4x Powermate or planetary camera?

[that_guy]

So ive recently moved to a new house that has a very bright lamp drowning out anything worth imaging. So im thinking id try my hand at plametary imaging with the ed127. My question is, should i get a powermate and use it with my 5d or should i get a camera with a smaller sensor? Something like a zwo planetary (good thing is that id be able to double up and use it as a guidecam when im out at a dark site).

Thanks in advance.

[Camelopardalis]

Tony, I'd vote for a dedicated planetary cam...they're more sensitive and support much higher frame rates.

Also, don't get caught up in the powermate slippery slope...sure they're nice, but a good barlow will do just as well with a planetary cam as the sensors are so small...shouldn't have to worry about CA across the field!

Personally, I'm a big fan of the ASI224MC...it's OSC which is easier to use. The ASI290MM is also a firm favourite of those more advanced than I...

[muletopia]

A different take to Dunk.
I have used a 4X powermate behind my Mewlon 210 to capture Saturn and its rings.
Camera ZWO ASI120mm
Capture program Sharpcap
A small field of interest gave a frame rate of about 120 fps.
The field contained the rings with just a little to spare.

Caveat, I live at an absolutely dark site and the seeing was very good that night.

Just to consider,
Chris

[AstroApprentice]

I've found the following calculator useful for modelling different scope/cam setups
http://astronomy.tools/calculators/field_of_view/

[that_guy]

Thanks guys, I'm currently looking at the 120mm or 120mc from bintel. They both have their pros and cons so will do a bit more research :)

[Camelopardalis]

The 224 and 290 are waaaaay more sensitive, if your pocket(s) is deep enough. May be worth it given you're chasing these things without a big reflector...but that's just MO ;)

[that_guy]

aha way ahead of you dunk, I was thinking of getting the 120mm with the filter kit but saw the 224mc for cheaper so ordered it directly from zwo.

[that_guy]

Correction, i ordered the 290mc. Also a club member was selling a c8 for $300 so i also grabbed that :D all ready for upcoming jupiter season

[Camelopardalis]

:thumbsup:

[Saturnine]

You should be happy with the ZWO290mc, I've been using one for about a year with my 127mm triplet or 200mm f6 newt and 2.5 X Powermate and am more than pleased with some of the results I've managed to get.
Really looking forward to planet season this year now I'm more familiar with my set ups and processing.
Have fun working out the best focal lengths , camera resolutions etc and , yea, I was eyeing off that C8 myself, was almost too good to pass up but someone got in quicker, congrats.

[that_guy]

Aha, i was also too late to pick up the c8 listed here. The c8 i bought was listed in our local clubs newsletter :p. Do you have any sample images taken with the 127 and 290mc? I have the same size scope and was wondering how images would look.

Thanks

[Saturnine]

Hi Tony
I should learn how to upload images to this site, a few I've taken are almost worth displaying in public. At the moment I'm too tired, been doing a lot of digging the past week, not good at my age. I'll have a go tomorrow when more bright eyed and bushy tailed.

[Camelopardalis]

Pitching a 5" 'frac against a C8 is an interesting experiment :D

[that_guy]

I do have them both now aha. One of the other reason for buying the c8 is that the 127 doesnt come in to focus with an eyepiece unless i switch out the focuser (a hassle in the field) and it's a bit too long to observe as it can get to awkward places. For field nights and public viewing nights, the C8 will serve well showing planets to the public while not having to do yoga to reach the eyepiece. :) Will report back once I pick up the scope today

[Camelopardalis]

Yeah the C8 packs some aperture into a might convenient little package.

Pay particular attention to collimation - it's easier than a newt as there is only the secondary adjustment but it's very sensitive when approaching spot-on...and it can make all the difference.

SE QLD makes for reasonably stable thermal conditions for a SCT since the temperature doesn't change all that rapidly, at least, until winter. You will want to devise a cooling solution before we hit peak planetary season. I have the Edge HD 8 with vents that have been fitted with fans and in winter they can be invaluable around dusk when the temperature drops 10-20 degrees in the space of a few hours.

Given you bought a 290, I'd suggest you leave the Barlow out to start with, and practice with getting the object on the very tiny chip at long focal length... I'd almost forgotten how much fun that is :lol:

Good luck - and enjoy :D

[that_guy]

I'm so used to platesolving for framing with DSO objects and a wide field of view. I'll have to get out my telrad finder from storage and learn how to do it the old fashioned way all over again.

