Atik - frame and focus

[mgirdwood]

hi Al

first connection of the Atik 314 to the scope tonight having decided to move up from my DSLR.  now I am know I must be doing something very basically wrong as I can not seem to get any kind of image for focus using the Artemis Capture software

Stood outside at the moment and all I am seeing is the attached. I have tried the full range of focuser movement.  the atik is connected to TS standard filter wheel,  15m extension ( ithink )and a Skywatcher flattener in front of it all

Anyone point me at the "bleeding obvious " please

Thanks

Mark

[ChrisLX200]

Yoy may need a longer extention?

ChrisH

[mgirdwood]

i did check with other threads on the subject and the spacers are about correct give or take a mm or 2.  but even at full focuser there is no change to the image.  i guess i could dump the flattener to test

[lensman57]

i did check with other threads on the subject and the spacers are about correct give or take a mm or 2.  but even at full focuser there is no change to the image.  i guess i could dump the flattener to test

Hi,

314l+ is very sensitive, this is how I do mine, I use a 1.25" diagonal with a 12.5mm plossl EP to center and focus on a bright star such as Vega, I then switch to CCD and FF/FR combination and have to move the focuser in a small amount inwards, as the stars appear the amount of movement to snap it into focus is very very small, I use a 1s loop as full frame in preview mode for focusing and then fine tune the focus using FWHM on a mag 3~4 star with 2s loops,  just be patient for the first few tries and you will do it blind folded afterwards.

A.G

[Davey-T]

Click on the drop down menu, view, and on the zoom slider move it until you get a green outlined frame, the zoom is a bit weird and if you can't see the outline of the picture you could be looking at a very small part, ignore the zoom 1 to 1.

Do you actually get an image that's finishing downloading, at the bottom of your pic it says "downloading" does this complete ?

Set it looping at 1sec exposure using Luminance filter on a bright target, Vega, or something like it, run the focus in and out to see any evidence of it.

Make sure that your finder is well aligned with your main scope, which is what by the way, you don't say which scope you're using.

Dave

[mgirdwood]

Thanks evryone

in desperation i placed the Atik directly onto a diagonal and lo and behold i was able to find focus.  _

AG, maybe this is similar to your description ? i will try with an eyepiece instead and then see what happens if i with in the FR>Wheel>Atik instead of the diagonal.

thanks Dave for that pointer as i was wondering how to get the smaller fov, 

with regards focus, i assume i can use a bartinov mask as i was with the Canon ?

Cheers

mark

[lensman57]

Thanks evryone

in desperation i placed the Atik directly onto a diagonal and lo and behold i was able to find focus.  _

AG, maybe this is similar to your description ? i will try with an eyepiece instead and then see what happens if i with in the FR>Wheel>Atik instead of the diagonal.

thanks Dave for that pointer as i was wondering how to get the smaller fov, 

with regards focus, i assume i can use a bartinov mask as i was with the Canon ?

Cheers

mark

By what you have described, you may have to add an extension tube to compensate for the lack of diagonal.

A.G

[mgirdwood]

Again thanks for the comments, luckily the weather held and i had a second clear night in a row, i was able to add the filter wheel etc in and get towards Focus, i am used to using a Bart mask with the Canon to focus which worked very well, however trying the same with the 314 the amount of starlight is very much less and its hard to determine if it is in good focus.

Does anyone have a good method i should try to focus ? especially i would think with the colour filters

many thanks Again

Mark

[ollypenrice]

You can use a Bahtinov and depending on your filters and your scope you may be effectively parfocal. WIth Baader filters and Takahashi optics this is the case for me. However, a less well corrected scope may not be truly parfocal across filters.

I do think FWHM in Artemis is slightly more accurate than a B mask but you need good seeing for this to be the case. When using FWHM use bin 1 and subs of 3 to 4 seconds. 1 sec is too short to average out the seeing. Draw a subframe round a star and double click on it to bring up the FWHM window. Make sure your brightness doesn't reach 65000 counts.

The fact that you could focus with a diagonal confirms that you need more extension, as AG says.

Olly