Polar alignment: Finding it really hard to judge how to adjust Alt/Az bolts to move target star

[mrflib]

I'm just moving in to imaging and really need to beef up the quality of my alignment on the NEQ6.

So far I use the EQ Mod method of polar alignment to get it roughly right, then I move on to Alignmaster [http://www.alignmaster.de/] which is really helpful as it shows me what stars I can actually see with many blocked horizons.

The issue I am having is when making the 'small' adjustments with bolts to get the target star bang in the centre. First of all the (upgraded) Alt bolts are really really hard to move - especially the stiff 'handled' bolt underneath the polar scope. When I do manage to move it the stars seem to move in totally obscure directions - it's not left right up down, for example. I find it nearly impossible to move the star where I want it.

At the moment I am doing it through short exposures in BYEOS but am just purchasing a new 10x60 image corrected right angle finder which should make this easier.

Does anyone have any tips with this?

[daz]

The alt and az adjustment on the EQ6 is one of it's weakest points IMHO. I had similar issues!

I ended up stripping the mount and replacing the plastic disc washer with a piece of teflon-like material - and using the same material between the head and tripod.

I also drilled through the side altitude marker plate to access the three set screws that control the altitude tension.

You might also want to remove the new bolts completely and add a few drops of lubricant - lithium grease for example.

It does practise to get the tensions just right to move the mount in small increments!

[mrflib]

Sounds like a good plan... if I didn't have ten thumbs! Is there a guide on how to do this type of thing? I think I'll need to go down this route. I'll get some grease this weekend.

Other than that I take it maneuvering stars in to view is just a matter of practice? I wonder if there's a simulator anywhere to practice on. Off to Google.

[Gomtuu]

Please don't bite my head off if I'm misreading this query, but when you say "The issue I am having is when making the 'small' adjustments with bolts to get the target star bang in the centre", do you mean Polaris, or are you trying to align other stars?

As far as I know, the alt/az bolts are purely for aligning the mount by positioning Polaris in the polarscope.

[mrflib]

Sorry Mark - to be more specfic I am following the guide for the well-reviewed Alignmaster (http://www.alignmaster.de/Alignmaster.aspx). I have already polar aligned by this stage through EQ Mod at a level very sufficient for observing but not for imaging.

So I'm having these issues when looking at stars such as Vega, Dubhe etc.

However, I feel I might have found a major problem in my set up which is likely contributing significantly to my difficulty. Alignmaster requires the mount to be level so that when it asks you to make adjustments to the bolts you are only required to do either Alt or Az at any given time. The problem I am having is that stars are moving off in both alt and az - which should not be the case. I think this may be due to me not taking enough time to level the mount. Currently I just eyeball the bubble to be roughly centre, I think I will need to start removing the top and levelling the tripod exactly with a spirit level!

I am sorry if this doesn't make sense, I am not a word-master and it's one of those things which is difficult to explain but you would understand within seconds if you saw it.

[dmahon]

Are you guiding?

EQMOD's polar alignment routine has been enough for 30 minute subs for me (with my very unlevel mount) when guiding at 500 and 900mm focal length.

[Gomtuu]

Sorry Mark - to be more specfic I am following the guide for the well-reviewed Alignmaster (http://www.alignmast...lignmaster.aspx). I have already polar aligned by this stage through EQ Mod at a level very sufficient for observing but not for imaging.

That makes perfect sense. I understand what you're doing now.

As far as levelling the mount goes, I found that on my EQ5, the built-in spirit level was not correctly aligned. I ended up levelling it with my own spirit level, then marking the correct bubble position on the built-in with a felt pen.

My NEQ6's spirit level is properly aligned.

[mrflib]

Are you guiding?

EQMOD's polar alignment routine has been enough for 30 minute subs for me (with my very unlevel mount) when guiding at 500 and 900mm focal length.

I have a guider, yes, but I've not used it yet. I figured I'd try some unguided subs first to try and get used to imaging. It's so much harder than looking through the eyepiece! Would you recommend I stop being a ninny and plug it in? How much compensation does a guider offer?

[Daddystu]

I too find the EQMod polar alignment routine more than sufficient for a nights worth of 100% usable 15 min subs when guiding. I'm sure I could push the exposure time up too but my noisy cam wouldn't cope too well.