Televue np101is vs C11 Edge for Planets

[Rodd]

Hello all--I will finally get to hunt down Jupiter and Saturn tomorrow night in my first foray into planetary imaging.  I have been imaging DSOs with the np101is and C11 edge for a couple months now--I like them both for different things.  I am trying to decide what would be better for imaging Jupiter and Saturn--the Televue np101is with a 4x power mate (being about an f 21.4) or the C11 edge with a 2x powermate being about an f 20.  Not sure if seeing will support that--so with the C11 Edge I could use the native F-10.  My camera is the Celestron Skyris 618 color.  What do you think?

[Chris]

Hi, 

I would side with the massively increased resolution of the C11 over the 4" refractor for planetary imaging.

[Stu]

I should think the resolution available from the C11 by definition (being driven by aperture) would knock the socks off the 101, despite its many virtues. The benefit of imaging with many hundreds or thousands of short images is that by choosing the best ones you should be able to compensate for poor seeing, although the best results will still be on nights of good or excellent seeing. I assume your camera is capable of this?

The best planetary imagers in the world tend to use scopes like the C11 or C14, and plonk themselves at altitude somewhere with stable air conditions.

[Rodd]

4 minutes ago, Stu said:

I should think the resolution available from the C11 by definition (being driven by aperture) would knock the socks off the 101, despite its many virtues. The benefit of imaging with many hundreds or thousands of short images is that by choosing the best ones you should be able to compensate for poor seeing, although the best results will still be on nights of good or excellent seeing. I assume your camera is capable of this?

The best planetary imagers in the world tend to use scopes like the C11 or C14, and plonk themselves at altitude somewhere with stable air conditions.

Thanks for the help--yes the skyris (the same as imaging source 618 with a different brand name) is supposed to be able to do this.  I have only used it one time.  At that time I thought I took a 20sec video and would later turn it into subs for stacking in Registack--but I could never find the video.  I did take a snap shot of Copernicus crater that was cool--but only one and no processing.  I have been strictly deep space since I started imaging 2 months back.  I got the C11 for planetary work, but was not sure if a powermate could crank up the apo for planets.  The C11 it is.  I also have a 4 x powermate--but not sure what seeing needs to be in order to use it.  If I take a 1minute video at 30frames/sec,m would that be enough for a decent image?

[Stu]

2 minutes ago, Rodd said:

Thanks for the help--yes the skyris (the same as imaging source 618 with a different brand name) is supposed to be able to do this.  I have only used it one time.  At that time I thought I took a 20sec video and would later turn it into subs for stacking in Registack--but I could never find the video.  I did take a snap shot of Copernicus crater that was cool--but only one and no processing.  I have been strictly deep space since I started imaging 2 months back.  I got the C11 for planetary work, but was not sure if a powermate could crank up the apo for planets.  The C11 it is.  I also have a 4 x powermate--but not sure what seeing needs to be in order to use it.  If I take a 1minute video at 30frames/sec,m would that be enough for a decent image?

Best to wait for some input from one of the more experienced planetary imagers. I just do visual; I know enough to know the C11 will do the better job, but not the detail beyond that.

[Chris]

30 frames/sec should do the trick. I'm not the most experienced planetary imager by no means, but I've dabled with it in the past 

I went to a Damien Peach lecture recently, and the jist seemed to be the faster the better when it comes to frame rates. He uses a C14 Edge and ZWO cameras, that's the other thing I took from his lecture apart from lots a juicy images of Jupiter

 

[Kokatha man]

...not even the suggestion of a comparison between the 2 scopes - the C11 will be infinitely better!

[Pete Presland]

Use the C11 and make sure it has time to cool down. the C11 and skyris 618c sounds like a match made in heaven, looking forward to seeing the results!

[Barv]

As said before, no comparison between the 2 scopes.

Not wanting to hijack your thread but this is a picture taken with the C11 Edge HD, a televue 2.5X powermate bringing the f ratio up to 25, and a ZWO120MC camera. This was taken in the UK under excellent seeing and transparency. The date was 17/01/14.

