collimation ?

[Pete Presland]

dont laugh this a very long winded way of showing what i see when i look through my cheshire collimator.

is it correctly collimated or does the inner disc need to be central the middle of the black disc?

i would have simply scanned the original drawing but the printer would not play ball ,things started to get a bit annoying from there anyway 45 mins later i managed this!

i have not done the star test yet as clear skies seem to be a thing of the past at the moment !

[johnkirkpatrick]

My scope when I collimate looks just like that, I think it should be central but some scope require an offset ( but if unsure assume its to be central), but telling the truth Im pretty new to collimating too. hopefully someone will confirm if am right or wrong.

I have just started to use the barlowed method and so far so good.

[yeti monster]

I found a brilliant and well presented collimation guide for my SNT on Cloudy Nights, perhaps if you search (I think I just googled for mine) "collimation [scope]" you may come up trumping. If you do find one, print it off and put it in a binder for future/field reference.

[TopHouse]

the black will appear offset but the inner circle, (your secondary) should appear central within the primary, on the above drawing it doesn't look it.

Check this out :-

http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm

[Jason D]

is it correctly collimated or does the inner disc need to be central the middle of the black disc?

Refer to post#21 in the following link

http://stargazerslounge.com/beginners-help-advice/99007-collimation-grateful-some-advice.html

I included a technical reason explaining why the dark and inner disc areas typically look non-concentric.

Also refer to post#47 in the following link

http://stargazerslounge.com/beginners-help-advice/99007-collimation-grateful-some-advice-2.html

which shows how it is possible to make the dark and inner disc areas concentric but collimation in this case will not be optimal

Bottom line, do not pay attention to the non-concentricity of the dark versus inner disc areas. The only catch is to ensure the dark area shift is in the primary mirror direction.

Jason

[Pete Presland]

the black will appear offset but the inner circle, (your secondary) should appear central within the primary, on the above drawing it doesn't look it.

Check this out :-

Astro Babys Guide to Collimation

thanks!!! thats a great guide have printed off as suggested i think i am pretty much there,did the star test last night seems ok.

[Pete Presland]

My scope when I collimate looks just like that, I think it should be central but some scope require an offset ( but if unsure assume its to be central), but telling the truth Im pretty new to collimating too. hopefully someone will confirm if am right or wrong.

I have just started to use the barlowed method and so far so good.

i followed this guide thanks to top house and it said what we see is normal for fast f5 scopes,its well worth a look!

Astro Babys Guide to Collimation

[Astro_Baby]

I'll take a look myself

[Pete Presland]

I'll take a look myself

it is very clear and easy to use,you have done a very good job with it thanks :hello2: