I have recently decided to upgrade my existing setup to better enable astrophotography. Given the wealth of experience on the forum, any advice would appreciated.
In 2010, I bought a Meade 8" LX90 which has been excellent for both visual and basic astrophotography. Long exposure astrophotography has always been on the cards and now seems like as good a time as any to "bite the bullet" and upgrade.
I would like an all-round setup which is as future proof as possible. I currently use a Canon EOS 550d and will continue to use this camera with the new setup (at least in the short term).
For the mount, I have decided on the Skywatcher AZ-EQ6.
For the telescope, I have been considering a number of options:
1. Defork the LX90 and mount the OTA on the AZ-EQ6
- Buy an OAG for guiding in order to reduce differential flexure and issues around mirror flop (the LX90 doesn't have a mirror lock). Bintel suggested the Orion OAG. I have also read that mirror flop is not too much of an issue on the 8".
The pro's and con's of this option include:
Pro: Can re-use my existing LX90 telescope which is an excellent scope;
Pro: Good for galaxies given the long focal lenth of the LX90 (I am keen to image galaxies)
Con: Will de-value the LX90 and the mount will essentially be wasted.
The total cost of this option is around $2700 for the new mount, OAG and Guider (Orion SSAG??)
2. Buy an ED80 and mount it on the AZ-EQ6
- Buy an ED80 with a guidescope / guider for autoguiding (Orion Mini or Awesome package).
The pro's and con's of this option include:
Pro: Keeps the LX90 whole (telescope and mount). The LX90 can be de-forked at a later stage if it makes sence.
Pro: Good for wide field astrophotography
Con: Not good for galaxy imaging.
The total cost of this option is around $3700 for the new mount, ED80, Autoguider package
3. Any other options
- Any other options which people may recommend as a good upgrade for astrophotography.
I understand that there is no simple answer and the question has been asked many times before however any advice, experience or recommendations would be greatly appreciated.
I'd go option 1 initially - that is essentially what I am thinking as the next step for my Celestron 8" SCT -- whack it on a AZ-EQ6 and add some sort of guiding (OAG or guidescope). Then at a LATER date I'll upgrade my imager and get a beautiful new APO. Stepwise investment is the key, to both allow you to increment your skills, and to make it easier to 'sell' the purchases to the wife
Hi Guys,
You may find that the SSAG isn't sensitive enough to use with an OAG.
I use the orion SSAG with a seperate guide scope (orion ST80) and find this works well.
The other night I tried the SSAG with an OAG and found that I couldn't see any stars. I swapped the SSAG with a lodestar and had stars immediatly.
Another alternative is the QHY5L2 which is very sensitive and would be a better option than the SSAG.
Hi Mark,
My two cents:
I can recommend EQ6/ED80 combo as it is a proven starter kit (for me anyway ). The EQ6 SHOULD handle your SCT and ED80 (Nico13/Ken) had one on a side by side setup with the same scopes (though I think he moved to a piggy back setup recently). Meade SCTs are heavier than Celestron SCT for the aperture.
I recently moved to a C8/ED80 piggy back option (see this thread http://www.iceinspace.com.au/forum/s...d.php?t=120026)
I would also recommend you getting a focal reducer (f6.3) for your SCT if you want to image through it to minimise frustrations.
In summary, I would:
1. Get the EQ6/ED80 combo and start doing wide field with your DSLR.
2. Once you get the hang if it, defork your LX90, get a focal reducer and mount it on the EQ6 and use ED80 as guidescope.
Cheers
Bo
Well, you are going to get the mount either way, so get the mount
Re the scopes, I would defork the LX90 AND pick up a 2nd hand ED80.
A 2nd hand ED80 can be had for around $300 or so, A dovetail to suit the LX90 is $110, so it doesn't come to much. i.e. about $500 on top of the cost of the mount, and you can use both scopes.
Don't worry about an OAG initially until you have come to terms with the new mount etc.
