Tips for planetary imaging.

[WilliamAstro]

This post has been edited due to several errors of information, so I am happy to change this topic over to sharing tips of better planetary imaging instead.

Edited August 18, 2022 by WilliamAstro

[Dragon_Astro]

Any tips on getting a planet on a small camera chip? It drives me insane lol

[MarkRadice]

Can’t argue with that! Expanding your first point, I'd break it down into 

i) imaging near the meridian 

ii) keeping an eye on the jet stream 

iii) moving to the tropics where the planets are higher 

 

10 hours ago, Dragon_Astro said:

Any tips on getting a planet on a small camera chip? It drives me insane lol

I suggest a flip mirror like this one - few choices on the market. https://www.rothervalleyoptics.co.uk/rvo-125-flip-mirror-system-with-micro-focuser.html

[CraigT82]

10 hours ago, Dragon_Astro said:

Any tips on getting a planet on a small camera chip? It drives me insane lol

What kit are you using? This is a frustrating aspect of planetary imaging and I’ve certainly struggled with it.

[neil phillips]

Its not that hard. First centre the planet in a high power eyepiece. Carefully put camera in. Have tracking running.  Put the camera into full resolution. downsize the zoom to around 60% raise gain to 90% use around 1/60th secs exposure. gently move the scope around a touch. if its not there. Or you cant see a out of focus ring. Centre with high power eyepiece and try again. Doesn't take me longer than a couple of mins doing this. 

[Steve Ward]

Like he says ... with the additional point of when you have the target centred in the eyepiece make sure to tweak the finderscope to match ... that will make it a breeze to relocate the target when you accidentally clonk a tripod leg later when faffing about in the dark .... been there just the other night ... 🤣

[MarkRadice]

I don’t know how you guys do it so easily! I find it a breeze with a flip mirror but so frustrating without - that’s with a 224mc on C11 at f20. 
 

I also unscrewed my Barlow lens and screwed it onto the flip mirror negating the huge increase in magnification that would otherwise entail. 
 

One other thing I noticed, make sure the ADC arms are aligned. If they are set for altitude, the planet is now not aligned with the optical axis. I hope that makes sense! In summary, if you twiddle the ADC the planet wanders off! 

[neil phillips]

8 hours ago, MarkRadice said:

I don’t know how you guys do it so easily! I find it a breeze with a flip mirror but so frustrating without - that’s with a 224mc on C11 at f20. 
 

I also unscrewed my Barlow lens and screwed it onto the flip mirror negating the huge increase in magnification that would otherwise entail. 
 

One other thing I noticed, make sure the ADC arms are aligned. If they are set for altitude, the planet is now not aligned with the optical axis. I hope that makes sense! In summary, if you twiddle the ADC the planet wanders off! 

Haven't done the math, but I will bet your focal length is longer Mark. Even a slight increase might make these things more troublesome. I did have trouble years ago mind. But doing the procedure I just outlined. I usually only have to re centre in the eyepiece once, usually.

Often I will get it first attempt. By putting the resolution on max. your increasing the area for the planet. By zooming down it is not cut off. and you can see all of the area in one go.

By increasing gain and slowing exposure if your grossly out of focus the ring will still show up. is theory on this.

Edited August 14, 2022 by neil phillips

[knobby]

The Barlow isn't always a necessity... You want to aim for around 3 x the pixel size of your camera as an F number, maybe up to 5 times if seeing is good.

Edited August 14, 2022 by knobby
typo

[Dragon_Astro]

On 14/08/2022 at 07:29, CraigT82 said:

What kit are you using? This is a frustrating aspect of planetary imaging and I’ve certainly struggled with it.

A SW 127 Mak, with a 224 chip camera. Currently only have a x3 Barlow but have just bought a x2…

a vintage Celestron Ultima SV

[Jane C]

On 13/08/2022 at 21:01, Dragon_Astro said:

Any tips on getting a planet on a small camera chip? It drives me insane lol

I agree with MarkRadice.  I use a flip mirror.  As it happens, I use the one from Baader Planetarium. I keep a 40mm eyepiece in it by default.  But I also have a good quality, long eye relief 20mm eyepiece with cross-hairs.  

