Finder-scope Issue

[gsfergy]

Okay I just bought a Celestron Nexstar 8SE and I'm three nights into learning how to use it. I've had some luck, but not much and I got to thinking about whether or not my finder-scope is aligned properly with what the telescope itself is seeing.

So I set up the scope on my kitchen table. I opened the blinds and picked a stop sign about 500-700ft away from my scope and found that the scope displayed the stop sign in crystal clear focus BUT the finder-scope was WAY off!!!

I corrected this using a screwdriver and the adjustment knobs, but I can't seem to perfectly get the red dot in the finder-scope on the stop sign. It's literally just to the right a tiny bit. I can also adjust and end up with the red dot just above the stop sign.

Will this be a problem for aligning at night?

My thought logic - I can never get the red dot in the finder-scope to align perfectly with what the scope is seeing because the finder-scope is mounted above the scope. You can't have both pointed precisely at the same thing!!!

Thoughts?

[oldpink]

best thing you do is find an easy target, Jupiter is a good one as its bright
get it in the main scope by trial & error then adjust the finder scope to center, I find that works for me if mine is off due to being moved when setting up or stripping down
moon can be a good target as well for setting up in daytime

[astronymonkey]

If the dot is to the left of the stop sign then place it to the keft of the object at night.

it sounds near enough to work as long as you remember the offset needd.

red dot finders are always difficult to get bang on anyway.

cheers

[Peter Drew]

If you run out of adjustment before the red dot is lined up, the best thing to do is to reset  the adjusters to mid position then slightly loosen the base of the red dot assembly and move the whole thing in the required direction. Once there, tighten the base again. You should then have enough travel either way.

[baggywrinkle]

I had the same issue with the finder on my 6SE.

In the end I made a shim of thin card, I used a business card, and put it under the rear part of the adapterr that the RDF is mounted on, the visual back side. It then allowed me plenty of adjustment.

Several other folk on this site have done the same.

Welcome to SGL and good luck.

[gsfergy]

Thanks all

[Charic]

gsfergy.......Hi, ..500 feet seems ever-so close. If you can focus on something a couple of miles away during the Day, then try to re-align your finder, you may have better success. Failing that, shim the mount as suggested.

The finder and telescope should point at the same thing at distance.  Also noted you "opened the blinds", are you looking through an open window or double glazed? Although you said the telescope is crystal, the finder may not like looking through the same substrate! anythings possible.

The 3 - 5+ mile  target  outside somewhere, is your best option for  matching finder to telescope.

[gsfergy]

Charic - never thought of that! The window was not open and it is a double-glaze window I was peering through. So that might also be part of the issue, sounds like I need to get outside this weekend and pick a very distant object and re-align my finder-scope! I will report back.

[Charic]

.........There is a recent thread where someone admitted to seeing double,  and they were looking through double glazed glass!  But your telescope seemed to be ok, but you never know, the finder just might be  being awkward. Nothings simple with this hobby? I had a Telrad, great with my glasses on, almost triple vision of the reticle without glasses, and I don't wear my glasses looking through the telescope. You need to try everything and anything.

heres that thread! http://stargazerslounge.com/topic/213463-its-probably-obvious-but-if-it-helps-1-person/

I hope you get it sorted. If not, someone else will have something for you to try, SGL is good for that. Take care.

[gsfergy]

it seems silly that i invest this type of money in a scope that now needs a shim to align properly... ugh... oh well...

[Charic]

..........maybe not required, remember, your generally  viewing things that are over 238,900 miles away, and that's only the Moon for starters.  You really should focus and set up any finder scope at some considerable distance away,  and best during the Day. There may be some other issues, which no doubt, someone else here will help you with. You'll get it sorted.

Your manual says point the telescope at a distant land object, it gives a telephone pole as an example, but a Church spire miles away would be the favoured option. Centre and focus the object with your 25mm eyepiece.  Once that is complete, power on your finder-scope, and by using the up/down - left/right adjusters, place the red alignment dot directly over the centred object. Don't forget to power off the finder-scope once completed! Once that's all done, you will still have to set-up and align the telescope, to the Pole star/ Earth's axis,   then carry out the star alignment, part 8 on the hand Control Guide............have fun!

[gsfergy]

Success!!! The finder-scope is aligned well enough from my daytime experiment to do some viewing tonight, but I stayed away from trying the StarAlign and did everything manually tonight. Moon, Jupiter and Mars were a success using the finder-scope! But I'm convinced further minor adjustments will be needed, but that's part of the hobby in my opinion, as long as I'm continually learning!

Thx for all the help

[Carina Lass]

Mine's a bit off too - but I can compensate - oh we're talking about finders......

[Charic]

gsfergy.........well done in getting some success,  and were always learning

[AlexB67]

Never felt the need to align a finder during day. Using  Polaris, an object effectively at infinity and barely moves is perfect for the job

[Charic]

........ agreed, but not the brightest target up there,  but like you say, it doesn't move. Some folk cant see Polaris? As a test, my neighbour was just outside with me,  she  cannot see Polaris with her  own eyes.  Were standing right underneath Dubhe in Ursa Major. ( one of the guiding Stars) I let her peek through the 7x50s. She didn't realise there were so many Stars up there? At least Polaris is slightly remote to  its surroundings, which helps to isolate and  identify it

[JimmyC]

Remember that star light and other celestial objects' light tends to infinity - The light is assumed to pass us at a parallel angle. Stop signs are another matter as they are merely metres/km away. The light from these is not parallel so you can't really adjust your finder to this. When it's next clear, just focus on a simple low magnitude star, and follow it into view with the finder. You should be laughing.

[Myopicus]

Mine's a bit off too - but I can compensate - oh we're talking about finders......

Cheeky!