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Inverted
sage
*****

Reged: 01/19/13

Loc: LP Land
Back to imaging - what to get? new
      #5632972 - 01/20/13 11:00 AM

Hi all,
I was into AP for a a number of years, but got out for a while. I've owned DSLRs, Meade and Orion CCDs and tried a few other higher end ccds here and there. I am in the city though now and figure I will mostly be limited to NB. I like wide field AP a lot, and would really like more portability, so, would also prefer to do AP with smaller refractors and camera. I have an EQ6 with EQ Mod. I also have an orion guider a short tube 80, an 80mm WO ED and a R200ss.

I'm trying to decide what else to get to star off and to plan for the future and could use some help. I do also have a Cannon EOS lens adapter and like the idea of small wide field lenses. As I mentioned, I'd like to keep things simple and portable. One thing I am worried about with camera lenses and NB would be focusing though. IIRC it was tough even with the 80mm.

Also, I was looking at the new Orion finder scope/guide scope, it seems, replacing the short tube 80 with that could really help with the weight.

To the mount, the EQ6 is pretty heavy, I do see iOptron has some new mounts, that appear lighter, but not sure if they are any good (sorry, no AP in my budget )?

And of course I need a CCD, as I don't have one now. It looks like my budget would be something like a lower end 8300 chip, or something like an Atik 428ex or 450, but that would be on the high end. I do like the low noise of the Sony chips, but don't like the small size and tiny full well capacity, always seems like the stars are so big relative to the image scale. Not necessarily taking darks is nice though and having low read noise, so, I can spend less time drift aligning and just stack more shorter exposures would be nice. The 8300 chips also seem like a good bang for the buck, but higher read noise and dark noise. Wider field though., which I like.

Also, at this point, I should mention, I won't be getting everything at once. I plan to buy in stages, with a ccd being the first. I do also have a modded DSLR, which I'm thinking if using for color, rather than buy a separate filter wheel and filters. I definitely want a mono ccd though.

So anyways, this post is just to introduce myself and ask for a little advice to get re-started. Help me decide which direction should go. Also, certainly feel free to critique my plan and help bring me back to reality if anything sounds unrealistic


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orion69
scholastic sledgehammer


Reged: 05/09/10

Loc: Croatia
Re: Back to imaging - what to get? new [Re: Inverted]
      #5633002 - 01/20/13 11:15 AM

I would sell Orion finder scope/guide scope and get OAG.

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Inverted
sage
*****

Reged: 01/19/13

Loc: LP Land
Re: Back to imaging - what to get? new [Re: orion69]
      #5633085 - 01/20/13 12:14 PM

Thanks, Knez. I tried a OAG before, but had issues with back focus and finding guide stars. Have OAGs gotten a lot better in the last few years? Or is there particular one that really works much better than the old ones? Or if not, what is it about a OAG that really makes it worth the headaches? Small size? And/or less shift?


Also, how do you like the 383L+ ? That is on my short list.


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orion69
scholastic sledgehammer


Reged: 05/09/10

Loc: Croatia
Re: Back to imaging - what to get? new [Re: Inverted]
      #5633118 - 01/20/13 12:36 PM

OAG completely eliminates differential flexure. I use TSOAG9 because it has smallest backfocus. Downside is that you must have a decent guiding camera. That said, I never had problems with Alccd5 (Qhy5) camera which is considered not very sensitive with my F7.5 refractor. I switched to Lodestar which is much more sensitive and convenient.

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Inverted
sage
*****

Reged: 01/19/13

Loc: LP Land
Re: Back to imaging - what to get? new [Re: orion69]
      #5633579 - 01/20/13 05:10 PM

That does look nice. Not cheap, but definitely will look into it further.

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vpcirc
Post Laureate


Reged: 12/09/09

Loc: Merced CA
Re: Back to imaging - what to get? new [Re: Inverted]
      #5633968 - 01/20/13 09:42 PM

The need for OAG really depends on the OTA. If you're going to try image at a high F-ratio and an SCT by all means. If you're going to shoot widefield with a refractor or newt, you'd be far better to use a seperate guide scope. Guiding software has improved immensely, and OAG can make things a lot more difficult than they need to be. I'd worry about the mount first since you're buying in stages. The better the mount the better everything else will work, and less important guiding becomes.

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andysea
Pooh-Bah
*****

Reged: 09/03/10

Loc: Seattle, WA
Re: Back to imaging - what to get? [Re: vpcirc]
      #5634030 - 01/20/13 10:14 PM

I agree on the oag suggestion. It will make all potential guiding issues go away. I would use it on any focal length scope because its easy and it works. I suggest the qsi583wsg. It's an awesome camera and it has the low read noise that you need for narrowband. It also comes in an elegant package with integrated filter wheel and oag. Not cheap but. Worth the investment in my opinion. You won't have to deal with clunky filter wheels and separate oag's.

