Is this best I am going to get with my setup

[YorkieGraham]

I have been trying my hand last year and this on Jupiter and now mars is up having a go at that. I wont embarrass myself with the mars shots but I was quite pleased with my Jupiter shots on the 28 Jan this year. I would like to know if this is the best I am going to get with my equipment or should I be getting better than this. I have managed to capture some detailing in the belts and even Ganymede and Io have joined in. My equipment is Celestron CR-6 (150mm) achromat on a motorised CG5 and philips webcam with a Baader semi apo filter processed in registax. 300 frames stacked. I still have the video if anyone wants to try getting more out of them and give me some pointers to improve my processing. I'm afraid a haven't been very good at recording what settings I used on each of my runs. Sorry.

Jupiter 28_01_2012 19_29_02.bmp

Jupiter 28_01_2012 19_29_02L.bmp

[Space Cowboy]

Thats a very nice image of Jupiter. Ideally you need to stack a few more frames (at least 500) to reduce the noise level and the colour balance is a bit out. I would say thats pretty much the best you can hope for given that Jupiter in Jan was well past its best.

An 8 or 10" scope would allow you to use more focal length giving the extra detail. Certainly for a faint object like Saturn a 10" scope makes a huge difference.

Btw if you download the free program "image analyser" it has a very good noise reduction function that would improve your Jupiter image.

[Pete Presland]

that's a pretty good image,as space cowboy says the more frames you have to stack the better off you will be.you should be able to get at least 1500 frames in each image run.

[YorkieGraham]

Thanks for the tips on stacking, I have been keeping it to 300 on all my imaging because that is what the tutorial said when I bought the philips webcam online. I seem to now be getting a different message from you guys, so I tried stacking 500 this morning, and I have to say it did look better. I also am getting a bit confused about how many frame per second to shoot. The tutorial said to aim for 10fps for good seeing and 5fps when it is very good. I never seem to be able to achieve this and the video capture usually drops loads of frames at this level. I usually end up at 15 - 25fps. Is this OK or am I doing something wrong.

[Asimov]

They are fairly good images. I started photographing planets with the same setup as you & unfortunately, an Achro. refractor will never give you correct colour results, even with filters.

As for stacking amounts; this is directionally proportional to the seeing conditions. Perfect seeing would allow you to stack every frame.

Yes that's correct. 5 FPS for very good seeing, 10 FPS for average. It's all about compression & anything above 10FPS you'll usually receive too much. As to why the dropped frames at these rates, no idea but no doubt it'll be computer/USB related.

[YorkieGraham]

Thanks for this. I will try my hand again with Mars and keep the frame rate down. I will also have another go at processing the Jupiter image and see if I can improve it some more, I didnt have long this morning as I was getting ready for work. Ill let you now how I get on. Thanks again everyone.

[Cath]

Judging by what results I seem to get, that's OK Graham.

Here's a stack of a 2 minute AVI (about 20fps) I did last night using my Celestron Nexstar 6 SE. It's a pretty small Jupiter

[YorkieGraham]

Cath - If you use a barlow lens you can increase the size of the image. My scope is F8 and I used a x3 barlow to get the image posted here. Your scope I think is an F10 so you would be getting similar results with an image a little larger than mine. I have just acquired a x4 barlow which I tried on Mars last night for the first time, with poor results, so it might be stretching my setup. But I will try again with my newly acquired knowledge from this post.

[Cath]

I have tried a 2* TAL barlow I got from FLO, and yes it does make Jupiter bigger, but it also removes any band detail due to fuzzing up the image

The other problem is the Nexstars tracking is pretty bad really, it's very jumpy and so has made any possible thoughts of doing long exposure photography impossible. The back lash in the motor gear boxs is a tad terrible - we stripped them down to have a look, plastic gears and VERY loose gear meshing is not good.

If we had the money we'd buy a small lathe and a small cnc miller to make some new gear box casings to get the gears to mesh properly - this would eliminate the back lash problem.

[Asimov]

Hi Cath. I've stripped plenty of mounts in my time so I think the drive jumping is probably fixable by careful cleaning - inspection - deburring - regreasing - careful adjustment of the RA/DEC worm & mainly the ring gears. Shame about the gearbox backlash but you'd be surprised how much can be taken out threw the worm to ring gear clearance..

[Cath]

Hi Asimov

Their aren't any worm gears on the Celestron mount. Their is no backlash on the main large gear, it's all in the little gearbox because the gears don't mesh together very well.

The jumping seems to be due to the backlash letting the scope move about.

This is what we found ..

[Asimov]

Sorry Cath, I was somehow assuming you had an EQ mount & didn't look at your sig. The 6SE is the one armed ALT/AZ mount scope?

[Cath]

Sorry Cath, I was somehow assuming you had an EQ mount & didn't look at your sig. The 6SE is the one armed ALT/AZ mount scope?

ooo don't worry

Yes it has one arm, but it's quite solid apart from the backlash.

You can get a new set of gears for the meade gearboxs that fix the same problem with them, but we haven't found anyone selling a replacement set of gears for the Nexstar mount, which is a shame.