menacegtr Posted February 13, 2018 Share Posted February 13, 2018 High to you all again. It's been a while since i last posted here so i thought i would like to ask you clever people a serious question. I still have my fantastic Startravel 120mm refractor with some very nice upgrades. Anyway, here is what i would like to know. Today i received a solar filter specifically for my telescope, here is the link https://www.365astronomy.com/Solar-Filter-for-120mm-Refractor-Telescopes.html What i would like to clarify is, is it safe to just go outside and attach this to my telescope and secure it, i would use cellotape incase wind might blow it off, and also to remove the red dot finder. Is there anything else i need to do before i use this filter. I would appreciate any further advice from you guys. It may have been covered here before but i just want to make sure you all know what i have and its usage Link to comment Share on other sites More sharing options...
wookie1965 Posted February 13, 2018 Share Posted February 13, 2018 Just check there are no pin holes in it by looking through it at a light source obviously not the sun, then yes fit it to the front making sure covers whole aperture and your good to go. I had one on a 150p reflector I took pictures of the Mercury transit. I now have a lunt herschel wedge for my Tal 100rs. Link to comment Share on other sites More sharing options...
laudropb Posted February 13, 2018 Share Posted February 13, 2018 You are right to be cautious when it comes to solar observing, but if you make sure the filter is intact with no signs of damage, the whole objective lens is covered by the filter and it is securely fitted you should be safe to go. Always remove any finders as you have said. Just a word of warning. You may find it difficult at first to actually get the sun in the eyepiece. You have to point the scope in the general direction of the sun but do not try to sight along the Telescope tube. Look at the shadow that is cast. You then move the scope until you achieve the smallest shadow that you can get. Hopefully a round shadow. Then look through a low magnification eyepiece and gently scan for the sun. This can be difficult at first but with a bit of practice it does get easier. It took me a few attempts the first time I tried. You can get dedicated solar finders which make life much easier but they can wait as I am sure you will be keen to get your first view. Welcome to solar observing. Link to comment Share on other sites More sharing options...
menacegtr Posted February 13, 2018 Author Share Posted February 13, 2018 Thank you Laudropd for your reply. I am glad its ok to use the filter as intended. Is there any need to worry about the eyepieces, do they need a filter on as well, and is there any worry about destroying my diagonal. As i said in my first message, there is nothing on the scope that is standard apart from the tube itself, i don't want to ruin any of my kit, or the telescope. Also is it ok to use my 25mm x-cel and the 9mm. Just need all the info i can get Regards Dave Link to comment Share on other sites More sharing options...
laudropb Posted February 13, 2018 Share Posted February 13, 2018 The image may be very bright. I use a Baader Solar continuum filter, but it is quite expensive. Others use a polarising filter to dim it down a bit. I find the continuum filter gives better contrast, but it does turn the image green lol. I use a zoom eyepiece to find the sun but I use a 5 mm X-cel for viewing sunspots and it works well. Link to comment Share on other sites More sharing options...
Stu Posted February 13, 2018 Share Posted February 13, 2018 1 hour ago, menacegtr said: Thank you Laudropd for your reply. I am glad its ok to use the filter as intended. Is there any need to worry about the eyepieces, do they need a filter on as well, and is there any worry about destroying my diagonal. As i said in my first message, there is nothing on the scope that is standard apart from the tube itself, i don't want to ruin any of my kit, or the telescope. Also is it ok to use my 25mm x-cel and the 9mm. Just need all the info i can get Regards Dave Dave, the filter is ND 5 which is correct for visual and basically reduces the intensity of the sun down to 0.001% of the original brightness and heat, giving an image that is safe to view. It prevents any damage to the inside of your scope, or the diagonals or eyepieces, which is why it is so important it doesn't fall off! So, you are safe to go ahead as described. As mentioned, various filters can help bring out the detail more. The Continuum is very good, although expensive. An OIII or UHC if you already have them can also be quite effective. Given that your scope is a fast achromatic, you will see CA on the sun so any of these filters will have a good effect in cleaning this up as they have a very narrow frequency band. Note that an ND or variable polarising filter will reduce the brightness but not the CA so I think the others are better options for you. Link to comment Share on other sites More sharing options...
menacegtr Posted February 13, 2018 Author Share Posted February 13, 2018 Thanks for all advice, much appreciated. Would my Baader Semi Apo filter be any good in this situation or do i need the filters you have mentioned Link to comment Share on other sites More sharing options...
