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Imaging with the Celestron AVX?

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#26 Jarrod

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Posted 02 July 2013 - 03:13 PM

What I can say for sure is that when I went to the Atlas, my pictures instantly improved. I'm sure I would have seen "some" improvement with the AVX. But at the end of the day, after reading a boatload on the new mount, I decided the Atlas was the way for me to go.


Your situation is very different from mine. I don't have an observatory, and I don't have another EQ mount. You wanted to upgrade from the CG-5 and I can see why spending $800 for a marginal upgrade to the AVX probably would not have been a good investment for you.

But I have nothing. Therefore I argue that spending $800 (currently $720) to get an AVX is infinity times better than my current situation.

Maybe the simplest answer is for me to give up on my desire to photograph galaxies if it isn't within my budget.

#27 Madratter

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Posted 02 July 2013 - 04:16 PM

What I would say, Jarrod, is that to some degree your budget requirements vary in terms of how patient you are.

I was able to image galaxies with the CG-5. Take a look at my gallery. And I'm sure the situation is better with the AVX. And again, look at the gallery of AVX images I sent you earlier.

But I did have to throw out a fair number of frames, and I did need to spend the time to polar align carefully. That will cost you time every time you go out without an observatory.

But it is doable. So the question is how patient are you willing to be?

Galaxies are not the easiest target, but the big bright ones aren't the hardest target either.

And I don't want to come off as selling myself as an expert on this stuff either. I am very much a beginner. I have dabbled with this in the past but only within the last 6 or seven months did I start taking this seriously.

The normal advice around here is to start with a short focal length refractor. I didn't go that route myself although I think it is excellent advice. If shooting galaxies is your deal, then shooting nebula might not do much for you.

I will tell you one big advantage of galaxies is that you don't need to mod your camera to shoot them.

#28 cn register 5

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Posted 02 July 2013 - 05:33 PM

Most of my imaging with the AVX has been with an 80mm ED scope (a Celestron Oynx) for imaging with a ST80 on a home made side by side mount for guiding. By the time the cameras, focuser and filter wheel have been added this lot comes to about 18 lbs.

I've never bothered with any of the precise balancing, levelling or polar aligning that so many people seem to think is essential.
My process is:
Put mount down on the patio with the legs more or less where they went last time.
Do a 2+3 alignment.
Do an ASPA
Train PHD.
Start imaging.

It's possible that this casualness helps because the mount seems to behave better if it isn't precisely balanced or polar aligned.

I apply PEC if I remember.

The combination of a fairly short focal length refractor and some sort of guider - and a lot of people use finder based guiders - seems to work very well for learning about astro imaging.

One useful source of information and images is the CelestronVX Yahoo group http://ca.groups.yah...up/celestronVX/

The people there are friendly, helpful and enthusiastic but not evangelists.

Chris

#29 terry59

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Posted 02 July 2013 - 05:38 PM


I've never bothered with any of the precise balancing, levelling or polar aligning that so many people seem to think is essential.
My process is:
Put mount down on the patio with the legs more or less where they went last time.
Do a 2+3 alignment.
Do an ASPA
Train PHD.
Start imaging.

It's possible that this casualness helps because the mount seems to behave better if it isn't precisely balanced or polar aligned.

I apply PEC if I remember.

Chris


Chris - Could you show something of your work please?

#30 cn register 5

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Posted 02 July 2013 - 06:13 PM

There's a horsehead/flame of mine somewhere on the massive AVX thread in the Mounts section. That's quite nice. Multiple 5 minute exposures with a Ha filter.

I've had very little time when it's been clear and I've been able to get outside with the scope. At the present in the UK it barely gets dark.

And I'm very reluctant to post anything on CN because of the overwhelmingly negative nature of most of the comments about any images, especially ones used to evaluate mounts.

My M51 rgb image which is the only image I've got with my 6" RC has no flats and as a result has a massive brown doughnut, dust circles and all sorts of artifacts. In fact, looking at it again, it may not have darks either.

