Smart Phone Finderscope





Introduction: Smart Phone Finderscope

This one is a simple smart phone finderscope attachment for  a telescope to assist one in quickly locating astronomical object.

(This is a quick instructable - I will edit it later but you get the gist of what we did)

We used it on Friday, 6th of Sept 2013  to locate Venus full day light - when the sun was well above the horizon.

The telescope is 100 mm Newtonian, home brewed by Pooja, who is looking at Venus. In the background are (from L to R) Smruti, Mayank, Hrishikesh, Jayshree  and Arunima.

I must say here that Pooja is slightly better than novice - she started observing just about 8 months ago.

At the time of posting this instructable we have not seen Uranus and Neptune but we are confident that it will be a 'damn' easy to do so.

All that is needed is

1. Smart Phone (of course) with sky map installed.
    I am using Samsung Galaxy with Google Sky Map app.

2. A cassette cover

3. A piece of wood - about the length and width of the cassette cover

4. I am using - ball and socket attachment with 20 TPI 1/4 inch bolt for camera.

5. 20 TPI 1/4 inch nut

Step 1: Nut to the Wooden Strip

A hole was drilled in the center of the wooden strip and the 20 TPI 1/4 inch bolt was fixed to it.

Step 2: Wooden Strip to the Cassette Cover

The wooden strip was now fixed to the cassette cover. 

Note: You have to file away the cassette holding tabs on the cover. 

Step 3: Attachment Goes to the Telescope

Now the phone is inserted into the cassette cover - fixed to it by rubber bands and the attachment goes to the telescope --

I had a ball and socket attachment that I could fix to the telescope tube but one should be able to work out appropriate arrangement.

One possibility, that I had used in past is to use ball and socket part of rear-view mirror is a mirror in automobiles or use camera holding part of the camera tripod.

Step 4: Aligning

Aligning is the next part

First the optical finder scope and the main telescope were aligned.

Looked at a distant object through the telescope and then aligned the finder scope.
(you know what to do)

Next we put the phone on a camera mode and centred same object in the square of the screen.

Finally we pointed the scope towards the sun - Use of extreme caution is needed here -
On a paper we first took the image of the sun using the finder scope.

Then covered the finder scope. Put the smart phone on the Sky Map mode and by get the Sun in the centre of the screen.

This done- use the search mode and simply follow it to Venus- and there it would be a nice bright dot in the field of the optical finder scope.



    • Science of Cooking

      Science of Cooking
    • Pocket-Sized Contest

      Pocket-Sized Contest
    • Trash to Treasure

      Trash to Treasure

    We have a be nice policy.
    Please be positive and constructive.




    Oh, that's a good idea - the app is so much cheaper than one of those fancy mounts that find the stars for you (and they strike me as somehow cheating, anyway...).

    Thanks and you are absolutely correct Kiteman -
    In fact even this app I had considered as cheating.

    For almost two years I was thinking - should I make or not to make - then yesterday I gave up on myself - it took me about an hour or so to get it going.

    Have you entered it into the "Build my Lab" contest?

    I wanted to but presently life is far too busy - with fair amount of admin work - I even lost my pro status given to me two years ago. In less then 3yrs I retire and then I will have my own world. LOL

    All you need is a couple of clicks - follow the link I gave, then hit the blue button that says "Enter This Contest".

    thanks a lot - I just did that

    The app doesn't use the camera, it orientates itsrlf by GPS and accelerometers to show what part if the sky you sre facing - point it at the ground, you see the sky on the other side of the planet.

    The eyepiece is fine as well, because the Sun's light is not focused on a surface inside. I have used binoculars to project images of the Sun on several occasions.

    OK, thanks, now I understand. I will delete my comment.

    rimar2000 - not sure what your comment was that you deleted. But as you are a pro let me say here that - I was in a hurry to put this up - gave just bear necessary notes on this instructable thinking that these should be enough for people in the game to essence of this hack.

    I am in this game of astronomy for a long enough time to know how to handle the 'SUN' - secondly I used the camera of the phone for first alignment - in this case I was looking at a far away terrestrial object. And did not use it on the Sun.

    AlphaRomeo, pardon, I didn't understand rightly your instructable. I am a hasty old man, it is not the fist time I make an error like this.