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Fraunhoffer

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About Fraunhoffer

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    Nebula

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    near London
  1. Fraunhoffer

    Another attempt at Luna

    Hello - I meant that there was a conveniently placed star nearby for me to focus on, before swinging back. Things might have shifted whilst returning to the moon is another variable I guess.
  2. Fraunhoffer

    Another attempt at Luna

    Its one of these built into a camera adapter. It just screws in the end like a filter. Now Ive used it a few times - some mixed feelings. Its quite convenient to use. It makes the barrel of the adapter (or eyepiece) quite long so it doesn't always sit nicely into the hole. It doesn't have screw threads on the end of the Barlow bit, so not possible to use a filter. It might be better with a small subject near the centre, but with an extended object like the moon nearly filling the frame of a dslr- it wasn't so good. That night be just due the field curvature I suppose. I found that due to the spacing from the barlow to the camera chip on my set up the magnification was about x3. I might experiment with screwing into a spare barrel from an old EP and putting it inside the tube (since I only need the M screwthread for the camera) thus reducing the chip-barlow distance a bit. I did think about using a 'normal' barlow but the chain of things bolted together and hanging off the focuser gets big and sloppy. Added later. Thanks for your Q. Made me think a bit more about how to get the best out of what I have, After swapping a few bits around ( I knew there was a reason I kept that old eyepiece) Ive moved the Barlow lens inside (I could use any Barlow barrel) and now I can put filters on the end. Also after a bit more head-scratching I guess its a bit of a hard ask to fill a 25x15mm sensor when the Barlow 'window' is only 20mm diameter (mmh). I have another Barlow with a bigger window so some more experimenting I suppose. Now I also understand why only a 'webcam' sized sensor is needed to image a small object (eg Planet). Always learning ….
  3. Fraunhoffer

    Another attempt at Luna

    Every day is a school day... I went back to my various test shots to compare Prime Focus vs EP projection (above photo) and using a 2x Barlow camera adapter. I think the best photo for clarity and lack of CA is just the prime focus > in futur I will not bother with the Barlow (introduced CA) and the EP projection adapter (mushy photo). In all 3 I used a mask to find a good focus.
  4. Having just received a copy of 'Budget Astrophotography - Imaging with your DSLR and webcam' the full moon presented a wonderful opportunity to work through the example given for the moon. So here we are: 50 raw pictures on a Sony a5000 using a zoom eyepiece (to get a nice fill of the frame) for projection with a Bresser 102s/600 on Exos2 . ISO 200 1/100s. Bahtinov mask to get the focus. Conversion of .arw to .tif using PIPP. including clipping. Stacking with Registax using 43/51 frames. Creation of 2 layers (1 colour with saturation boosted and noise smoothed out + 1 sharpened b/w) and blending with PaintshopPro. Being self critical, The picture focus is slightly off on the LHS - which I think is due to so much stuff handing off the focus tube. My calculation went a bit wrong - I was hoping to use prime focus with a x2 Barlow - but it went just outside the frame - so I might try a mosaic another time. Any comments on how I could improve this (without spending a fortune or a week on the computer ) welcome. Thanks. PS - great book btw.
  5. Fraunhoffer

    How to do flats with Samyang 135mm F2

    Thank you - I was also wondering this very same thing.
  6. I found a old 35mm film cannister and following an idea elsewhere on this forum made a simple desiccating bung to go in the end of the tube to help keep the insides dry. (I decided to make it since the inside side of my diagonal started to mist up the other night when viewing near the zenith for a long time). Drilling holes split the plastic tube and so in the end I slowly carved the holes with a modelling knife and a needle file, (I suppose melting holes with an old soldering iron would also work) making sure the holes were smaller than the sachets I plan to use. Cleaned the finished item to remove any swarf and dust and popped it in the 37mm eyepiece holder. I also taped on the lid to reduce any risk that I pop the lid off and the whole lot slides inside the telescope due to my clumsy handling - waaahh. Regards
  7. Fraunhoffer

    Bresser Exos-2 / Meade 75 RA stepper motor 'step'

    looks very similar to a Vixen MT-1 in a black square case and DIN socket.
  8. Hello I just wondered - does anyone know the stepper motor 'step' angle for this mount when at sidereal rate. Ive searched ES , Bresser and Meade sites for the equivalent motor kits to go on an EQ5 type mount (144 worm turns / revolution) … but I cant find the RA stepper motor kit step rate or angle anywhere. Thanks
  9. Fraunhoffer

    More lunar lunacy!

    Very nice. How do you get such high resolution? Whatever I seem to do I end up with bits over exposed or in spite of focussing on a nearby star (using live view and zoom to get it right) I don't get high res like that. Does the stacking help ? Most of mine are just single shots.
  10. Fraunhoffer

    Dual Speed Focuser

    @hornedreaper33 Ah ok I think I get it. So pull the rubber knob off and undo the 3 screws.... screw top hat thingy in place and attach slow mo to the original shaft (minus rubber knob), and it is also attached to the top hat. What happens exactly when the 3 CSK screws are undone and the orange round plate removed. Is there a risk of anything dropping out (before I have a peek) ? Visions of springs and ball bearings dropping on the living room carpet....
  11. Fraunhoffer

    What did the postman bring?

    Book: Budget Astrophotography (imaging with your DSLR or Webcam) Something to read on a dull day - as well as browse the excellent tips on SGL
  12. Fraunhoffer

    Herschel on the terminator

    I spent ages with my little guidebook trying to work out what I was looking at here. At first glance it reminded me of a 'Mott and Bailey' castle over in the top right. So I took a photo to try and work out what is was in the cold light of day. Turns out it was Hershel near the N pole. First time :-).
  13. Fraunhoffer

    Dual Speed Focuser

    Can I check my understanding here - the flanges on the gear drive needs to be attached to the scope body in some way (e.g could adapt the orange ring / or make something similar) thanks
  14. Fraunhoffer

    I made my own heaters

    I wanted to follow this up with a Telrad heater. I have been successfully using a dew shield made of modelling foam a few times (from the template here: http://www.homebuiltastronomy.com/downbino/HomeBuiltAstronomy-TelradDewShield.html) but on occasions it would start to dew up around the edge of the Rigel window. After musing and sketching various designs using the resistors again I was not really happy with what I come up with. Whilst rummaging through my bits-and-pieces box I came across a discarded automotive ballast resistor. This is used when you upgrade your interior lights from filament to LED so the ECU doesn't think all the bulbs are blown. Its a 60 ohm resistor in an allow heat sink. Would make a handy 2W (and a bit) heater. It sits nicely on the front shelf of the Telrad secured with a small piece of double sided tape and doesn't obscure the view or fall off sideways. Happy to report it worked a dream at -2 last night, the front half of the Telrad was covered in frost and the windows on the rear of the unit - quite clear.
  15. Fraunhoffer

    Three Fine Craters

    Pleased to find Hadley after a bit exploring and searching (and getting distracted) and something around the area of the Apollo 15 landing last evening.
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