Finally, I control my equatorial mount with Celestron's own software, CPWI, from a PC.  I had to rebuild my database of stars in its "model" of the sky after a PC crash, but I now have about two dozen stars in it (and I have learnt how to back it up).  That's generally accurate enough that I don't need the finder scope unless I do something silly and knock the scope or hit the wrong slew button.  As the planets ply their orbits and move, I keep adding nearby stars to the "model".  Doing this works MUCH better than using the GOTO on the handset.

🙂

Jane.

[Jane C]

On 13/08/2022 at 00:29, WilliamAstro said:

 

4. Inaccurate Focus, Sometimes this occurs if the object is inaccurately in focus. I advise you NOT to use bahtinov masks as they are not reliable for focusing planets especially when it comes to high resolution planetary imaging. What you should do is focus on the planet, then tweak the focusing knob and carefully observe any details that appear or fade during focusing, once you get the most detail out of the focus then the focus is on point.

I can think of very little to say about focusing that is printable, but a lot that would get me banned from this forum in an instant for un-ladylike language 🤣.   I wonder what you think about focusing and collimating on a nearby star with Bahtinov and Tri-Bahtinov masks respectively, then slewing to the planet?

[CraigT82]

On 15/08/2022 at 09:07, Dragon_Astro said:

A SW 127 Mak, with a 224 chip camera. Currently only have a x3 Barlow but have just bought a x2…

a vintage Celestron Ultima SV

As your using a Mak the a flip mirror is the way to go. I’d also invest in a cross hair eyepiece to use in it, and also to use when zeroing your finder. 
 

I use a newt so a flip mirror is not an option due to lack of infocus travel. My technique is just to use a crosshair eyepiece to set up the finder in the daytime and usually that is fine to get the camera on the chip. If it fails for some reason then the spiral search function on EQmod comes in handy. 

Edited August 16, 2022 by CraigT82

[Jane C]

On the subject of focusing by looking at images on your screen, I would also add that varifocals make an annoying problem worse.  There is only a very small "sweet spot"  of sharp focus for any distance.  If you look at a slight angle, you can't see well enough to focus.

(I'm stuck with glasses because I have a ~3 dioptre cylindrical correction, but very little spherical correction, so a contact lens won't orient in my eye.  Apparently if I were also very short sighted, it would be possible to orient one, but I'm not.)

[WilliamAstro]

1 hour ago, Jane C said:

I can think of very little to say about focusing that is printable, but a lot that would get me banned from this forum in an instant for un-ladylike language 🤣.   I wonder what you think about focusing and collimating on a nearby star with Bahtinov and Tri-Bahtinov masks respectively, then slewing to the planet?

Focusing can be a pain in the backside..

Edited August 16, 2022 by WilliamAstro

[Elp]

Focusing isn't too bad if you have a zen like touch, almost to the point of imperceptibly tuning the focus to the point where it didn't seem to move at all. This however goes to pot if the sky conditions don't want to comply.

[johnturley]

On 14/08/2022 at 17:23, knobby said:

The Barlow isn't always a necessity... You want to aim for around 3 x the pixel size of your camera as an F number, maybe up to 5 times if seeing is good.

That will just result in tiny planetary images in the case of a lot of scopes, which you can't do much with in processing, for example with my ZWO ASI 462 the pixel size is just 2.9 um, which would equate to just F9.

John

Edited August 18, 2022 by johnturley

[knobby]

You're probably right, the 3 x pixel size is a pretty old rough guide.

[WilliamAstro]

24 minutes ago, Elp said:

Focusing isn't too bad if you have a zen like touch, almost to the point of imperceptibly tuning the focus to the point where it didn't seem to move at all. This however goes to pot if the sky conditions don't want to comply.

How I focus my telescope to planets is pointing to the planet and moving the focusing knob side to side and tweaking it and carefully observing the changes of detail on the planet. If the planet is revealing details like clouds belts on Jupiter, cassini division on saturn, then it's good to go. But when turbulence is rife it can be harder.

[Jane C]

2 hours ago, Elp said:

This however goes to pot if the sky conditions don't want to comply.

Amen! 🙃

[WilliamAstro]

On 13/08/2022 at 21:01, Dragon_Astro said:

Any tips on getting a planet on a small camera chip? It drives me insane lol

What I do is align the telescope to a star and make sure it's dead center using a high power eyepiece, then tweak the finderscope so it can co-ordinate with the OTA. Then I put my camera in and remember the location of where the object should go by the crosshairs then I easily find what I need to look for.

Edited August 18, 2022 by WilliamAstro