Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

stargazine_ep2_banner.thumb.jpg.e37c929f88100393e885b7befec4c749.jpg

Fordos Moon

First Image of Jupiter with ASI120MM - advice please

Recommended Posts

post-26268-0-84576700-1395648716.jpg

Morning All,

Last night I managed this image of Jupiter and I would appreciate your tips on how to improve it.

Equipment was 200P on HEQ5 with ASI120MM and Televue 2.5 powermate.

Captured in Firecapture beta. 60 seconds. 512x440. Gain 41. Exposure time 13.65. 72 fps. Gamma 26.

Processed in Virtual Dub, Castrator, AS2 and Registax 6.

Whilst content with the image for my first with the new camera, I know better will come.

My initial thoughts are:

1. Should I have taken a 2 minute AVI or is 4,300 frames enough?

2. Is the main problem I am out of focus and should work more on this next time?

3. I notice a slight onion ring. Have I overdone the sliders?

Your advice as always would be most appreciated.

Edited by Fordos Moon

Share this post


Link to post
Share on other sites

Not bad for a first effort with a new camera. I think there is a bit of onion-ringing going on, which can be a case of exposure or gain set too low. I use the histogram tool in firecapture to ensure about 80-80% of the ADC range is used. This helps a lot. Focus is always a hassle, and I use the moons quite a lot to judge focus. My best shots with the ASI120MC to date have been at F/20, so maybe you can go beyond the F/15 which you are using.

Share this post


Link to post
Share on other sites

Not bad for a first effort with a new camera. I think there is a bit of onion-ringing going on, which can be a case of exposure or gain set too low. I use the histogram tool in firecapture to ensure about 80-80% of the ADC range is used. This helps a lot. Focus is always a hassle, and I use the moons quite a lot to judge focus. My best shots with the ASI120MC to date have been at F/20, so maybe you can go beyond the F/15 which you are using.

Michael many thanks for this, and I will take "not bad for a first effort" quite happily. I will make a note to check out the firecapture histogram - thanks again!

Share this post


Link to post
Share on other sites

Michael many thanks for this, and I will take "not bad for a first effort" quite happily. I will make a note to check out the firecapture histogram - thanks again!

My first capture with the ASI120MC was a good deal worse.

  • Like 1

Share this post


Link to post
Share on other sites

Looks ok looks soft to me focus seems a tad of but all round looks like a first attempt I would not worry.mine was nothing like this just a ball with a couple a bands on it, I do not have this camera so not sure if the settings are right or wrong but a good first image

Pat

  • Like 1

Share this post


Link to post
Share on other sites

I agree.

The histogram is very useful for balancing gain and exposure.  I tend to select the exposure to get the frame rate I'm after, then adjust the gain to get a suitable histogram.  If that means the gain is much getting over 60% then I may well think about increasing the exposure time.  It is all a bit "touchy feely" though.

Focus is, well, practice and more practice really.  Motorised focusers help enormously because there's no wobble when the focuser is moving.  It made a huge difference when I made one for the 127 Mak and I'm in the process of making one for my PST before doing one for the C9.25.  I seem to have done well with motor focusers.  Despite the two mounting brackets they're supplied with I've had to make a bespoke bracket for all of mine :)

James

  • Like 1

Share this post


Link to post
Share on other sites

I agree.

The histogram is very useful for balancing gain and exposure.  I tend to select the exposure to get the frame rate I'm after, then adjust the gain to get a suitable histogram.  If that means the gain is much getting over 60% then I may well think about increasing the exposure time.  It is all a bit "touchy feely" though.

Focus is, well, practice and more practice really.  Motorised focusers help enormously because there's no wobble when the focuser is moving.  It made a huge difference when I made one for the 127 Mak and I'm in the process of making one for my PST before doing one for the C9.25.  I seem to have done well with motor focusers.  Despite the two mounting brackets they're supplied with I've had to make a bespoke bracket for all of mine :)

James

James - thanks for popping in! Are the required frame rates and histogram shapes trial and error or has a good starting point been established? I must invest in a motorised focusser one day.

Share this post


Link to post
Share on other sites

James - thanks for popping in! Are the required frame rates and histogram shapes trial and error or has a good starting point been established? I must invest in a motorised focusser one day.

I'd say the histogram is important to get close to right whether it's 70% or 80% won't kill you, but if you don't have enough dynamic range in the image then you'll be struggling for data to process.  Frame rate is up to you really, but anything between 30fps and 60fps is probably reasonable.  Fast is good, but requires more gain and gain means noise, so again it's something of a balancing act.

James

  • Like 1

Share this post


Link to post
Share on other sites

I agree.

The histogram is very useful for balancing gain and exposure.  I tend to select the exposure to get the frame rate I'm after, then adjust the gain to get a suitable histogram.  If that means the gain is much getting over 60% then I may well think about increasing the exposure time.  It is all a bit "touchy feely" though.

Focus is, well, practice and more practice really.  Motorised focusers help enormously because there's no wobble when the focuser is moving.  It made a huge difference when I made one for the 127 Mak and I'm in the process of making one for my PST before doing one for the C9.25.  I seem to have done well with motor focusers.  Despite the two mounting brackets they're supplied with I've had to make a bespoke bracket for all of mine :)

James

i like to see the results of the motor for the 9.25 James, been thinking of trying to do something for my 8" sct without paying crazy money for a tailored motorised focuser,

as for you jupiter image, that certainly isn`t too bad, did you try the wavelets in registax to sharpen the detail any ?

my first effort with the mono asi 120 was about just as good as yours, i was trying the filters aswell to get a coloured image, you have to be quick, 30 seconds on each colour and i luminance with a manual filter wheel, very tricky L.O.L.

