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fwm891

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Everything posted by fwm891

  1. The unit looks more serviceable than mine, I hope it turns out well for you. As a guide with mine cooling the camera from ambient took about 2.5 hrs to get noticeable results in test dark frames. The housing cools quite quickly but it takes time for the camera body to release all the stored heat - hence the reason I pre-cool in a fridge! Francis
  2. jsigone / Olly, Many thanks. Dark skies at the moment are virtually impossible. Final 3 frames of this sets show considerable brightening as dawn began its approached (about 02:20 ish). I'm try a re-process this morning omitting those frames to see if I can extract anymore information. Like you say needs more subs and less LP... Francis
  3. First attempt at the Cocoon neb. Details: 60 mins (10 x 6 min subs) at ISO 800 with Canon DSLR, Altair Astro 8-inch f4 and Baader MPCC flattener and UHC-S filter. Camera was cooled to 1º C in my chiller box and guided with a Helios ST80, QHY5 and PHD on NEQ-6 Pro mount. Not sure what colour it should be so its a best guess - looked on the web for some idea but it seems almost any colour will do! Comments gratefully accepted (good or bad)
  4. Leo, Cooling the camera reduces the thermal noise inherent in CCD and CMOS camera detectors. Dedicated CCD cameras for astro work will go way below the levels attained with the chiller but it does do a great job with DSLR cameras.
  5. Carole - I don't have a problem with combining threads as they are virtually the same... I'm trying to image the Cocoon neb with mine at the moment - body temp down to 2º C.
  6. Tip: I used the heatsinks and peltier unit from a Halfords beer cooler (12 litre size) although from what I could see of the coolers they are all powered by the same units. I used a couple of fans from Maplins as replacements (now I have a useless drinks cooler to keep all my odd cables in!
  7. Re: Hole for cables - yes there is an aperture about 25 mm (H) x 8 mm (W) in the opposite end to the heatsinks, (the hole is plugged with a piece of foam rubber to form a seal) this allows access for the usb and power cable to the camera. My original box although I made it with an aperture large enough to take the 'T-mount' adapter also gave me problems locking the flattener in place, thats why I modified the front panel to allow me to put the camera in as a complete unit. The modification also gives me a better seal around the flattener. In use I put a ring of foam rubber between the chiller
  8. Carole / Swag72, Mine weighs 980 gms or 2 lbs 2.5 oz + the camera body. Good idea about leaving the camera in a sealed bag, it may restrict the cooling slightly but make sure you put a small bag of silica gel or similar in with the camera to absorb any moisture as it will be trapped there. Also my UHC-S filter effectively seals the front of the camera so if you don't use filters you amy have to consider moisture getting directly onto the chip! Not had any problems with flexure at the focuser when in use. - Francis
  9. Okay- left more questions there!... Laser_jock99, I've replied there and left test image - Francis
  10. I'll try and get before & after shots - bit awkward though as the camera takes quite sometime to cool down. What I may do is shoot with a second body but it won't be the same model so results won't be exact comparison. Or I could shoot on different nights then conditions change etc, etc... Regarding noise levels its great I've done a number of tests at different iso rating with the camera body capped in the chiller and taken exposures during cool-down from ambient. Initially noise shows as bright RGB + hot pixels on a black background. Although the noise pattern remains during the cool-dow
  11. Hi - Been trying out the DSLR chiller again and captured 5 x 10 min subs of NGC 6992. Details: Altair Astro 8-inch f4 Newtonian with Baader MPCC corrector, Baader UHC-S filter, Canon 450D (self mod-full spectrum) shot at ISO 800 on NEQ-6 Pro mount guided using Helios st80 + QYH5 + PHD. EQMOD. Sub frames combined, with darks, flats, bias and flat/darks in DSS and tweaked in PS CS3. These images were a trial of the chiller which had taken the camera body to 16º C below ambient (about 1º-2º C) on the night following a pre-cool in the fridge for about 3 hours to make sure the camera was cooled rig
  12. Hi Martin - Thanks. The Baader MPCC and Altair 8-inch f4 seem very well matched. I took great care after getting them to ensure all the mechanical components were aligned. Collimation seems stable and needs little tweaking. The only thing I find with the OTA is the focuser shifts/tilts if its locked but the tension adjuster is good enough to even hold my DSLR and chiller box! Francis
