GSO CF RC8 or Skywatcher CF f4 Newt - Page 2

Crushellon (Tim) · #21 14-08-2016, 02:35 PM

I was hoping to spend $1600 on a camera, I could push it up to $2000 if I had to. Needs to be a compromise of being good for both scopes but leaning towards better performance for the rc8 over the ed80(will be running the ed80 with the sw 0.85 reducer/corrector) as the rc8 will generally be the main scope.

Crushellon (Tim) · #22 14-08-2016, 04:41 PM

http://www.bintel.com.au/Astrophotog...oductview.aspx

Looks pretty good? $1k over budget new but if I found a second hand one... With 5.4 pixel size it would be OK for both the rc8 and ed80?

codemonkey (Lee) · #23 14-08-2016, 04:54 PM

Probably a reasonable compromise. Those are very different focal lengths so you're not going to get one camera that's perfect for both.

It'll still be tough on the RC8, but it's likely to be a bit undersampled on the ED80. You could use the RC8 on the good nights, the ED80 on the bad nights, and maybe drizzle the ED80 on a typical night.

Someone has a mono SBIG 8300 (that Atik 383 you linked to is the colour version of the sensor) for $1600 at the moment. With the extra money you could put it towards a filter wheel and some filters and end up with a better rig.

http://www.iceinspace.com.au/forum/s...d.php?t=146551

Crushellon (Tim) · #24 14-08-2016, 05:33 PM

I'm a married father with 3 children under 4... Mono is out of the question for me, especially because my setup gets set up and packed up every night. It has to be OSC... As much as I would like the optimal results that I would get with mono+filters I just don't have the time. Maybe in 5 years when I have an observatory in the backyard

codemonkey (Lee) · #25 14-08-2016, 05:36 PM

With an automated filter wheel it won't make a difference to overall time. In fact, you'll get better results in the same amount of time. That said, it does require more effort in post processing, and maybe you're not prepared to do that. Fair enough, just a thought!

Crushellon (Tim) · #26 14-08-2016, 05:42 PM

Spending prolonged periods doing post work is fine... I can point from my computer chair

however I was under the impression that it takes 2+ nights with impeccable guiding for super long subs to get anything to work with doing mono/filter work? Which would mean setup/packup/staying up to monitor the weather for multiple nights. Don't get me wrong, the kind of results that you get with said type of setup is exactly what I'm after long term. But I don't think I could pull off the multiple nights working to get anything worth working on at this point with kids to look after.

Atmos (Colin) · #27 14-08-2016, 06:02 PM

In that respect OSC and mono are exactly the same, the amount of integration time needed that is. For instance:

20x180s with an OSC is a total of 1hours exposure.
5x180s LRGB is the same integration time but will be of higher quality. It will have a higher resolution due to not having a bayer matrix and you can capture straight luminance for detail and brightness.

There is no guiding difference nor any single sub length difference between mono and OSC. This is largely determined by your sky brightness (moon and light pollution), the focal ratio, pixel size and camera read noise.

NGC 6822 from my last imaging run a couple of weeks ago. This is less than two hours worth of data and the vast majority of that is just luminance (tossed out most of my colour data and half of my luminance). It could certainly do with a LOT more data but so would a OSC camera at 1.8 hours

One of the benefits of a OSC is that you don't have to worry about how many of each filter you get. I cannot comment too much on OSC imaging as I have done VERY little of it, I jumped straight into the deep end, was a struggle at times but I haven't regretted it.

Crushellon (Tim) · #28 14-08-2016, 07:00 PM

Orly? Intriguing. So say I did get a mono camera... Can I just use it without any filters for black and white photography while I save up for filters/filterwheel?

lazjen (Chris) · #29 14-08-2016, 09:01 PM

These might do to start with for filters/filterwheel:

http://www.bintel.com.au/Astrophotog...oductview.aspx $149
http://www.bintel.com.au/Astrophotog...oductview.aspx $149

You'd have something to at least play with to learn the ropes further.

codemonkey (Lee) · #30 14-08-2016, 09:35 PM

Quote:

Originally Posted by Crushellon

Orly? Intriguing. So say I did get a mono camera... Can I just use it without any filters for black and white photography while I save up for filters/filterwheel?