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vpcirc
Post Laureate


Reged: 12/09/09

Loc: Merced CA
Re: Back to imaging - what to get? new [Re: andysea]
      #5634079 - 01/20/13 10:42 PM

Quote:

I agree on the oag suggestion. It will make all potential guiding issues go away. I would use it on any focal length scope because its easy and it works. I suggest the qsi583wsg. It's an awesome camera and it has the low read noise that you need for narrowband. It also comes in an elegant package with integrated filter wheel and oag. Not cheap but. Worth the investment in my opinion. You won't have to deal with clunky filter wheels and separate oag's.




I'll be guiding a 12.5 CDK in 3 weeks with a 60 mm guide scope and an SBIG guide camera and will never have to worry about guide stars, a rotator or filters effecting the guiding or the "flexure" issue that's usually not the issue. I'll send a guide correction every 10 seconds, and I'll have nice round stars. Why? Because my mount is properly aligned and tracks with with such precision guiding plays into the equation as a very minor factor.


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andysea
Pooh-Bah
*****

Reged: 09/03/10

Loc: Seattle, WA
Re: Back to imaging - what to get? new [Re: vpcirc]
      #5634200 - 01/21/13 12:13 AM

On yes very good points.. Once you have a good mount it doesn't really matter how you guide it,

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freestar8n
Post Laureate
*****

Reged: 10/12/07

Re: Back to imaging - what to get? new [Re: Inverted]
      #5634336 - 01/21/13 04:07 AM

Hi-

I am a big fan of OAG, but if you plan to image with the R200ss, you may have limited backfocus for a good OAG. There are very thin OAGs such as the one mentioned above, but it doesn't let much light in from the guidestar compared to larger OAG's that take up more backfocus. The best one I have used is by Hutech, but it is expensive once you get adapters. Alternatively, many people in CN use CCD's from QSI that include an integrated OAG that may work with the r200ss.

A key to modern usage with OAG is to combine it with a planetarium program and field of view indicator so you can pre-plan the brightest guidestar and dial it in ahead of time. This means no searching for a guidestar. A sketch of the process can be seen at the bottom of this page.

Even with the ultimate high end mount - if you are guiding with a guidescope and there is differential flexure - your exposures will be limited by star trailing - particularly for narrow band work. In terms of flexure, the mount makes no difference except the star trails will be tighter and smoother - and if anything show up worse in long exposures.

Although I mainly recommend OAG, there is a completely new way to guide with a guidescope that greatly reduces flexure in both simple and high-end setups - and it is based on free software. It is called FlexRX and it is described here. This approach is based on guiding with MetaGuide, which I wrote. FlexRX is fairly new but the results are promising - and it would let you get started with the equipment you currently have - so you could give it a try. It also works very well with comets - and there are possibly some big ones on the way.

Frank

Edited by freestar8n (01/21/13 04:24 AM)


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alpal
Post Laureate


Reged: 06/15/09

Loc: Melbourne Australia.
Re: Back to imaging - what to get? new [Re: Inverted]
      #5634365 - 01/21/13 05:49 AM

Quote:

would also prefer to do AP with smaller refractors and camera. I have an EQ6 with EQ Mod.
I also have an orion guider a short tube 80, an 80mm WO ED and a R200ss.

I do also have a Cannon EOS lens adapter and like the idea of small wide field lenses.

To the mount, the EQ6 is pretty heavy, I do see iOptron has some new mounts, that appear lighter, but not sure if they are any good






That should be pretty easy.
You have a good enough mount for short focal length work.
You can modify it to make it track even better as I did:

http://www.flickr.com/photos/24719437@N03/6001169049/in/photostream

You could get a QHY9 camera as I did complete with parfocal filters.
You wouldn't need an OAG for short focal length - just use a little guide scope & PHD guiding.

A bahtinov mask will help you focus.


The hardest choice will be what lens to put on the camera
& getting the right fittings to space that lens.
I couldn't tell you the answer to that - maybe others can?


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jmasin
Carpal Tunnel


Reged: 12/22/08

Loc: Murphy, TX (DFW)
Re: Back to imaging - what to get? new [Re: alpal]
      #5634617 - 01/21/13 10:02 AM

Good suggestions given. I agree with OAG; however, it's also true as stated this depends on the scope, and if your mount is nicely tuned guiding is less important. Still I like OAG even with my AP900 for ease, similar image scales etc. With the 2000mm RC, OAG still seems to be a must even with the AP900.

This may be obvious but I'll say it anyway - the easiest, shortest and most stress free route to AP is to keep focal length short. I started kinda backwards, started at 1100mm, went to 2000mm, picked up a 460mm etc... Many amazing images can be had at 4xx mm focal length, and it is SO much more forgiving of alignment, mount error etc. etc.

When I was starting this point was made on the forum, and I promptly ignored it thinking I'd start imaging tiny faint fuzzies right away That led to a year of significant frustration and more money spent.