  13. Laser_jock99 - I've posted some photos in the DIY section - Francis
  14. I have attached a few images of a home made chiller box I use with my Canon 450D DSLR body. Essentially its the same as the Gary Honis V 3 unit with a couple of changes to suit me... Its constructed from aluminium sheet and uses a Peltier heat exchanger as the cooling device. There's a large heatsink and fan unit on the exterior to remove unwanted heat from the peltier, and a smaller heatsink and fan inside to circulate the chilled air. The box is sealed as well as possible to retain the cold air and insulated with polystyrene sheet. I pre-cool my camera and MPCC flattener in a fridge (in a se
  15. Thanks Mark. Laser_jock99 - I've built a chiller/cool box to take my Canon 450D along the lines of the Gary Honis version III unit. I've made a couple of alterations from Gary's to suit my working but its essentially the same. With the higher temperatures at the moment I've taken to pre-cooling the camera and MPCC corrector (in a sealed bag!) as a unit in a fridge for a couple of hours before I need them (this is because the unit will keep the temperature to about 15º C below ambient but taking the camera body from ambient takes a while so pre-cooling speeds up the process). Once enclosed acce
  16. Tried a session on the 'Wall' in ngc7000 with my Altair Astro 8-inch f4 and cooled DSLR last night. Also tried ngc 281 but creeping dawn cut the session short so will leave this until it gets a little higher later in the year. Also tried IC1805 but only managed a single frame which looked washed out so like ngc281 it will have to wait… NGC 7000: 10 x 5 min subs @ ISO 1600 NGC 281: 3 x 5 min subs @ ISO 1600 Both images processed in DSS and PS CS-3 Francis
  17. I use an old Helios 80mm and QHY5 as guider on my NEQ6 Pro with little problem. I also use an old Mintron fitted with an (older) 135 f2.8 camera lens as a finder - its shows me most of the fuzzies very well, infact better than the 80 / QHY5 combo! given that it integrates over at most 2.5 seconds of video frames...
  18. Cameras are normally modified so you can gain the red/near IR part of the spectrum which would distort normal daylight imaging. The spectrum passband of an H-alpha filter is narrow whether of 6, 7, 12, or 30 nm compared to the 'red' or IR transmit filters which Ha basically sits between. Your modified camera will pick-up all the light transmitted by the Ha filter. Some Ha filters also have spurious passbands well away from the intended Ha region (some UV/blue some deeper IR) so the way in which a camera has been modified may effect the filter choice. i.e. full spectrum or UV/IR cut mods...
  19. The Sun is approx 1/2º in diameter so you can draw to scale an arrangement that will produce the image size you need. (Light from the Sun will diverge at that 1/2º angle after passing through your pinhole) Image brightness and contrast are related to the size of the pinhole. Large pinhole brighter image - poor contrast less detail. Small pinhole, dim image - better contrast, better detail...
  20. Hi - For general everyday imaging I would have no hesitation in buying Nikon kit - For astro its got to be Canon. If you go the Nikon route and need to get your images to a laptop the Nikon capture software is V expensive - Canon supply their capture software free as part of the package. I've just retired from Pro technical photography after 35 years and during that time have used both Nikon and Canon kits but Nikon to me have the edge. Now I'm getting into astro imaging with DSLR's I like Canon and have a (self) modified 450D and a standard 500D. Noise in long exposures can be handled by the
  21. Nice set of instruments - Just a thought though, if you drop your cross bar and fix it to the saddle plate holding the main scope (then your guider second scope will be either side of the main scope) you will lower the CoG of the set-up and the amount of counterweights required. Made a great difference for me with my 8-inch f4 newt with a WO Zs80 and 600 mm mirror lens as guide scope on either side - allowed the extension bar for balance weights to be removed on my NEQ 6 Pro... Just a thought.
  22. Hi John et al, I'm looking for a 2" approx 2x barlow to use for photography at my telescope (8-inch f4 jobbie with a canon DSLR). Currently I'm using a 2x camera lens converter which works but... Looks like your all visual observers, I'm afraid I prefer imaging but would welcome any views/experiences from others...
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