For OSC you're trading resolution and the ability to do narrowband for the convenience of capturing RGB data simultaneously. With an automated filter wheel you can get better data (in terms of both SNR and resolution) in the same time.

You can do B&W without filters, but the refractor at least will probably be performing less than is optimal that way, because the camera will capture a very wide range of light, and the refractor can bring only a subset of that range to focus which will make the images less sharp than ideal. The RC8 will be less affected due to the fact that it's got a mirror instead of lenses.

Don't get yourself a manual filter wheel if you need to be as hands off as possible, it's a waste of your money. Save the money and put that towards an automated filter wheel. Could be worth getting some of the cheap LRGB filters to play around with though.

You'll also need some software to control the filter wheel and do your image capture. I'd recommend Sequence Generator Pro. It's pretty simple to use, fairly powerful and much cheaper than the alternatives.

lazjen (Chris) · #31 14-08-2016, 09:50 PM

I have to agree an automated filter wheel would be better, but I think they're a bit of a jump in price from the manual versions.

Also, consider APT for image capture (http://www.ideiki.com/astro/Default.aspx), it's much cheaper than Sequence Generator Pro.

Depending on the gear you get and your computing skills, using ekos/INDI has an even better price point: free.

Atmos (Colin) · #32 14-08-2016, 09:58 PM

And a SBIG 8300C just came up too so its up to you

Crushellon (Tim) · #33 14-08-2016, 10:09 PM

So you guys have sold me on going mono.. Just as a 8300c came up for sale

now I just need my old gear to sell so I can buy one

I don't think my wife would appreciate me spending more money until some of it has gone

Oh and I already have the pro version of apt so all good for controlling it all. I am also gonna run the trial of maximdl on my next session to see if I can guide any better out of the box

lazjen (Chris) · #34 15-08-2016, 07:07 AM

Have you tried PHD2 for guiding?

Crushellon (Tim) · #35 15-08-2016, 08:46 AM

Yeh I've got an neq6 with belt mod and when I do the drift align with phd2 it's a nice straightish line and calibration is all good but I'm getting pretty average guiding with big spikes. Tried to do a pec with phd2 and ascom but the pec line was just oscillating up and down. So that was no good either.

Atmos (Colin) · #36 15-08-2016, 09:37 AM

Random spikes for me tended to mean that my mount needed a clean (regrease) as they disappeared after that. Unless there is an imperfection in the worm gear which will show itself every 7-8 minutes.

I've never done PE correction but my understanding is that it should go up and down

Crushellon (Tim) · #37 15-08-2016, 10:01 AM

Just did a clean out when I installed Te belt mod, results were better but still not quite good enough. Was only getting 50-60% usable subs at 120sec. I thought a pec line was suppose to look like a sine wave?

Edit: mind you the only time I've run it since the belt mod was in the field whilst trying to capture, I'm yet to sit down with it for a night and just play with guiding to get it better.

Crushellon (Tim) · #38 17-08-2016, 12:18 AM

So I ended up getting the stf-8300m off the forums and and a cheap set of Lrgb filters and a manual wheel. Do You need to run an IR filter in front of the color filters when using the ed80? The cheap filters didn't have the IR coating that the more expensive ones mentioned. Also would a cheap CLS CCD filter be better than a cheap luminance filter for working in suburbia?

Slawomir (Suavi) · #39 18-08-2016, 06:49 PM

Congratulations Tim- we look forward to seeing your images taken with your new gear

I would also pick a mono over osc any time

As for combining filters- I think experimenting will allow you to optimise your particular setup, but I personally would avoid using two filters at the same time (reflections?). Also, I do not expect there would be a significant difference in data collected through a cheap CLS and a cheap Lum filters.

Having said that, I would hold off and save for a good Lum filter, as it plays a vital role in collecting quality data for the final Tri-colour picture.