Homemade Double Sided Solar Filter for Refractor Telescope and DSLR

I modified my DIY homemade solar filter for my DSLR to add a side that will slip snug over my Meade 285 refractor telescope. You can check out my previous post about how I made the initial filter, but it's basically a bunch of poster paper and tape around a $10 square of black polymer.

Double sided solar filter fits on both telescope and DSLR lens

I only have one sheet of this black polymer stuff, so I made a double sided filter that fits on both. Look, it still fits on my DSLR 300mm lens.

Double sided solar filter on DSLR camera 300mm lens

I wasn't even planning on doing this project today, so zero planning went into it. It started when I was cleaning out a closet and found this cardboard mailing tube that had some posters in it. It looked like a good size for a solar filter that goes over the telescope. I tried it out and I was right, this 3 inch cardboard mailing tube was a perfect fit! A little snug but easy to get on and off.

Found out the tube was a perfect size!

Measured where to cut

Cut the cardboard mailing tube with a large kitchen bread knife

Kinda rough but it did the trick!

So next I took the existing filter that I made previously and I taped the tube to the other side. I wrapped another layer of tape around the outside to hold the other tape in place, and then guess what, I taped it some more.

Modifying my home made DSLR solar filter to go on my telescope. This 3" mailing tube is a perfect fit! I hope it works and I don't blind myself 🔭👀

A video posted by Eric Teske (@ericteske) on Oct 9, 2016 at 7:46am PDT

The end result is this totally low budget totally makeshift solar filter. Fabulous! It still only cost me about $10 to make, and all of the real cost is tied up in the little sheet of black polymer.

$10 DIY Solar Filter for DSLR Camera

I made a solar filter that fits over my DSLR lens for $10 and it only took me about 10 minutes. I made it to photograph the partial solar eclipse that will be visible for much of the western and Midwestern US on October 23, 2014.

The only real cost was for the 4"x4" sheet of Thousand Oaks Optical black polymer solar filter. You can by it in bulk to bring the cost per square inch down, but this 4 inch section is more than enough for what I'm making and was about the same price as a pack of 5 solar eclipse cardboard viewing glasses. I chose this over Mylar because it is supposed to make the sun appear a more natural orange rather than blue-green.

I've read other posts about making ones out of CDs or x-ray paper or whatever - I wouldn't skimp on this just in case. It's just $10 and shipping took 1 day, don't mess around, just get a sheet of the good stuff. It still beats a threaded camera filter for $50-$65 using the exact same black polymer.

Final product fits snug on lens and holds the black polymer filter in place

This is the final product, and the photos below show the sequence of making it out of tape and a black school folder.

Thousand Oaks Optical black polymer solar filter arrives in the mail

Black polymer solar filter 4"x4" sheet

Used the lens base cover to approximate the size of the viewer

Traced it with a pen and cut it out

Made 4" squares on a school folder

And cut them out

Cut a strip of the folder and rolled it up to wrap around the lens for size

Wrapped it around and taped it to size

Cut wings on one end and bent them flat. Taped the flaps between cardboard and folder

Flaps are taped down to cardboard and folder taped over that to cover

Put the solar filter uncut between the sandwich made of folder and cardboard

Taped all around to hold in place. Now my solar filter is uncut and un-damaged and held in place

DIY Homemade iPhone Telescope Attachment Adapter Mount

I love taking photos of the moon through my telescope with my iPhone, the camera is really small but sharp and high resolution. The hardest part is keeping the camera centered over the eyepiece. You can try snapping a pic handheld, or constantly adjusting a tripod pointing down through the eyepiece, but if you really want to get a good photo you need to have a mount attachment to keep the camera steady. There are retail iPhone telescope adapters available ($50 to $70), but making one out of junk can be fun too!

DIY iPhone telescope attachment adapter mount thing!

I used the "random crap around the apartment" approach, so first I'll explain the components in basic terms so that you might find something suitable if you don't have exactly the same things lying around, and then I'll show you how I made mine.

You'll need:

1. A platform - something about the size of your phone that is sturdy, flat, and light weight so that it can hold the phone up without bending. In my case, I used a plastic insert from an Apple mouse package. You could also use wood, other bits of plastic, or a long metal bolt.


2. A cup or clamp - something to go over the eyepiece or clamp around the eyepiece that attaches to the platform. In my case, I used a plastic medicine bottle. You could also use a film container (if those still exist), a cap from a travel size shaving cream canister, or anything about the right diameter and long enough to go down the eyepiece a ways. 