When ready to look at an OAG, I would look into the QHY5L-II (or the chinese equivalent) as it is way, way more sensitive than the SSAG, it is up there with the Loadstar for sensitivity for guiding (I owned both). The SSAG isn't really up to the job for the LX90.
It isn't too hard to modify the LX90 to fix the mirror flop problem, if you are comfortable pulling it apart. (There is usually very little anyway on the 8")
A simple focuser mod might even be enough http://jan.eaglecreekobservatory.org/focuser.html
You will probably get something back (at least a few $$) by selling the LX90 mount itself.
Thanks for all the great advice.. After a year (at least) of thinking about an upgrade, I finally bought an AZ-EQ6 today and de-forked the LX90.
Attached are some pictures of the deforked LX90 and the new AZ-EQ in boxes. I will setup the new mount tommorow and create a new "unboxing" thread with pictures for those that may be interested in the AZ-EQ6.
Quote:
Originally Posted by Poita
Well, you are going to get the mount either way, so get the mount
Re the scopes, I would defork the LX90 AND pick up a 2nd hand ED80.
Don't worry about an OAG initially until you have come to terms with the new mount etc.
When ready to look at an OAG, I would look into the QHY5L-II (or the chinese equivalent) as it is way, way more sensitive than the SSAG, it is up there with the Loadstar for sensitivity for guiding (I owned both). The SSAG isn't really up to the job for the LX90.
Peter - Thanks for the advice. I decided to just start with just the mount and will buy an OAG / guider once I have the mount, polar alignment, software etc.. sorted out. Lots of reading and learning to be done...
Quote:
Originally Posted by traveller
Hi Mark,
...Once you get the hang if it, defork your LX90, get a focal reducer and mount it on the EQ6 and use ED80 as guidescope.
Cheers
Bo
Thanks Bo - I agree that the focal reducer with the LX90 is a good idea. I will probably get the Optec Lepus at some point in the future. I believe this is one of the few reducers that works well the Meade ACF optics.
Quote:
Originally Posted by Amaranthus
I'd go option 1 initially - that is essentially what I am thinking as the next step for my Celestron 8" SCT -- whack it on a AZ-EQ6 and add some sort of guiding (OAG or guidescope). Then at a LATER date I'll upgrade my imager and get a beautiful new APO. Stepwise investment is the key, to both allow you to increment your skills, and to make it easier to 'sell' the purchases to the wife
??
Thanks Barry. I ended up taking option 1. Looks like we have similar equipment and idea's around incremental upgrades. I agree that an APO would be an excellent addition to the scope family.
Quote:
Originally Posted by scagman
Hi Guys,
You may find that the SSAG isn't sensitive enough to use with an OAG.
I use the orion SSAG with a seperate guide scope (orion ST80) and find this works well.
The other night I tried the SSAG with an OAG and found that I couldn't see any stars. I swapped the SSAG with a lodestar and had stars immediatly.
Another alternative is the QHY5L2 which is very sensitive and would be a better option than the SSAG.
Cheers
Hi John - thanks for this excellent advice. I decided that the SSAG may not be sensitive enough and that either the QHY5L2 or Lodestar would be a better choice. Once I get the mount sorted out, I will then consider which OAG / autoguider to go with...
I'll be really interested in how it goes, Mark. With the belt drive and PEC on your new mount, you may even be able to get subs of a few minutes without guiding?
The QHY5L-ii doubles as a good cam for a bit of planetary imaging if you're so inclined too. And depending on the prevailing exchange rate, you might find the QHY to be cheaper onshore than importing the other Chinese equivalent
Since getting the new mount, I have taken it out 3 times with the aim of getting polar alignment worked out.
After struggling to get an accurate polar alignment using Alignmaster, I decided to give drift alignment a go and after a few hours (actually many hours) of persistance last night, I managed to get a pretty accurate polar alignment.
Attached is my first test image taken with 10 x 1 minute un-guided subs on the new mount. Pretty pleased with the nice round stars. The full moon didn't help the nebula, but at least it provided an opportunity to test polar alignment.
