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iPhone Finder?

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#1 daviddecristoforo


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Posted 17 November 2019 - 11:53 PM

There are many options for finder scopes, laser pointers and target type finders like the tetrad and they all are based on the assumption that one knows where to look to find celestial objects. But for a rank beginner I was wondering if there might be a simpler way to find things. So here is my idea (and question)…


I have downloaded some apps to my iPhone that can be used to find things in the heavens. I tried several but I am liking the SkyView one best. I only have the free version at this point but it’s very easy to find things with it, I am wondering if it would be possible to make something to mount the iPhone right on the OTA just like you would a finder scope, something that would be adjustable so that the line of sight would be the same as that of the telescope just like you would do with any other finder. Then you would have a very easy, “pictorial” way to aim the scope.


Any reason this would not work? If it would, it might make it really easy for a youngster to use the scope while learning other more advanced navigation methods.

#2 outofsight


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Posted 18 November 2019 - 01:46 AM

No, and I'll try to sum it up as best I can. There are all kinds of finders, as you said, and they are sighted in to your scope, and you are essentially looking through them to a specific area of the sky, a very specific area. But let's use a laser as an example, you don't look through it, but you do look at the beam and tie it to a specific star or object. You can't look through a phone. If you're off just a few degrees, what you're looking for won't be in your eyepiece. 


But your app is still an important tool, you want to know what you're looking at, and the general direction of things. That's what your phone gives you, the general direction. The general direction is not good enough for finding an object in your scope. Your phone does give you a lot of info, but it probably won't work as a finder for your scope.


Your phone will get you into the general area, your finder will get you into the specific area.


But if you have a phone and a telescope then try it, you'll probably quickly find what I mean. But if it works, let us know, many people have brought this up, and one of these years your idea will work, but probably not this year. Your phone screen would have to be very exact, and you'd have to be able to look through it.

#3 FLT-Astro



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Posted 18 November 2019 - 03:09 AM

Outofsight brings up many of the problems with your idea of using a phone instead of a finder, charts, maps or the like along with a telrad or finder scope. Still more problems exist.


How accurate is your phone at pointing precisely at a celestial object and is it aligned with the axis of your telescope?


If not aligned then you would have to purchase or construct a mount the can adjust the phones camera to match the view axis of your telescope and you might have to re-align it every time you want to use it.


Are other apps more accurate than mine or yours?  I use Sky Safari and Celestron Skyportal.


Another isue is the phone orientation can be affected by certain metals that corrupt the compass.


Still another is the phone’s camera is often in a very wide view so zooming in for more better accuracy might be necessary.  


Maybe a zoom lens on the phone could help, and a plastic or wooden mount that adjusts the alignment to match the telescope axis and is not near the metal scope tube, but even then you’d have to make sure the telescope and other gadgets are not corrupting the phone compass.  


I too am a beginner and I did spend a fair amount of time searching the internet, amazon, eBay, and other areas for information and decided that many others have already tried this and found it wasn’t worth the time and effort. I decided the phone finder couldn’t replace the need for learning the night sky enough to locate constellations, asterisms, named stars, etc.  In a way it’s like the need to know basic math concepts versus just teaching the how to use a calculator.


I often use my phone to find my way or orient myself in the night sky but only to confirm a few stars for alignment, then I rely on my goto mount to point me in the direction and I consult my planisphere and star charts to help guide me to other objects, and still I sometimes pull out the phone to confirm what or where I’m looking.


Edited by FLT-Astro, 18 November 2019 - 03:18 AM.

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