Regards

Harvey

 

[Rodd]

10 hours ago, bunnygod1 said:

 

Wow Harvey--Awesome!!  I guess the C11 Edge with a 2x powermate and skyris 618c will do OK--not as big as yours--but close.   How long a video did you shoot?  I'm thinking 5 minutes at 30fps--I don't want to run out of disk space though--maybe 2 minutes is enough?  I have no clue.  Seeing is suppose to be average (rarely gets better here so its exciting even though its only average).  If seeing were better, I could use the 4X powermate and really have some fun.  I guess I could try it--not that big a deal switching from the 2x to the 4x.  Or I could use the .7x reducer and the 4X powermate and get 2.8x--not sure if all that glass will dim out the image.  

 

Thanks for the Pic.  It is amazingly clear.

[Barv]

48 minutes ago, Rodd said:

Wow Harvey--Awesome!!  I guess the C11 Edge with a 2x powermate and skyris 618c will do OK--not as big as yours--but close.   How long a video did you shoot?  I'm thinking 5 minutes at 30fps--I don't want to run out of disk space though--maybe 2 minutes is enough?  I have no clue.  Seeing is suppose to be average (rarely gets better here so its exciting even though its only average).  If seeing were better, I could use the 4X powermate and really have some fun.  I guess I could try it--not that big a deal switching from the 2x to the 4x.  Or I could use the .7x reducer and the 4X powermate and get 2.8x--not sure if all that glass will dim out the image.  

 

Thanks for the Pic.  It is amazingly clear.

Capture time is dependant on focal length but 5 mins would be too long. Memory is a bit vague on this as it was 2 years ago, - but I think it was around 90 secs. You can of course de-rotate in Winjupos but this is a bit advanced for novices. Use your 2x barlow if seeing is good enough and capture for around 100 secs. If seeings not good go down to native fl and capture some moons aswell if they're close enough. Make sure scope is well collimated and cooled. Don't use the reducer, - too much glass! Not sure of pixel size on your camera but mines aound 3.75 microns, so if similar then these settings will be fine.

Regards

Harvey

[Rodd]

14 minutes ago, Barv said:

Capture time is dependant on focal length but 5 mins would be too long. Memory is a bit vague on this as it was 2 years ago, - but I think it was around 90 secs. You can of course de-rotate in Winjupos but this is a bit advanced for novices. Use your 2x barlow if seeing is good enough and capture for around 100 secs. If seeings not good go down to native fl and capture some moons aswell if they're close enough. Make sure scope is well collimated and cooled. Don't use the reducer, - too much glass! Not sure of pixel size on your camera but mines aound 3.75 microns, so if similar then these settings will be fine.

Regards

Harvey

Mine in 5.6 microns--should work fine--Thanks for the tips--I guess 2,700 frames is enough!--I think I can shoot as high as 120fps if need be.  Would it be better to take 9 10 sec videos or 1 90 second video?  Or doesn't it matter.  I'm thinking a bit more control with several vids, but I don't know it that will complicate stacking and processing, which I am assuming will be easier than Seep space processing (talk about frustrating)

[Barv]

Ah, your pics will be smaller then because of pixel size. All very experimental I'm afraid but take single long avi's. no point in taking 10 sec ones. Don't just shoot as fast as you can but experiment with gain and exposure timing. The best images don't necessarily come from the fastest exposure times! Get the pic on the monitor as good as you can then shoot. Make sure you don't interfere with Gamma either. Good luck! Look forward to seeing your results!

Harvey

[Drop Of Sun]

I'm more into lunar but +1 for the SCT, aperture is king for closer up detail.

[Rodd]

34 minutes ago, Barv said:

Ah, your pics will be smaller then because of pixel size. All very experimental I'm afraid but take single long avi's. no point in taking 10 sec ones. Don't just shoot as fast as you can but experiment with gain and exposure timing. The best images don't necessarily come from the fastest exposure times! Get the pic on the monitor as good as you can then shoot. Make sure you don't interfere with Gamma either. Good luck! Look forward to seeing your results!

Harvey

As it was explained to me, image size will be dependent on focal length and sensor dimensions (total number of pixels)--but individual pixel size should not effect image scale.  I think the Skyris sensor is 640x480.  Anyway--we'll see if they were right in a few hours.