Janky Jupiter

[powerlord]

Well.. tried my C8 last night.. and definately something wrong with it - i swear it seems it is collimated, but can't get stars to look like anything other than circular blob. bahtinov doesn't even show spikes.

Anyway, since one star is so blurry it's the size jupiter would be, I gave up with it.

so I swapped to my wee mak 102, and this is what I got. Is that about what I can expect ? It was with mak102 + 2.2 barlow.

pretty disappointed in that tbh, and dunno what to do with C8.. don't suppose anyone knows anyone in Suffolk/North Essex area that could look at it ?

stu

Edited July 29, 2021 by powerlord

[teoria_del_big_bang]

Not really done any planetary imaging so can't really comment.
Is this a single shot or stacked or what though ?

If it was only a single frame then I do not think it is too bad.

Steve

 

[powerlord]

10,000 frames. asi224 and mak 102 with 2.2x barlow.

tried pipp then autostakker, then wavelets on registax, and cuttinng out pipp.

thats all i could get out it.

when @paul mc c gets this:

out of a  mak127 and same camera I feel Im screwing up somehow

 

[rl]

Have you had previous success with the same setup? What does a star at the zenith look like?

The seeing was so bad on Jupiter after the rain yesterday I just gave up..

[powerlord]

ah well maybe that was it.

it's first time I tried a planet. I have used the mak102 before on stars and got decent results.

Perhaps I did just choose a day that the seeing was rubbish ?

[paul mc c]

2 hours ago, powerlord said:

ah well maybe that was it.

it's first time I tried a planet. I have used the mak102 before on stars and got decent results.

Perhaps I did just choose a day that the seeing was rubbish ?

Seeing plays a big part,in your c8 image it looks like the collimation is out going by the moons,look fan shaped.Try and connect the camera and focus on a bright star,and de focus looking at the computer screen,this is a good way to check your colimation.

[powerlord]

i don't think the mak 102 allows any collimation ?

that wasn't my C8 - it was the mak 102. C8 I didn't even try as after 40 mins of collimation it was still rubbish.

i've read that back focus on C8 should be 5" though, and I had it much closer - around 2". but it was focusing... but maybe not optimally ?

so just tried to collimate it again pointing at a ball bearing on a bit of black flow at the end of the garden. I dunno.. seems better.. but I thought that last time until pointing at a star and finding it rubbish

Edited July 29, 2021 by powerlord

[paul mc c]

45 minutes ago, powerlord said:

i don't think the mak 102 allows any collimation ?

 

Is there no screws at the back of the ota.

[Peter_D]

On a night of good seeing, use Polaris to check and collimate your C8. SCT collimation needs to be spot on (pardon the pun) to get sharp images when seeing permits.

[The Lazy Astronomer]

Good planetary imaging is sooo dependant on seeing conditions. Don't beat yourself up too much, it's likely it was the conditions holding you back.

Is your SCT the standard version or the edge hd?

[vlaiv]

Loose x2.2 barlow on mak 102. It is F/13 and that is close to optimum F/15 for ASI224, you don't need to go high.

Focus as best as you can, but keep exposure length very short - about 5ms or so. Don't look at histogram, it is no use for planetary. Use very high gain - 350.

 

[powerlord]

Hi Vlaiv, I shot video with and without the x2.2, the x2.2 was the better of them. Still poor, but more detail than without. I think I shot with 135 gain though, so that's something to try next time, thanks.

though frankly I'd rather not be using the wee Mak if I can get the C8 working properly.

stu