Looking foward to the new moon to really test the new setup and hopefully get some nice galaxies.
Hi Dunk, Drift aligning is not hard at all. Pretty much point telescope east roughly 30deg above horizon. If using a cam, start a 35sec exp, wait 5secs, at guiding speed, move mount using ra controls for 15 secs, then reverse direction for the remain in 15secs. The image will show a star trail in a "V" pattern. The gap is how far out your PA is. So adjust your Alt manual adjustment a little. Then repeat the above exp/move again. If you have adjusted the mount in the right direction the gap in the "V" should have gotten smaller, if bigger you've adjusted the mount in the wrong direction. Make approriate adjustments again. Continue untill you get a straight line. Then slew to about dec zero and repeat but this time ajust the azimth and repeat till line is straight.
Go longer exp. for a better PA. The reason for the 5sec pause means you can tell which line is which as on will have a blob at the start.
Well, I ordered the AZ-EQ6 GT today, so I'll shortly be following in your footsteps, Mark! I plan to use it to mount my C8 OTA for AP, and my new ED80T CF. Will be fun to try out the AZ mode with both attached too!
Well, I ordered the AZ-EQ6 GT today, so I'll shortly be following in your footsteps, Mark! I plan to use it to mount my C8 OTA for AP, and my new ED80T CF. Will be fun to try out the AZ mode with both attached too!
Congratulations Barry
It is very solid mount and no doubt you will get many good years of use from it. I would also be interested to hear your experiences with the setup and on-going use given that we have a similar setup.
Are you planning to control the mount from the SynScan handcontroller or via a PC? I wanted to control the mount via the PC, so I also got the USB cable for the mount (http://www.bintel.com.au/Mounts---Tr...oductview.aspx). Even though the description says it is for the EQ5, it is also the right cable for the AZ-EQ6.
The software took a little bit of time to understand and setup, but it is nice to control everything from the PC (Mount, Camera, Planetarium Software etc..).
Looking forward to hearing how you go with the setup..
Thanks Paul.. I am hoping that I will be able to get slightly longer unguided subs before I need to consider an autoguider. Hoping that 2 mins may be possible, but understand that that is probably pushing it.
Quote:
Originally Posted by Camelopardalis
Wow, nice... how hard is the drift alignment?
Thanks Dunk. I found that the drift alignment is not so much hard as tedious (especially to get it accurate). I have spent alot of time reading up on drift alignment, so the theory made sense but in practice there are alot of things to consider - actual location in the sky to find the right stars for aligning, direction of the alt/az knobs to adjust, the size of the adjustments etc..
I was hoping to use software to automate some of the process, but when I tried Alignmaster I got inconsistent and strange results. This is probably user error, but I didn't want to debug software issues. I knew that drift alignment would definately work even if it takes more time than a more automated approach.
I have also previously found a good drift alignment simulator on the internet which was good for practice. I think the simultor is for the northern hemisphere, but it is still good practice. The original website for the simulator has been taken down, but someone at least had the foresight to relocate it to another website - http://astrophotographyonabudget.blo...alignment.html
Quote:
Originally Posted by Amaranthus
Wonderful! I was going to ask how it was going.
I'm thinking that once you get drift alignment down pat, it might only take 10 min or so - even quicker if you can set out markers for your tripod.
Thanks Barry. Hopefully the whole setup can be streamlined. Either way, I have decided that patience is probably a good quality for astrophotograhy. It is all part of the fun. The dog is also good company and seems to like astronomy Also good for advice when I got stuck, although the response wasn't always as helpful as I hoped :-)
). The EQ6 SHOULD handle your SCT and ED80 (Nico13/Ken) had one on a side by side setup with the same scopes (though I think he moved to a piggy back setup recently). Meade SCTs are heavier than Celestron SCT for the aperture. 
Also good for advice when I got stuck, although the response wasn't always as helpful as I hoped :-)