LukeSkywatcher Posted February 13, 2018 Share Posted February 13, 2018 I'd be worried about the Cellotape. I dont think its strong enough or up to the job. On a hot summer day, the glue on Cellotape could melt and the filter may fall off. Its also not very reusable. Link to comment Share on other sites More sharing options...
menacegtr Posted February 13, 2018 Author Share Posted February 13, 2018 @LukeSkywatcher Yes i see what you mean. The good thing about this filter is, it fits snugly inside the dew shield on st120 if that is what you call it Link to comment Share on other sites More sharing options...
LukeSkywatcher Posted February 13, 2018 Share Posted February 13, 2018 Best not to risk it falling off though. A couple of strips of double sided sticky velcro will hold it in place really well. Link to comment Share on other sites More sharing options...
menacegtr Posted February 13, 2018 Author Share Posted February 13, 2018 Yes i will pay attention to that Link to comment Share on other sites More sharing options...
cletrac1922 Posted February 13, 2018 Share Posted February 13, 2018 Hi Dave Provided you have right solar filter should not be an issue Done same thing with my ED80, and just used electrical tap to secure Recently purchased a glass solar filter, and fits very snuggly With my Skywatcher 10" collapsible dob, just remove small hole cover of the lid, and I just attached Baader solar filter underside of the cover, and observe from there Have attached a couple of pics One is showing solar filter my ED80 Other is of solar eclipse back in 2012, taken with camera android phone, to eyepiece through my dob Have fun your solar viewing John Link to comment Share on other sites More sharing options...
LukeSkywatcher Posted February 13, 2018 Share Posted February 13, 2018 All good advice above regarding safety. The filter you have is all you will need for observing the Sun in White light. You dont need to invest in solar continuum,polarizing filter etc. It blocks out 99.9% of heat, so your scope and eyepieces will be fine. When you get it, put it in place and start observing. A couple of yrs ago i bought a white light Hershel wedge (and filters...............400 euro). Love it, but now i want more. I just recently bought a Daystar Quark (1300 euro) because i want to start observing the Sun in H-Alpha. Link to comment Share on other sites More sharing options...
menacegtr Posted February 14, 2018 Author Share Posted February 14, 2018 Thank you to everyone who has commented, i appreciate all your help. I knew i could count on you for advice 10 hours ago, LukeSkywatcher said: All good advice above regarding safety. The filter you have is all you will need for observing the Sun in White light. You dont need to invest in solar continuum,polarizing filter etc. It blocks out 99.9% of heat, so your scope and eyepieces will be fine. When you get it, put it in place and start observing. A couple of yrs ago i bought a white light Hershel wedge (and filters...............400 euro). Love it, but now i want more. I just recently bought a Daystar Quark (1300 euro) because i want to start observing the Sun in H-Alpha. Regards to you all Dave How the hell was you lucky enough to have that user name then Link to comment Share on other sites More sharing options...
LukeSkywatcher Posted February 15, 2018 Share Posted February 15, 2018 17 hours ago, menacegtr said: Thank you to everyone who has commented, i appreciate all your help. I knew i could count on you for advice Regards to you all Dave How the hell was you lucky enough to have that user name then I made it up. Link to comment Share on other sites More sharing options...
Nyctimene Posted February 15, 2018 Share Posted February 15, 2018 Finding the solar image with the solar filter in place sometimes can be tricky and time-consuming. A solar finder accelerates the process considerably; you can make one yourself: http://www.dd1us.de/Downloads/a collection of solar finder designs 0v6.pdf or you can use the solar finder function of the Red Dot Finder Baader Sky Surfer III. Works like a charm - the front tube section casts a shadow, that has to be made congruent with the front end of the rear section; done within a minute: https://www.baader-planetarium.com/en/accessories/telescope-accessories/finders-and-accessories/baader-sky-surfer-iii-red-dot-finder.html Stephan Link to comment Share on other sites More sharing options...
Mikey0368 Posted March 8, 2018 Share Posted March 8, 2018 I've got a similar question. Is this what I should be getting for my 200mm reflector?..... https://www.365astronomy.com/EMC-S100-Solar-Filter-Size-8.html I've made my own filter for the camera but I'd rather have a proper one for the telescope! Thanks. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.