3. Adhesive - some way of attaching the cup to the platform. Hot glue would probably work best, but I used sticky dots and it worked just fine. iPhones don't weigh that much so it shouldn't be a huge deal.


4. A hole - you'll need a way of cutting a hole in the cup. I used kitchen scissors and it was sloppy but fine. A drill would make it nice and neat, but do what you can.


5. Snug-ification - you'll need a way to make the cup snug around the eyepiece so that it can hold the DIY mount onto the phone. If you're using a clamp instead of a cup, you'll need a way to tighten the clamp. If you're using a cup, you just need something with a little bit of give to go around the eyepiece. I used paper, you could also use foam, cotton, cardboard, or whatever.


6. A seatbelt - you'll need some way of attaching the phone to the mount itself. My regular phone case has some silicone on it, so if my scope is relatively horizontal it can grip a little bit on its own. For more vertical angles, I use a bit of tape on the back of my phone and it's fine. You could also use a rubber band, a neoprene sleeve, a wire, or make the mount out of an old iPhone case itself.

I found a plastic insert from an Apple mouse package, and a generic allergy medicine bottle about the size of my eyepiece

I cut the medicine bottle in half and cut a hole in the bottom. I glued it into the corner of the Apple mouse package insert

I made sure the hole was big enough to fine tune my iPhone placement with different eyepieces if needed

I used glue dots, but any kind of strong glue will work. Don't get glue on your eyepiece!

The bottle was almost the right size, but I stuck paper in the plastic cup for a snug fit

The plastic cup is deep enough and snug enough to hold the iPhone out horizontal without bending

I used some tape once I had the iPhone in the right position over the eyepiece

And I used the Apple headphones as a shutter release for the default camera app in video mode

Here is a screenshot of the video, not bad!

Here is the final product after stacking 15 sec of video in Registax (461 frames of AVI) punched up a little with a high pass layer in Photoshop

DIY Paper Bahtinov Focusing Mask

Since my camera doesn't have live view, I have to focus through the little viewfinder. I figured a focusing aid might help me out. I read that a Bahtinov mask could help take some of the guessing out of trying to focus. I found a helpful post about making one yourself, and even a Bahtinov Focusing Mask Generator. I didn't have any black plastic, but I tried my best making one out of paper and it actually wasn't too bad.

I printed the image from the Bahtinov Focusing Mask Generator on cardstock

...and cut out the white spaces...

...which took me about 20 minutes.

Then I cut out the disk itself.

I wrapped paper around the end of my telescope and taped it for size, then attached the focusing mask with tape.

I figured it doesn't really matter if the white or black side faces out. Looks kinda badass.

Even this paper one works in principle - it "produces three angled diffraction spikes at the focal plane of the instrument" (Wikipedia). The problem is that my focuser sticks and jumps, and I only have a course focus. Knowing where focus is doesn't help if you can't accurately make adjustments - I just shoot past it in both directions but can't fine tune it. Oh well, not a bad little project!

DIY iPhone Thermal Jacket: I like the way you work it (no diggity) I got to bag it up

Blue skies all day and then thick cloud cover as soon as I got off work. Typical. I saw a break in the clouds so I wanted to run out and try some quick iPhone star trails using the Night Cap app.

The session didn't turn out so hot, but at least my camera didn't get too cold! I put a freezer bag over my iPhone on the tripod, cut a hole in the top corner for the camera to peak through, and taped the bag in place next to the camera lens.

A little cloudy, but at least my lines are straight thanks to the tripod mount

I started shooting back to back 1 sec photos at ISO 3200, and after 20 min or so my battery had only dropped 2% (better than the 45% drop in 5 minutes last week). It's slightly warmer tonight (20ºF instead of 10ºF) but I attribute the improved battery performance to my little baggie windbreaker.

An added bonus, when I brought my phone back inside, condensation formed on the outside of the bag instead of on my phone directly! Neato!

DIY iPhone tripod mount for $1

Following the directions in this YouTube video, I was able to make a super simple and super cheap tripod mount for my iPhone. It's not very sturdy, it seems like even a breeze would make the camera shake, but it's better than trying to lean it up against something or setting it on the rear window of your strategically parked car!

The nut is 1/4", the rest of the pictures are self-explanatory...