Jump to content

sgl_imaging_challenge_2021_annual.thumb.jpg.3fc34f695a81b16210333189a3162ac7.jpg

Jupiter Sept 29th Skymax 127@ f47.2 (4x Barlow)


Space Cowboy
 Share

Recommended Posts

Not at all bad but I think f/47.2 may be too much ... the optimum focal ratio for most modern cameras (to capture all the detail the objective can resolve) is around f/25 - f/30 if you go beyond that the image is fainter, needing a longer exposure so more noise & more seeing blurring.

I find getting a good focus at around f/20 is hard enough!

Link to comment
Share on other sites

Cheers guys, yes I totally agree f47.2 is complete madness but wouldn't life be boring if we all stuck to the rules :icon_salut:

Seriously though I did take some shots at f30 which are ok but they were at a lower alt. I need to get a proper 3x Tal Barlow instead of improvising with 2 2x skywatcher barlows.

Link to comment
Share on other sites

These are great. You're getting more detail than my shots.

I have to ask.. how do you keep that image on the sensor at 4x! At just 2x I was struggling. What mount do you use? With my supatrak mount just touching the directions was shooting Jupiter off the sensor.

Link to comment
Share on other sites

Thanks mate! I have the GOTO mount so have the advantage of using star alignment to increase the tracking accuracy although at 4x I still have to make constant adjustments with the hand control. I'm not sure how your auto track controls compare though I do believe the tripod is not quite as sturdy as the GOTO version.

If you are having trouble with Jupiter drifting you can try the avi cropping program "Castrator" which will fix the Planet in one place improving stacking and alignment in Registax.

Link to comment
Share on other sites

lookin good Stuart

its great achievement keeping Jupiter on Chip as this focal length and ratio,

aswell as gud practise and bit of fun, processing them is bit of challenge aswell i found

tapping jabbing buttons at this high power is much more difficult, how do you find it urself ?

i remember really struggling with just x2barlow at 1st

@Brian for some reason i find focussing at larger scale easier tho, not as detailed but i think better overall, and registax seems to prefer larger scale 2,

think somewhere between f/25-f40 would be max depending on seeing for Jupiter with this scope.

Edited by AztecastroMcJ
Link to comment
Share on other sites

Cheers Pete! I find Craterlet produces a richer more natural colour than astrocapture.

Thanks James! Keeping Jup on screen for 3 mins @ f47.6 certainly takes concentration especially when I'm using AA batteries to power the mount! Did have it plugged into the mains for this one so it was easier. Backlash can be a problem especially moving from left to right..right to left responds better lol Just a matter of practice.

Link to comment
Share on other sites

Those are fantastic pictures. I've only had mine for 4-5 weeks and have had a few attempts using a neximage. The tracking is not a major problem but focusing is. The slightest touch and the image starts jumping all over the screen, normally takes 5 seconds or more to settle down, then you touch the focuser and it starts all over again, plus I cant seem to get a really sharp image on the computer screen. Whats your secret?

Link to comment
Share on other sites

, plus I cant seem to get a really sharp image on the computer screen. Whats your secret?

'Wavelets' in Registax is the secret. The final processed image looks *A LOT* sharper than the video that's being recorded. In fact you can sharpen so much that even an out of focus video will appear sharp after being processed, however that's a misnomer as you will be losing detail that you would have seen if you focussed correctly.

If possible it's best to zoom in and focus on one of the galliean moons and then go back to Jupiter. (NB you will need different gain/exposure settings to view the moons than you will to expose Jupiter correctly).

Link to comment
Share on other sites

Those are fantastic pictures. I've only had mine for 4-5 weeks and have had a few attempts using a neximage. The tracking is not a major problem but focusing is. The slightest touch and the image starts jumping all over the screen, normally takes 5 seconds or more to settle down, then you touch the focuser and it starts all over again, plus I cant seem to get a really sharp image on the computer screen. Whats your secret?

Cheers mate!

If you are having trouble with vibration (assuming you have supatrak or GOTO setup) tighten all the screws etc on the tripod hinges. Hang something heavy from the accessory tray under the mount (some people even fill the tripod legs with sand). Only extending the legs halfway also helps with stability. I always stand the tripod on a lawn too.

As has been said you will never get a very sharp image on the video screen especially if the seeing is not good. I would definitely second using Jupiters moons for focusing.

Link to comment
Share on other sites

Will try hanging a weight (possibly a sandbag) under the tray and next time will focus on a moon first, getting the sharpest point of light that I can.

I'm also having made an aluminium knob to fit on the focuser, which should hopefully enable me to "fine tune" the focus more accuratly.

I was going to try tonight but the air is just too turbulant and damp where I live.

As soon as I've got a few photos I will post them on here.

Thanks for advice.

Steve.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.