Chris

#31 WarmWeatherGuy

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Posted 02 July 2013 - 06:38 PM

There's a horsehead/flame of mine somewhere on the massive AVX thread in the Mounts section. That's quite nice. Multiple 5 minute exposures with a Ha filter.

Chris


Found it click here.

#32 Jeff2011

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Posted 02 July 2013 - 07:13 PM

And I'm very reluctant to post anything on CN because of the overwhelmingly negative nature of most of the comments about any images, especially ones used to evaluate mounts.



Chris,

I have not found this to be the case. Most comments to my images and those of others have been constructive and encouraging in this forum.

I do enjoy an intense intellectual discussion like that has occurred in this post and I think that adds great value. If everyone agreed with everyone else, this site would be rather boring. Overall I think most people are civil and respectful to each other on this site even though opinions may be strong.

#33 Madratter

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Posted 02 July 2013 - 07:23 PM

There's a horsehead/flame of mine somewhere on the massive AVX thread in the Mounts section. That's quite nice. Multiple 5 minute exposures with a Ha filter.

I've had very little time when it's been clear and I've been able to get outside with the scope. At the present in the UK it barely gets dark.

And I'm very reluctant to post anything on CN because of the overwhelmingly negative nature of most of the comments about any images, especially ones used to evaluate mounts.

My M51 rgb image which is the only image I've got with my 6" RC has no flats and as a result has a massive brown doughnut, dust circles and all sorts of artifacts. In fact, looking at it again, it may not have darks either.

Chris


Your Horsehead is quite nice. :)

#34 CounterWeight

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Posted 02 July 2013 - 07:26 PM

I hope I'm not a part of that 'negative press'. I usually say that images are a poor measure of visual performance, worst of all for someone who has never used a scope - but that is not mount stuff IMO.

In the end, mounts, scopes guiders - my take on it is to think 'system'. As for the mounts contribution, it only needs to work in a way that gets you round stars - hopefully reliably, or at least in some ratio you feel justified for the $$ spent. The rest of making a good image, exposure time, calibration and processing and post processing is a different matter.

It's the tip of an iceberg, but IMO the significant part in weighing options with respect to the rest of a system. What is the 'budget breaker in it all' is buying something over again, though the used gear market is always active and you can recoup some at least.

As to the significance of auto-guiding/tracking it can help make a workable system better, but it has it's limitations.

IMO this level of imaging, the market is increasing options and iOptron seems pretty dedicated at making an impact, and mini-guiders are now here to stay. great news for us :)

When thinking about budget I think it's good to look for images like you want and look at the gear used to get it. Throw out the high and the low and in the middle is maybe a reasonable case.

I've been thinking about your mention of starting with two scopes and one for each type object and on the surface it is sound (within all the caveats that you're not expecting too much). Shopping the 'used' market will extend your astroca$h. You don't 'need' both scopes to get started. I think learning just one, and really learning that one could keep you busy for a good while depending on how much clear sky time and other free time for the processing of your data.

#35 cn register 5

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Posted 03 July 2013 - 02:46 AM

I should have mentioned that I used two 80mm scopes because I had them - and the cameras. If I was starting from scratch I would be looking at the finder-guider type of solution.

Let's see what people think, here's M51 - I think. It's a series of 2 minute exposures using RGB filters. Atik383L+ binned 2x2.

I've had to reduce the size from 1600 by 1200 to 800 by 600 to get the size down to what CN wants.

My concern about posting this was the pasting that Jason Ware got over some images with the LX850 he posted.

Chris

Attached Files



#36 CounterWeight

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Posted 03 July 2013 - 03:38 AM

Oh... yeah... well that is another story isn't it ;)

As far a judging the mount in this image - Stars look good here - detail and definition looks good in the galaxy - looks to me like the mount is doing it's job here.

