarm if it goes too high.
nah just the best tool for the job 
