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Uranium235 last won the day on November 14 2017

Uranium235 had the most liked content!

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About Uranium235

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    Main Sequence

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  1. Rolling shutters are a feature of interline type sensors, and shutters are used for full frame transfer sensors. Its all about the speed of which the image is read from the sensor (interline = fast, full frame = slow) http://www.optique-ingenieur.org/en/courses/OPI_ang_M05_C06/co/Contenu_07.html http://www.optique-ingenieur.org/en/courses/OPI_ang_M05_C06/co/Contenu_09.html
  2. But, to really test it I need to use the KAF8300 camera - and try and get the same performace Ive had previously. Note to self: Get a finderscope....lol
  3. Mod seems to work alright slightly better spacing and more diligent focusing required (ie: 2/3rds focusing). But, for just two hours - it aint bad I guess
  4. Really, to get the best out of the lens you have to get the spacing to it focuses as close to infinity as possible. In the end ive had to add a whopping 4mm to the spacing to get it close (with a filter), without a filter it now focuses exactly on infinity.
  5. Im hoping to test it tonight, partially cloudy but thats close enough for me...lol.. Still not sure on the spacing, Ive left it 0.5mm short for the moment and will add delrin spacers if required.
  6. Yay! Scumbag College
  7. Ohhh yes..... Its done. Pro job, and hopefully soon to be commecially available if there is enough interest: Oh btw, the tripod mount for the lens cost me something like 12 quid... amazon bargain...lol. It just needed padding out with some sticky back velcro and its pretty snug now. The whole arrangement is now simplified to screw fittings, and its rock solid.... no droop.
  8. Measuring fwhm on one star only measures it for that particular area of the corrected field. You need to take the whole field into consideration when focusing. That's why it's a bit of a compromise at times
  9. The corners on the pacman are much improved. That leads me to think that the focus can be tweaked slightly to improve the overall field. One thing I used to do is use a ROI box on the offending corner (for quick loop), take an exposure, then tweak the focus very slightly.... "are the stars better or worse?", if not, go the other way... if yes - check the other corners to see if youve knocked anything out of focus - if its still good, youre ready to rock. Sometimes its bit of a compormise. It takes a bit of time to do, but its worth it.
  10. The right hand side of your images displays out of focus stars. This also corresponds with the master flat you posted earlier. Whether that is due to droop in your imaging train, I dont know. But an idea would be to test the lens on a DSLR and take some flats with that - if you get the same vignetting pattern, it will be the lens. If not, then you need to look at the way its attached to your astro camera as to what is causing it.
  11. Update on the lens mod: Should be a week, maybe two at tops. Once its back I'll have a better understanding of how much spacing Ive got to fill. I want it to be as close to the infinity stop as possible (in order to get the best corrected field).
  12. Might be worth upgrading to the ccd cls filter. It has a harsher cutoff and slightly better transmission.
  13. Fashionably late to the party Just booked, Fri & Sat night.
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