[Camelopardalis]

You'll need more than a zero magnification finder at that focal length :eyepop:

Maybe strap the 127 to the top?

[that_guy]

I have an ed80 that i might chuck on the top. But for now, ill just do it the old fashioned way with a finderscope

[Camelopardalis]

Good luck :thumbsup:

[that_guy]

Quickly set up the c8 to test it out. The moon is SHARP in this thing. There are some smudges on the plate as well as the mirror but they dont seem to be affecting the image. However, I'll want to get them cleaned later on just in case. I have the scope still set up outside for jupiter if it stays partially clear and i dont pass out from exhaustion. I'm sure the images will be even sharper once the scope had time to cool.

[Saturnine]

Hi Tony

Hopefully some images will attach to this showing what the 127 triplet and ZWO290mc is capable of. Of course , as with planetary imaging, the seeing is most important to good results.
All the images were taken using an 2.5X Powermate as well and usually the best 500 frames of 2000 / 3000 frame avis' stacked in Registax.

[that_guy]

Those are very nice and sharp. I really love the close up moon image. One day I'll do a side by side comparison with the ed127 and the c8.

[Saturnine]

Glad you liked them, it's not often is the seeing co-operative in my area and it is one thing that worries me for Mars season this year. Mid July is when we usually get the worst of the jet stream, so I may have to do a few expeditions further north to get better conditions and hopefully I may have an 250mm newt to use by then.
I'm sure your C8 should get you some decent images, though the dreaded central obstruction may reduce contrast, enjoy using the gear, that's the main objective.

[Camelopardalis]

Damian Peach doesn't seem to think the central obstruction is too dreadful ;) :lol:

[Saturnine]

Yes , I'm aware of Damian Peach, Thierry Legault and lots of others that use SCTs' for lunar & planetary imaging and the excellent results they obtain. Aperture and seeing and attention to fine focusing are the main criteria, goes without saying I guess.

[that_guy]

On that note, is it worth getting a separate focuser for the imaging train? Like a rack and pinion?

[Merlin66]

Coming in late....
A x2.5 PM or a good x3 Barlow will get you into the optimum focal ratio with the C8 (rule of thumb - focal ratio= x5 pixel size.)

[Merlin66]

Re focuser
I’d recommend the JMI focuser motor.
The mirror slop on my C11 is minimal, and the JMI I use is controlled from my computer via the Shoestring adaptor. Works 100%

[Camelopardalis]

Nah, I wouldn't bother, but motorising it like Ken suggested saves a lot of frustration when you're trying to nail it :thumbsup:

[edwardsdj]

Awesome! I have obtained some very detailed images of Jupiter with the C8 in the past just using a cheap webcam. With the ASI290MM I'm sure you can get some amazing results!

Collimation of SCTs is absolutely crucial for planets (both imaging and visual). The difference between collimation being close and sensibly perfect is huge for planetary images. I used software to assist with collimation for the best images I was able to obtain.

Take care,
Doug

[edwardsdj]

I have had good results planetary imaging with the stock C8 focuser. It is a world of frustration though. Since upgrading to a Moonlite Crayford focuser for SCT I haven't looked back. Absolute joy to use.

I have no experience with the Moonlite on the C8 though as the flange I have only works with my C11 and C14.

I'd live with the stock focuser for a while and upgrade if focus is the thing frustrating you the most.

Take care,
Doug

[that_guy]

Ive had a chance to use both scopea but had some difficulty with the c8. How do you guys go about framing planets in the fov with such a small sensor and long fl. It took me nearly an hour just to find the damned planet and focus it.

[Merlin66]

I use a flip mirror.
Identify the field, move the object to the centre (or better use a c'wire eyepiece), flip the mirror and the object should be central with the CCD chip.

[edwardsdj]

I was able to get quite good at it using the stock finderscope. It was a matter of precisely aligning the finder after finding the planet the first time. Once you get a feel for where the focus position is and get the finder very accurate it gets much quicker to locate the planet again. As always, you can get accessories to reduce the frustration.

[ZeroID]

Pre-align them during the day if you have a good long distance target. I use a power pole on a ridge about 5 km away. Saves frustration on the night.
But the flip mirror is brilliant. I have one on the Lunt\ZWO 1600mm-c optical train and for centering and finding it's excellent. Fortunately the Lunt has plenty of focal range adjustment to cope with my experiments.