Skooby Posted January 19, 2014 Share Posted January 19, 2014 Hi guy I'm going to make my own solar filter but not sure how much I should buy as it's quite expensive. My question is how much do you think I'll need for a 10" scope 250pds? Does it all need to be covered or will an a4 baader solar sheet be enough thanks Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Kirscovitch Posted January 19, 2014 Share Posted January 19, 2014 I'm not sure how big the a4 sheet is but you will want enough to cover the entire aperture. Leave any sort of gap to let the light in and it will be dangerous to view through. Link to comment Share on other sites More sharing options...
Skooby Posted January 19, 2014 Author Share Posted January 19, 2014 That's what I thought is 8 inches wide and around 11 inches long and that's £18 on flo and for the next up it's over £50 no in between roll crazy. Thanks though. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
RT65CB-SWL Posted January 19, 2014 Share Posted January 19, 2014 Hi Skooby,Have you considered an off-axis solar filter?In other words, does your end cap/cover have another smaller removable cap?If "Yes!", then that maybe your best option. Also when making your homemade solar filter, it is recommend you do not have the solar film perfectly smooth. I cannot remember the reason for this as it does not cause any degradation of the 'final' view. Link to comment Share on other sites More sharing options...
Bizibilder Posted January 19, 2014 Share Posted January 19, 2014 Just make one as big as you can from a sheet of A4 film and use that or, maybe more complicated, make one off-axis about 4" in diameter - so the light passes through the secondary spider arms. With Solar viewing it is the heat from the Sun itself that mucks up the atmosphere making the seeing bad. It is a rule of thumb that 4" aparture will allow you to see everything that a larger aparture would. i.e. the image is atmosphere limited rather than aparture limited. Link to comment Share on other sites More sharing options...
Peter Drew Posted January 19, 2014 Share Posted January 19, 2014 You should be able to make an off-axis mask with an apertue of 3.5"-4" that will fit in the unobstructed path between the spider vanes. This would be an ideal white light aperture and leave plenty of film over for a replacement in due course if necessary. Link to comment Share on other sites More sharing options...
ramstar Posted January 19, 2014 Share Posted January 19, 2014 You might want to check the integrity of the film before you start on your filter. I didn't and after quite a lot of time, effort and a few quid spent in making it, I found it was riddled with pin holes so ended up binning it. Not sure if they were due to something I'd done or not, even though I thought I was being careful all the way through the process. I was not a happy bunny I can tell you! Link to comment Share on other sites More sharing options...
wookie1965 Posted January 19, 2014 Share Posted January 19, 2014 How about this insteadhttp://www.365astronomy.com/solar-filter-for-250mm-newtonian-telescopes-p-2952.html Link to comment Share on other sites More sharing options...
Skooby Posted January 19, 2014 Author Share Posted January 19, 2014 Thanks for all your replies guys some really useful information I've googled the off axis filter and It doesn't look to hard to make. Thanks for that. And wookie thanks for that link wow that's gotta be the cheapest I've seen that is tempting I must say once again though thanks all. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Peter Drew Posted January 19, 2014 Share Posted January 19, 2014 Perfectly OK, the main caveat from a performance point of view is that 10" aperture is rather overkill for solar viewing. You could of course add a further outer smaller off-axis mask without filter film to the 10" filter when conditions don't support the main aperture. Link to comment Share on other sites More sharing options...
wookie1965 Posted January 19, 2014 Share Posted January 19, 2014 I was searching for solar film for mine 150p and making my own when i came across that site for mine its only £32 so i think its well worth it. Link to comment Share on other sites More sharing options...
Chris Rowland Posted January 19, 2014 Share Posted January 19, 2014 When I made a solar filter for my NS11 I made an off axis filter of the maximum size that would fit between the edge and the obstruction. IIRC it was an 80mm circle. I made two disks of foam board with a hole in them, held a square of film to one with double sided tape then fitted the other with more double sided tape. Lots left over from and A4 sheet for binoculars, small scopes etc.Chris Link to comment Share on other sites More sharing options...
Skooby Posted January 20, 2014 Author Share Posted January 20, 2014 Thanks guys I'm gonna give one way a try or buy the one from 365 astronomy but looking at that one on 365 astronomy the edges look quite thick if I could make one and have the edge coming in just over 2 inches I could then do it out if the a4 sheet so that would mean that about just over 71/2 inches of solar film will be showing. Do you think that will do? Thanks. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Sammyb Posted January 20, 2014 Share Posted January 20, 2014 here is a link that contains a photo of the one I made out of plywood and card and solar film.http://stargazerslounge.com/topic/156642-solar-fiter-sw-200p/?hl=%2Bsolar#entry1584387 Link to comment Share on other sites More sharing options...
JB80 Posted January 20, 2014 Share Posted January 20, 2014 I made one up out of some boxes left over from Christmas and some rippled cardboard.Works a treat. Link to comment Share on other sites More sharing options...
Skooby Posted January 20, 2014 Author Share Posted January 20, 2014 Sammyb that looks good looks pretty straight forward thanks for the picture. And jb80 thanks for the pic and what size is your scope and what size film did you get? Thanks. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Bizibilder Posted January 20, 2014 Share Posted January 20, 2014 Safety note!! Don't forget to remove your finder scope or make a filter for that as well. Link to comment Share on other sites More sharing options...
RT65CB-SWL Posted January 20, 2014 Share Posted January 20, 2014 I made one up out of some boxes left over from Christmas and some rippled cardboard.Works a treat. P1010158.JPG P1010161.JPGVery colourful! - you will not loose that one! Link to comment Share on other sites More sharing options...
Joseki Posted January 20, 2014 Share Posted January 20, 2014 I think I'd rather make my own or pay a little extra for one like http://www.firstlightoptics.com/solar-filters/astrozap-baader-solar-filter.html which includes the screws for extra security. Really it's not going to come off with the 365 one but I'm paranoid. Link to comment Share on other sites More sharing options...
Skooby Posted January 20, 2014 Author Share Posted January 20, 2014 Thanks yeh I'll also make a cover for the finder scope. Yeh I'd also like to make my own but it is scary if it came off or something that would be the last thing i see outta that eye!! Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
JB80 Posted January 21, 2014 Share Posted January 21, 2014 Sammyb that looks good looks pretty straight forward thanks for the picture. And jb80 thanks for the pic and what size is your scope and what size film did you get? Thanks.Sent from my iPhone using TapatalkHi Skooby,This is only a 6" filter, you could easily make it to be a 6" one from the A4 sheet you would just need to cut the cardboard rings to suit. I followed this set of instructions if it helps... http://www.baader-planetarium.com/sofifolie/bauanleitung_e.htmI ended up with a roll for Christmas but I wanted the ND3.8 which I could only find in a roll and it's only good for use with a camera so you can't observe visually using the ND3.8. Link to comment Share on other sites More sharing options...
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