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fwm891

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Everything posted by fwm891

  1. Very nice Carole - once you get your cooler active it will be nice to see a repeat. Francis
  2. Brill!! accidents happen - they normally cost me money - well done
  3. Agree with Earl - the Astrobaby instructions are very good - 1st thing I did with my NEQ6 Pro was to strip it down wash it out and regrease. Works very well now. Francis
  4. Hi Dave, You seem from the photos to have two problems: A central zone and an edge zone. I suspect (without numerical data to check) that your MOT working has caused a central depression - the edge doesn't look serious so: My inclination would be to work two short sessions TOT 5 min 1/3rd D, then MOT 5 mins 1/4 D both these should have a 'W' pattern to the strokes to smooth out the edges of your zones and take you back towards a sphere. Working much more MOT only will just deepen the central zone into a hole. You're really not far away so short periods of working, resting and testing. francis
  5. Dennis - Thanks. Getting good colour (sodium's OK) around Reading is nigh on impossible. I hope you have better skies around Harwich (unless your near the docks I seem to remember things being quite rural!)...
  6. Lewis / Dennis - Thanks all comments valuable. Agree about narrow cut filters, until you know who with the purse string thinks I have enough brownie points I'm having to make do... H-alpha first on the list. My Baader UHC-S filter gives 3 well defined colour channels in PS so I can separate those, its the Ha needed for clean luminance content, or atleast thats my thinking at the moment - you may change my mind?
  7. fwm891

    M16 quickie

    Lovely image - don't sell it - use it!
  8. Echo Peter Shah. Must get an Ha filter - love B&W work.
  9. A real Bernard Matthews shot! Bootifull
  10. Shot these images back in April and have been playing with them in DSS and PS CS3 on and off since then trying to 'see' which treatment gave the best detail... Still not sure as to me the colour emphasises some detail and grey shading others - what do others think?
  11. Come on - you'll be saying that like me you coated your own glass plates next!!!
  12. 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
  13. 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
  14. 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)
  15. 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.
  16. 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.
  17. 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!
  18. 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 box and the focuser to stop condensation forming on the flattener where it enters the focuser as the 'cold' is conducted well into the focuser which gets surprisingly cold after a long session (4 hours my longest run so far). Carole - hope your mods go okay. Francis
  19. 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
  20. Okay- left more questions there!... Laser_jock99, I've replied there and left test image - Francis
  21. 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-down the intensity of the RGB pattern drops leaving only the hot pixels at full intensity. Dropping the ISO rating also helps as would be expected. I've attached a set from an ISO 800 test, each image is a 100% screen grab from the same area of each frame. The control is taken at ambient with the timings of each 10 min sub shown. Cool-down from ambient with the chiller alone is quite lengthy hence the reason I pre cool the camera in a fridge so the chiller just maintains or slightly reduces the fridge cooling.
  22. 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 right through. I had also been playing with the scope configuration and had run 2 iterations with EQ-Align 2 to reestablish correct polar alignment as on my previous session PHD was asking the mount for some hefty corrective steps which had cause some frame to multi image on the same frame where things were skipping! Hope you like...
  23. 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
  24. Laser_jock99 - I've posted some photos in the DIY section - Francis
  25. 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 sealed bag) for a couple of hours as it takes time to get the camera body cold right through and use the chiller to maintain the cooling. It attains about 15º C below ambient. I keep a piece of kitchen toweling inside to soak up the small amount of condensation produced. Fans turn on when power is attached and the Peltier is activated by a separate switch in the 12 VDC supply line. At the end of a session the unit is left closed with just the fans running for a hour or two to prevent condensation forming as the unit slowly warms up.
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