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About Ross1204

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  1. Hello, It is suppose to be clear tonight but thinking that at 70% Moon phase and it being close to the target is there any point? Does anyone have any experience with shooting H-alpha with a similar set of circumstances? Ross
  2. Thank you all for taking the time to help, very grateful. So, I reckon next time the clouds break giving me a chance to get out there I shall stick to ISO800 and just shorten the exposure times. I have previously exposed at ISO200 for 180s and the resulting data was full of noise and lacking detail compared to all the other nights. Hopefully shortening the exposure times does not kill the camera's ability to pick out the faint details in DSO's. Thanks again. Ross
  3. Thank you all so much for replying and helping me understand what was causing this change in the histogram. Every single point makes perfect sense, relieved man! With that said what would be best way to shoot going forward? Lower ISO? Shorter exposure time? Purchase filter? I have generally been really happy with 3min subs at ISO800 ,but now seeing a overexposed histogram with these settings does make me think I may need to change it up, cos last time out I didn't really get much usable data. Thanks again Ross
  4. Hi, I'm posting this question in the hope I can gain a little clarification on what causes the histogram on my exposures to gradually move further to the left throughout the night. I have saved a few screenshots below which show the clear shift. My current thinking is that it could be either light pollution, accidental setting change in the camera, thin cloud (could still see stars though) or bad seeing conditions? However the last image though is using the same ISO and exposure length as the two before but as you can see the histogram is way over to the right becoming too overexposed. This one is a little more confusing in some ways as not sure why as the above stated settings are usually fine. Any advice would be much appreciated? 1-11-18 - 21.53pm - Sussex - Pointing South/South East Histogram - 2-11-18 - 2.45am- Sussex - Pointing South/South West Histogram - 8-01-19 - 7.08pm - Sussex - Pointing South/South East Telescope - Skywatcher Mount - HEQ5 Pro Camera - Canon 700D (Astro Modified) - No Filter
  5. Firstly wanna thank everyone for taking the time to comment and help me with this question. I manged to luckily get the scope out and test the mirror since the scratch when cleaning and I don't believe there is any noticeable difference thankfully. The only thing I have noticed is that there is a difference in the diffraction spikes when you compare a picture from before cleaning and collimation to after. I have posted two pictures below to show the difference of the center point of the star, the one after cleaning has a noticeable cross in the middle which I am thinking is down to bad collimation. Is that correct? Ross
  6. Hi, Does anyone happen to know whether a small scratch on the primary mirror of a newtonian would show up in a DSO exposure? Was trying to clean the mirror and noticed a small scratch which I don't believe was on there before the cleaning. Not really a clear night in sight to check so just thinking if anyone could shed some light on the situation. Most of the googling I've done has shown posts where people have suggested it shouldn't be a problem but they are predominantly referring to visual astronomy. I am thinking that the greater sensitivity of the camera sensor is more likely to show up the problem. Thanks Ross
  7. Thank you for going to the effort to get this picture, very much appreciated. I can definitely see the benefit of circulating the air inside the scope its just I can't help but think I will also need some heat somewhere. Thank you for going to the effort to get these pictures, very much appreciated. I have never seen a secondary heater like that before so has definitely opened my eyes and I'm sure the wider community who may stumble across this thread. Looks nice and neat also with the power cable firmly secured to the spider vane, zero interference to the final image. I have emailed Kendrick to see what they can do but I believe it is their Thanksgiving holiday so hopefully get a response when they are back. Looks like it might well need to be custom job because the secondary on the 130pds is obviously on the smaller size and from what I have seen most of the off the shelf secondary heaters are too big.
  8. OK thanks for letting us know it can work via the main OTA opening. The thought of not having to remove the camera is good to know, although it is a damn sight easier to see how dewed up the secondary is if you remove the camera. I guess it would help to let the scope settle for 5mins or so to let any tube currents equal out also. Thanks for reply. Now assuming the fan wouldn't provide any heat to aid dew removal just the very fact air is circulating in the tube can be enough? Maybe OK for mild dew accumulation but not heavy build up? Also not entirely sure how I would fit such a fan, Google to the rescue..... Would I assume you placed the dew strip over the thicker white section as surely the spider fixings get in the way in getting the heater closer to the secondary? Kinda like this picture.
