I just received the A4 sheet I purchased the other day, (was meant to be for the solar eclipse, but I guess that idea is out .)
I am just wandering how people are actually using this stuff. I know that you can cut it up, but how are people attaching it to things in order to use it safely.
This sheet didn't come in a postal tube or anything, so that idea is out. I would like to create something that is re-usable and more importantly safe.
Let me know what you guys do, and hopefully post some pictures.
I have an 8" newtonian, but I think I am just going to use the off axis hole on the end cap. I also have a 102mm refractor and I will also use it to make filters for the view finders as well, assuming there is enough material.
I have made two filters for my 8" SCT and one filter for my 12" Newtonian with a sheet of the Baader film.
I used cardboard purchased from a newsagent to make them. The cardboard is about 1mm thick. I need one sheet of the cardboard to make a filter for my 8" SCT, 3 sheets for the 12" Newtonian.
I cut strips of the cardboard 5cm wide along the long side of the cardboard. I use 5 strips for an 8" and 8 for a 12". I then use packing tape (that ugly brown stuff) to join the strips together into one long strip 5cm wide.
I then wrap this tightly around end of the telescope where it is going to fit and join the end with the packing tape. Then I remove the ring of cardboard and wrap tape around it in about 8 places to hold the coiled cardboard ring together.
I then put it back on the telescope to make sure it is a good fit. I like it to be so tight that it is quite hard to get it on and off.
Now you measure the outer diameter of the cardboard ring while it is attached to the tube and draw two circles of that diameter on the remaining cardboard. At this time I mark off six points around the perimeter of each circle with the compass. At each of these six points on both circles I roughly draw a tab about 3cm long and 2cm wide to secure the disks to the ring.
For a full-apeture filter I now use a compass to draw circles for the apeture of the filter material. I leave about 2cm around the edge. I then cut these out with a knife and cutting board.
Next I cut out the two disks each with 6 tabs. I use a stanley knife.
If making an off-axis filter, I now line up the two discs so that the 12 tabs are evenly spaced around. Now mark the centre of the off-axis filter circle with a pin that you push through the top disk and into the second disk. Also place some matchmarks so you can line the discs up in this position again later. Draw the circles for the off-axis filter on the two discs and cut them out with a knife.
I then put double sided tape in strips around the filter apeture and secure a piece of the filter material to the disc then cut away the excess. The material should look relaxed, not streched. I try to get the material flat, place the disk on top and press down around the edges to secure the tape.
Now put more double sided tape on the other disc in order to secure the two disks together. Using the match marks made eariler line up the disks and press them together.
Finally, I secure the disc to the ring with packing tape.
Ah, thats better.
Can I suggest when you make the off-axis for the 8", it somehow accepts the same filter as the 102, as this will save you making two. I have made them as described, using cardboard and they work well.
Lately though I used PVC pipe fittings, and also spun a couple up from Rimu (a New Zealand Native timber).
Either way try to get the film flat, but if you end up with a wrinkle or two, fear not, it doesn't make much/any difference.
You do end up with wrinkles if the film is relaxed. This is good
I'd make filters for both both telescopes. I'd also make them for the finders and, any binoculars and even some simple glasses for naked eye viewing.
The more equipment you have equipped with filters, the more of your equipment you can use during the event. If the weather co-operates, I intend to photograph the eclipse through the 8" SCT while looking visually through the 12" dob, binoculars and naked eye (through filtered glasses).
To make a finder/binocular filter is much easier. These don't have to be perfect so I don't spend a lot of time on them.
I first cut a strip of cardboard about 3cm wide and about long enough to wrap around the finder/binocular objective 1 1/2 to 2 times. Wrap this around the finder/binocular objective and secure the end with packing tape to form a ring. Then I cut a second strip of cardboard the same length as the first but about 1.5cm wide. Wrap this around the first ring and secure the end with tape. The outer ring should slide easily over the inner one. Take the outer ring off.
Now cut a square of the filter material, put it over the first ring (still on the objective) and slide the second ring over to secure it. Roughly cut away excess filter material and use packing tape to secure the whole thing together.
Make sure there isn't too much damage to the filter material. If any pinholes are visible (and are stressing you) they can be covered with a black felt marker pen.
can you laminate this stuff? i was thinking about making a solar filter out of this stuff, but i'm apprehensive about breaking this stuff but it's cheaper than buying a proper solar filter ($190 for my ED80 )
You're not supposed to laminate it. Just use a single layer. The material must be relaxed, not streched for the best resolution.
The double sided tape makes it easy to capture the material in a relaxed state without risk of damaging it. I showed this in the glasses pictures.
The beauty of the film is that you can make filters for everything. I got a 1/2 square meter sheet a few years ago. I've made all these filters and more and still have some left over
awesome, well i'll be incognito for the solar event on thursday, and even then it's raining here anyway, so i'll look into it out of necessity next time round
Well mine certainly don't look that professional...but I think that what I have come up with will work. Mind you, I had to deal with the whole trial and error thing so I will have to buy some more cardboard to do the 8" off axis filter.
Well I had a problem with dust causing any images to have spots all over it. Trying to remove the dust did not want to work at all and the higher the magnification the worst it was; for visual it is fine as the dust doesn't bother me.
However, I slipped the filter in the above pictures over my 600mm mirror lens and was able to take a couple of good shots; at least dust doesn't show up. Anyway, I have attached them, note the colour has been added through the use of a Photo Filter in CS2 as the plain white wasn't as interesting. I think that this will be a great size IF the clouds break a little tomorrow.
Lets just hope the weather co-operates enough to get an image of something tomorrow.
If you're seeing dust in the view it's more likely to be on the eyepiece than the filter as the eyepiece is near the focal plane. You shouldn't be able to see dust on the filter through the eyepiece (unless perhaps the image is really out of focus).
In terms of seeing dust, this is while I was trying to image at prime focus, so there was no eyepiece at the time. But I reckon the 600mm is going to do the job I want anyway (without clouds that is ).
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