More Jupiter - how do I improve this?

[Penguin]

Sorry to ask yet another beginners question on Jupiter! Here is a still from my latest attempt:

This was taken using WXAstrostack through a philips SPC900 through a 3x Barlow on a TAL-1 4.5" newtonian reflactor (f7.3)

I have taken several AVIs and they all look pretty much like this: you can see the bands but no detail. I have seen other peoples shots with detail in the cloud belts, acheived with 5" scopes, eg this one: http://blog.swanastro.org.uk/2011/11/capturing-jupiter-with-linux-and.html . I am taking 3-minute AVIs at 10 fps. Sometimes it is slightly brighter and sometimes a little dimmer, depending on the WXAstroCapture gain/gamma/brightness settings I choose but whatever I do, I can't tease any details out. I bought a cheap 2x Barlow in case the magnification was too much for the scope but I can't even get a focus with that.

Do I really just need a bigger scope?

Collimation? it seemed ok on un-focused stars: nice and regular shape)

Focussing? I used a bhatinov mask to get as good as I could

Too much magnification? I have a 2x Barlow but can't get focus through it so I am stuck with the 3x.

WXAstrCapture settings? I can't remember what I had except that I always try to keep the gain at 0.

Is there any point in putting a video like this through Registax?

--- Alistair.

[Keener_7]

That looks pretty good for a single frame from a webcam. Yes definitely put the vids through registax. It will clean up the image and bring out the detail.

[JamesF]

It's a fair while since I've used anything other than SharpCap for capture because I found it more flexible, but hopefully these settings will be useful. I'd say you want gamma at minimum and gain at around 50%, perhaps a bit more with your scope. In SharpCap I pop up the histogram display and fiddle with the gain until the histogram reaches about 70% of the width of the graph. Brightness I leave at 50%. Exposure I'd go for as long as possible.

I think you should be ok with a 3x barlow, but you will find that even the thinnest of cloud can completely ruin the image and the camera may pick up almost nothing even when you can still see Jupiter with the naked eye.

James

[boabsta]

Am I the only idiot who clicked on the red X to exit the picture

[astromerlin]

Hi, I use WXastrocapture quite frequently for planetary imaging.

Set the brightness at 50%, set the gamma at zero, gain at about 65% and the shutter at about 33

When i'm imaging I try to keep the gain between 60 to 80%, and adjust the shutter and gain for maximum brightness without over cooking it.

[nephilim]

Am I the only idiot who clicked on the red X to exit the picture

haha nope, I did too.

[bomberbaz]

Neat looking image if you ask me

[Penguin]

Am I the only idiot who clicked on the red X to exit the picture

Nope, I did as well, after reading your and Nephilim's posts! And I am the one who started the thread!

I think maybe need some more practice in Registax then, I can't get it to give me anything better than the original stills at the moment. I would post the AVI but it's half a gig.

--- Alistair.

[atmenterprises]

Here are the settings I used and the resulting picture from those settings. Might give you an idea of some things to tweak.

But I had the gamma up too high and I think that may have contributed to the grain in the picture. But this should give you an idea on about where your settings should be.

[Bad_Dan]

Wow atmenterprises! That picture is great! What sort of shutter speed was that using though? For jupiter i always try around 1/50 or 1/100. If i have the gain on anything like 1/33 or 1/50 it just complete burns out the picture.

[Bad_Dan]

Wow atmenterprises! That picture is great! What sort of shutter speed was that using though? For jupiter i always try around 1/50 or 1/100. If i have the gain on anything like 1/33 or 1/50 it just complete burns out the picture.

Sorry to double post. I ment to say if i use any sort of gain whilst under shutter speeds; 1/33 and 1/50 it burns the picture out.

[atmenterprises]

Sorry to double post. I ment to say if i use any sort of gain whilst under shutter speeds; 1/33 and 1/50 it burns the picture out.

It was 10 fps. Help me on my math. Are there 100 milliseconds in one second or 1000? So it's either 1/10 or 1/100 depending on that answer.

[PH-R]

I have just started using Sharpcam as well my settings can be found on my recent post here: http://stargazerslounge.com/topic/170626-jupiter-10-12-2012-100ed-progression-my-first-animation/ also your avi looks similar to what I receive. Well done!

Can anyone tell me the what -7 exposure is? compared to 1/25 etc...

Best wishes,

[atmenterprises]

I have just started using Sharpcam as well my settings can be found on my recent post here: http://stargazerslounge.com/topic/170626-jupiter-10-12-2012-100ed-progression-my-first-animation/ also your avi looks similar to what I receive. Well done!

Can anyone tell me the what -7 exposure is? compared to 1/25 etc...

Best wishes,

I always assumed (and this is a big assumption!) that it was exposure compensation. The lower the number (meaning -6 is lower than -2), the darker your image because it affects the exposure. Exactly how it does the manipulation is beyond me. It's like the EV setting on a dSLR.

Again, all speculation on my part.

[JamesF]

I always assumed (and this is a big assumption!) that it was exposure compensation. The lower the number (meaning -6 is lower than -2), the darker your image because it affects the exposure. Exactly how it does the manipulation is beyond me. It's like the EV setting on a dSLR.

Again, all speculation on my part.

The way I understand this to work is that the driver (which may be for a number of different cameras) asks the camera what functions it supports and what ranges of values are applicable (for those functions with parameter ranges). The application can then get that data from the driver.

So, for exposure time the camera presumably reports the valid range of values is (say) 0 to -7. What that actually means in terms of shutter speed is anyone's guess. Perhaps reading the camera firmware might provide enlightenment, but otherwise unless the camera manufacturer tells you there's probably no way to be sure.

The Xbox camera reports (from memory) a valid range of 0x0000 to 0xffff for exposure time. I think the windows driver must rescale that somehow. My recollection is that the number is defined to be the number of milliseconds for exposure for that camera type, though I found I couldn't get the Xbox camera to an exposure time of more than about 3.5 seconds.

James

[Aenima]

Hi,

Maybe some of what I've picked up over the past few months will be of some use. (apologies if not.)

A plus 1 for registax, though try initial stacking in Autostakkert!2 then use registax wavelets to gently sharpen the output stack image file, first use registax 'Align RGB' estimate button - it fixes atmospheric interference. Sometimes with sharpening with wavelets I realised a subtle approach ends up better, less seems to be more in this respect. (a tutorial suggested using sliders 2 & 3 - and I found about halfway works well with a few clicks on 'sharpen' button.

I have found that with my 8" I still need a x2 and a x1.5 barlow to boost the size, as a barlowed but less bright larger image seems to work better than using the software to zoom a smaller but brighter image up to scale.

In sharpcap, I usually find a balance involving lowest gain (gain brings noise) with highest exposure before going into the red - slide up to the point before overexposing, then use the other controls - brightness, (not sure about wxastrocapture, sorry) etc - to get the onscreen image looking solid and as sharp as you can without losing details due to overexposure, (better to brighten later than to try recovering too-bright images, you can always increase gain afterwards with settings but cant bring back the lost data if overexposed) and aim to keep the planet centered and steady whilst working out focus (a bahtinov mask on a bright star helps but you'll need to up the gain to see the spikes then redo settings once focused) ..

Stacking really helps clean the image up. Registax is a bit strange at first but alot of the complex settings can be left at default as you familiarise with the software, autostakkert2 is the easiest to use and works well to produce an unsharpened image that goes into registax as a PNG file for wavelets.

Sorry to ramble, its difficult to work out what things will be of help and not just repeat what you already know O.o

Hope any of it helps.

Best of luck with Jupiter this month, its quite big at the moment.

Regards

Aenima