Never in the face of human conflict has so much been asked by so few to so many.

[Mac]

Never in the face of human conflict has so much been asked by so few to so many.

I think that for people that are beginning to image, guide, process, ect ect, you need to lean the basics first.
Even the good imagers have bad days and bad imagers have good days.

1) Get your Image. Stuff guiding, who cares about field flatners, barlows, star trails, filters. No image means exactly that. NOTHING.
  Work on getting an image, If your Image has stars in it, good, you have completed step one. If they are trailing good, it means you still have an IMAGE.
  Once you have worked out that you need 300 seconds to get an image of the veil nebula fine, or 60 seconds for M13, whatever, You need an IMAGE.
  It needs to be focused, a blurred images is useless, work on getting the first steps correct an image that is in focus.
Remember they are not called faint fuzzies for nothing. The fainter the object the longer time you need to capture an image.

2) what next, Filters or barlows or guiding. good question. My personal feeling is Filters.
   When you add a filter you need to understand the following. Not all filters are par focal.
   (i.e. different filters will focus at different places) work these focus positions out (or get par focal filters), this comes down to the original 1) get your image.
   Narrow band images filter out more of the light allowing only a NARROW band of light through to the camera. These will now take longer to get the image.
  again back to 1) get your image, the original 60 seconds may now take 300 seconds with the filter.

3) Barlo & Field flatner. Simple Barlos make your telescope longer, Field flatners normally make them shorter and stops the edges of the images being curved. (beginners guide)
 
   If your telescope has a focal length of 1000mm and you put a 2x barlo on it is now a 2000mm telescope
   If your telescope has a focal length of 1000mm and you put a 4x barlo on it is now a 4000mm telescope
   So what does this mean.
  Basicaly it means the following.

 If your 1000mm scope's field of view is the following then with the following barlows the field of view becomes as such

      1000mm                                2000mm                                  4000mm
      XXXX                                    XX                                          X
      XXXX                                    XX                                      
      XXXX
      XXXX

so putting a 2x barlo on you get 1/4 of the original image and with a 4x its 1/16 and if you want to put a 5x on its 1/25
This also means that the amount of light is reduced by the same ratio!!

a 10 sec image becomes the following. 2x 40 secs   4x 160 secs & 5x 250 secs, learn your basics.
If you put filters on with a barlo, your time goes up again.

Field flatners work in the opposite way i.e., a minus barlo.
your image goes from                               to

      XXXX                                            XXXXXX
      XXXX                                            XXXXXX    
      XXXX                                            XXXXXX
      XXXX                                            XXXXXX
                                                         XXXXXX
                                                         XXXXXX

Like wise your times for images come down, so a 10 secs image will only take 6 secs.

4) Guiding. (to follow) depends on software.

[Carole]

Thanks Mac,

Didn't realise this:

This also means that the amount of light is reduced by the same ratio!!

Carole

[Ian]

moving to technical and stickying I think. Might append other useful posts as time goes by.

Thanks Mac.

[Mac]

Ian just to let you know.

Im re-writing this and will post it later for you to re-sticky it.
Its currently 8 pages and climbing.

Mac.

[Ian]

cool. you should be able to edit the first post here. When you do, I'll trim this chat off and then it'll be somewhere we can post useful stuff to...

[Rick]

Something to add to the main website, perhaps?

[Tony G]

Im re-writing this
Mac.

Speak to Mike, and see what you need to do to get it published.

Tony G

[Rocket Pooch]

You missed a bit on reducers, they make the light cone smaller by compressing the light so they are more prone to vignetting.

[Mac]

true but its just a basic start up though.

[Mac]

I've reposted this in a new message and split it into 5 replies as the original one was to larger for one message.

Ian can you make that one the sticky please.

I do have the file as word doc if you want to post it on the main page.
All have a read and let me know if i've messed something up.
Dont forget it is a beginners guide and not meant to be very detailed. just give people an insite
as to what should be happening.

http://forum.orpington-astronomy.org.uk/index.php?topic=6334.0

cheers Mac.