  9. Thanks for reply. Thanks for providing the link I shall definitely take a look. I have never really made anything like that before so hopefully its not too steep of a learning curve as would like something pretty sharpish. Thanks for reply. Now when you say 'front opening' of the OTA is that just positioned like a standard dew strap around the circumference? Or located somewhere around the secondary? Thanks for reply. Yeah I have also looked in to getting one as really cheap and already have the ability to power outside. How do you actually use it though, do you direct the heat in to the front of the scope or down the focuser directly at the secondary? The thought of removing the camera to directly target the secondary seems like it could get boring quick, not so much maybe if your doing mostly visual as removing a eyepiece isn't as much of a big deal. Thanks for reply. Ok that sounds interesting, I like the idea of powering with just a standard 9v battery. With regards to the picture it is entirely up to you, don't feel you have to if too much hassle.
  10. Hello, So as the title of the thread says I am consistently suffering from bad dew formation on the secondary mirror (Skywatcher 130pds) which has stopped multiple nights of imaging after barely an hour or so. I would like to think I have done a fair amount of research on the topic but unfortunately I am still unsure of how to deal with the problem. I initially brought a dew shield which I believe has slightly prolonged the inevitable for a short while but unfortunately has not solved the problem. After the shield didn't help I brought a wrap around dew heater (https://www.365astronomy.com/dew-heater-strip-for-newtonian-telescope-secondary-mirror-small.html) which is unfortunately too big for the secondary mirror stalk. I have also seen that Kendrick and some others do stick on dew heaters which are glued to the secondary itself but again I believe the mirror on the 130PDS to be too small for their smallest product so yet again this is not the correct approach. So after these failed options what is left for me to try? Maybe a dew strap around the OTA at the front? Look in to making my own strap? Lastly I have read people use a 12v hairdryer to remove dew but as I am not doing any visual astronomy I don't think this would be a good solution as removing the camera would mean re-focusing every so often wasting imaging time. Any help would be much appreciated as this problem is causing quite a lot of bother by ruining many imaging sessions. Ross
  11. Unfortunately I don't see an observatory on the cards anytime soon so still scouring the internet for the best solution for the 130PDS. There are a few different heater options for the secondary on Newtonian telescopes but I think the secondary on the 130PDS is too small for this Kendrick heater. I did read on one retailers site they stated the minor axis of the 130PDS to be 47mm which is obviously too small for this heater unfortunately. So with this being said you also have the option for something like this. https://www.teleskop-express.de/shop/product_info.php/info/p8571_AST-Heater-for-glued-Newtonian-secondary-mirrors-with-holder-D-31-mm.html But again I am unsure whether this is the right size and would be suitable. I currently own this Dew Shield but unfortunately the secondary has still slightly fogged up, granted way less less than without it so definitely helps a bit. https://www.telescopehouse.com/accessories/dew-removal/omegon-5-dew-shield-145-165mm.html Ross
  12. OK that make sense. I always find it hard to see the mirror fog on the reflection from the primary but I generally know something is wrong by the histogram slightly moving more to the left the worse it gets.
  13. Thank you for the reply. Out of interested if I were to use a hairdryer or heat gun do you need to remove the camera and direct low heat directly on to the secondary or can you just direct the air straight in to the ota? Also how long roughly would you say you need to use it to clear the mirror? Ross
  14. Hi, I have recently started to get the secondary mirror on my 130pds dew up pretty fast and am wondering if one of these heaters would be suitable? I am just a little unsure on how to measure the stalk as there are two sizes available. I also already use a dew shield which has helped but not stopped the problem on the bad nights. https://www.teleskop-express.de/shop/product_info.php/language/en/info/p8593_AST-Heizmanschette-fuer-geklebte-Fangspiegel-mit-Halter-D-50-mm.html https://www.teleskop-express.de/shop/product_info.php/info/p8571_AST-Heater-for-glued-Newtonian-secondary-mirrors-with-holder-D-31-mm.html The product also states for a 'glued secondary mirror' is that what the 130pds has? Any help would be much appreciated. Ross
  15. Thanks Jim for the help in getting my thinking a little clearer with is. Do you leave your camera outside or place it somewhere inside facing out? Just wondering if you get any reflections if its inside. Ross
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