  • Like 1

Share this post


Link to post
Share on other sites

as for you jupiter image, that certainly isn`t too bad, did you try the wavelets in registax to sharpen the detail any ?

.

I did use the wavelets Red, but even with the top one at 100% it would not sharpen any more, which confused me somewhat and made me think I was out of focus.

Share this post


Link to post
Share on other sites

I did have a go at capturing Mars but it appeared very very wobbly (fairly low in sky i know), perhaps something beyond my ability and equipment? But will try again! 

Share this post


Link to post
Share on other sites

i like to see the results of the motor for the 9.25 James, been thinking of trying to do something for my 8" sct without paying crazy money for a tailored motorised focuser,

I do have an external focuser on the C9.25 which should make things a little easier when it comes to motorising than my 127 Mak where I drive the focuser knob directly.  It's only a Revelation dual-speed R&P model though.

My experience with the Mak was that the mirror slop when changing focuser direction was enough at long focal lengths to take the image entirely off the sensor, but I didn't want to fit an external focuser there because the extra backfocus would have made the effective focal length too long for the Moon and Sun discs to fit on my DSLR sensor (perhaps I should get a full-frame camera :D

I'm unlikely to use the C9.25 for full disc lunar and solar though, so the external focuser removes the mirror problem and hopefully makes for a simpler motorisation mod as well.  I've started with the PST first though as I have the crayford focuser on that and there are at least screws to fit a bracket with.  The R&P model has a dearth of potential mounting points, so I need to engineer an alternative for that.

James

Share this post


Link to post
Share on other sites

Played around with the wavelet sharpening option, although could do with a guide to be honest!

post-26268-0-56478700-1395701163.jpg

Share this post


Link to post
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

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By Cosmic Geoff
      I imaged Jupiter, Saturn and Mars this morning around 3.30am in the interval between 'high enough' and dawn.  Equipment: CPC800, ASI224MC, ADC. Captured with Sharpcap, processed with Registax6. Used best 20% of 5000 frame videos.
      It's so long since I did any planetary imaging that I had to re-learn what to do. The Jupiter and Saturn images seem under-exposed.



    • By merlin100
      The first two photos were taken using my BST StarGuider 3.2mm ED EP. The middle one was using a 25mm MA EP. The last two were taking with a 10mm MA EP. 
      I was just holding the phone to the eyepiece, using the zoom and exposure compensation. I have no control of the ISO with this phone, even using the Open Camera app. 





    • By Victor Boesen
      Yesterday I managed to climb out of bed at a little past 3:30AM to get my small portable rig out to a small nearby park and setup to observe Jupiter, Saturn and Mars. I got the Skywatcher Evostar 72ED DS-Pro last summer so I was especially excited to see how it would perform on Mars because of its red wavelengths which many small fracs often have trouble with handling.
      At first it was partly cloudy but I persisted and was out and setup on the field at around 4AM. The sky was already surprisingly bright here in Denmark but Jupiter was shining bright and Saturn faintly visible almost right besides Jupiter. Fortunately for me it wasn't too cold, but I was happy I brought some gloves anyways;)

      This picture was taken at 5AM while I was observing Mars.
      I remember from last year that my scope didn't perform great on Jupiter for some reason, and the view of the gas giant wasn't anything different this time either. Using my 4.7mm ES 82 degree eyepiece not much detail visible except the two main bands and its moons. I would later return to Jupiter after the scope had cooled down a little and the view was perhaps a little sharper.
      Pointing the scope at Saturn, which I was very satisfied with last year, I was amazed of the detail the small scope managed to squeeze out. It doesn't compare to the view I had last year with my 10" dob under great conditions at 255X but I was able to easily spot surface banding on the planet itself, and the Cassini division was also surprisingly stable. I really enjoy the stable and consistent view through the small refractor! I observed Saturn for quite a while until I eventually set out to try to find Mars. At this point I couldn't even see Saturn with the naked eye but I was fortunate that Saturn and Mars were approximately the same elevation above the horizon.
      After a few sweeps across where I though Mars would be I finally located the small red speckle, this time with my 6.7mm eyepiece so I had a larger FOV. Switching to the 4.7mm, though still very small, I was surprised that I could pick up a dark surface marking across the disk on the lower southern half of the disk. Furthermore, the southern polar cap was really pronounced and you couldn't miss it. I watched Mars drift through the FOV until about 30 minutes after sunrise where the contrast between the planet and the sky became too low and the dew started to set on the lens element.
      Using my small refractor for observing the planets I have always wanted to magnify things a little bit more, and I think the telescope would have no problem doing so. A Nagler zoom 3-6mm has been on my wish-list for a couple of years now, but the upcoming planet season really makes me want to find one second hand
      Here's a video I've made that covers what I've written above with some footage I tried capturing through the eyepiece:
      I hope everyone on here is still doing well despite the current situation!
      Clear skies!
      Victor
    • By spaceman_spiff
      This is a re-processed set of 159 images taken from a few years ago. Each image was generated from a 3 minute video. It shows Europa passing across the face of Jupiter casting it's shadow across the northern hemisphere. Telescope: Skymax 150 Maksutov with a TeleVue 2x Barlow lens and a Baader fringe killer filter. Camera: Canon 550D in 640x480 crop mode. ISO Auto at 1/60s exposure. Processing: Quality filtering and centring done using Pipp, stacking and wavelets processing done using Registax 6.
    • By mikeyscope
      This planetary grouping from 20th March around 5.30am shows Saturn to the left with conjunction of Jupiter above & Mars below, sharp eyed may also see...  Io, Ganymede & Callisto in a string just right of Jupiter.
      Image taken from Lesmahagow, South Lanarkshire looking toward the SE.
      Pentax K1 / Pentax 67  165mm lens / Exp. 2 secs @f8 / iso 200
      Ioptron tracker at siderial.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.