Anwyay, I would recommend anyone new, or restarting build some momentum at shorter FL for a little while (analogous to that a reasonable image scale...)


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andysea
Pooh-Bah
*****

Reged: 09/03/10

Loc: Seattle, WA
Re: Back to imaging - what to get? new [Re: jmasin]
      #5634666 - 01/21/13 10:32 AM

+1 for shorter FL imaging. That is definitely the way to start! Plus there are fewer people doing really wide field work so your pictures will stand out more. Even a good 70mm lens will give you amazing results. I really enjoy shooting with my Canon lenses.

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Inverted
sage
*****

Reged: 01/19/13

Loc: LP Land
Re: Back to imaging - what to get? new [Re: andysea]
      #5634714 - 01/21/13 10:59 AM

Thanks all. I think at this point I would not use anything with a longer focal length than the R200SS, so 800mm max. Probably will do a lot with an 80mm refractor too and still thinking about lenses. As mentioned, I have an EOS lens to t-thread adapter and do have a number of spacers. I never got a lens to use with it though, but that would be fun to get going. It's easier to justify the cost of a lens if I can use it for daytime too... So, how is say the cannon 70-200 for AP? Other suggestions?

I think for a ccd, I'm leaning to words an 8300 chip, as that seems to be a good match for wide field short focal length imaging, and the binning sounds good if I move to longer focal lengths at some point.

My EQ-6 was hyper tuned by me and I did get a worm gear from Aeroquest machining at one point, so, it was pretty good for a synta mount. My biggest complaint was just that it is heavy to lug around.


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jmasin
Carpal Tunnel


Reged: 12/22/08

Loc: Murphy, TX (DFW)
Re: Back to imaging - what to get? new [Re: Inverted]
      #5634738 - 01/21/13 11:14 AM

I don't think you can go wrong with an 8300!

And my Atlas served me well for many, many years!


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andysea
Pooh-Bah
*****

Reged: 09/03/10

Loc: Seattle, WA
Re: Back to imaging - what to get? new [Re: Inverted]
      #5634946 - 01/21/13 01:11 PM

Quote:

So, how is say the cannon 70-200 for AP?




I really like my 70-200 f4. I also recommend the 400 f5.6.
If you decide to get the 70-200 f2.8 I would suggest getting the mark2 as they really improved its sharpness.
The 70-200 f4 however is really a bargain for what it can do. I recommend the non IS version.
I use Canon lenses a lot.
Here is my most recent shot with the 300 f4 IS.
http://www.flickr.com/photos/andyinsea/8400455013/in/photostream/
Unfortunately I have some flexure in that image which I think occurred in the lens collar (I discovered that I hadn't tightened it up all the way).
I find shooting with lenses a lot of fun! You can look through my flickr page for examples of what you can get with the different lenses.


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blueman
Photon Catcher
*****

Reged: 07/20/07

Loc: California
Re: Back to imaging - what to get? new [Re: andysea]
      #5635144 - 01/21/13 02:55 PM

Buy a good mount, plan on it being the highest cost item.
Buy a good APO refractor, figure it to be 2nd highest
Buy a good camera and filter wheel AND good filters. It will all cost about what the telescope did.
Finally, get a good small 50-60mm Borg Mini refractor and a nice guide camera.
Then buy MaximDL and CCDStack and of course Photoshop CS5 or later.
Now spend hundreds of hours learning how to get it all right. :^)
Simple, right?
Blueman


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LarsZ
sage


Reged: 01/12/08

Loc: Sweden
Re: Back to imaging - what to get? new [Re: blueman]
      #5635173 - 01/21/13 03:08 PM

An OAG will definitely give better guiding, but finding guide stars in a city with all the light pollution is quite a task.
I tried but gave up and went back to a small guide scope instead. When I go darker skies, I always use the OAG though.

/Lars


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andysea
Pooh-Bah
*****

Reged: 09/03/10

Loc: Seattle, WA
Re: Back to imaging - what to get? new [Re: blueman]
      #5635215 - 01/21/13 03:30 PM

Quote:

Buy a good mount, plan on it being the highest cost item.
Buy a good APO refractor, figure it to be 2nd highest
Buy a good camera and filter wheel AND good filters. It will all cost about what the telescope did.
Finally, get a good small 50-60mm Borg Mini refractor and a nice guide camera.
Then buy MaximDL and CCDStack and of course Photoshop CS5 or later.
Now spend hundreds of hours learning how to get it all right. :^)
Simple, right?
Blueman




Yes that sounds about right....I'm still working on the last part!


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Fogboundturtle
professor emeritus


Reged: 05/20/09

Loc: Burnaby, BC
Re: Back to imaging - what to get? [Re: andysea]
      #5635509 - 01/21/13 06:35 PM

CN always have the best advice. If I only listen to them more often...I am going CCD too. SBIG STF 8300 with OAG because it just an easier setup overall. Less time troubleshooting, more time photon capturing.

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