#37 dr.who

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Posted 12 July 2013 - 12:36 AM

My two cents since I own two of the mounts and stepped down from a CGEM to the AVX because imaging with the bigger mount was no longer fun and the hobby is supposed to be fun... I have two of them by the way because once an imaging run starts I need something else to do while I wait. This way I have the Tak or 800 Edge doing its thing and I can view with the other or with the 1100.

It is a very capable mount for its price point. I call it the CGEM Lite in that it has all the great features of the CGEM at half the cost and half the weight. However you do pay a price in what it will hold. It will handle my 11" Edge without breaking a sweat for visual but going over an 8" SCT and you are looking for trouble in terms of frustration due to overloading the mount weight wise for AP. Same will apply with a big Newt.

If you are comfortable with a Newt in terms of collimation and want a good multi purpose scope (visual and AP) take a hard look at the David Levy Comet Hunter by Explore Scientific. It will handle imaging out of the case with little modification (I would replace the carry handle with a 7" Vixen rail so you can munt a guide cam easier) and it is $1,000 US. It's a fast scope with good aperture and will get you nebulae as well as galaxies.

If you are not familiar with Newts or are not comfortable with collimation )it is easier than people think) then start with an 80-90mm APO refractor like the Explore Scientific or the Stellarvue. The value add for the ES is again it is ready to image out of the case with extension tubes rotating focuser etc.

Once you have climbed the learning curve with the APO take a look at an SCT like the Edge 800 for the deep work on smaller fainter targets. With a focal reducer you will sit at f/7 1400mm and then natively at f/10 2032mm to go really deep on objects.

#38 frito

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Posted 12 July 2013 - 07:17 AM

I agree with everyone else, get a short FL APO/Semi-APO refractor to start off with, you can even get going without an autoguider at first as they are very forgiving compared to longer and larger focal length scopes when it comes to imaging. i'm currently getting 2 min subs outta my CG-5 with a 388mm 66mm refactor unguided, more than enough exposure time to get your feet wet and learn a ton about imaging before you spend big bucks on more equipment.

#39 DaemonGPF

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Posted 12 July 2013 - 08:04 AM

Most of my imaging with the AVX has been with an 80mm ED scope (a Celestron Oynx) for imaging with a ST80 on a home made side by side mount for guiding. By the time the cameras, focuser and filter wheel have been added this lot comes to about 18 lbs.

I've never bothered with any of the precise balancing, levelling or polar aligning that so many people seem to think is essential.
My process is:
Put mount down on the patio with the legs more or less where they went last time.
Do a 2+3 alignment.
Do an ASPA
Train PHD.
Start imaging.

It's possible that this casualness helps because the mount seems to behave better if it isn't precisely balanced or polar aligned.

I apply PEC if I remember.

The combination of a fairly short focal length refractor and some sort of guider - and a lot of people use finder based guiders - seems to work very well for learning about astro imaging.

One useful source of information and images is the CelestronVX Yahoo group http://ca.groups.yah...up/celestronVX/

The people there are friendly, helpful and enthusiastic but not evangelists.

Chris


Proper balance is not perfect balance on these mounts. You want a very slight bias on these mounts to preload the spur gears a bit.

#40 Jeff2011

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Posted 12 July 2013 - 12:36 PM

Proper balance is not perfect balance on these mounts. You want a very slight bias on these mounts to preload the spur gears a bit.



When I setup, I try to balance the RA axis with more weight to the east side based on the orientation of where the scope will be during imaging. For me it is hard to judge just how much. The other night I was imaging M8 and it crossed the meridian. The AVX mount won't do a meridian swap until it reaches a number of degrees past the meridian so I just let it keep imaging for a while longer. After it past meridian my PHD RMS when from 0.23 to 0.19. I thought it would have been worse. I was surprised.

For Dec, I just try to get a good balance while the scope is positioned to the approximate orientation it will be in when imaging. The Dec adjustments during guiding is no longer an issue for me. I just setup PHD to only send adjustments in one direction which for me is generally north. I first turn off guiding commands to see which way it drifts and then set it accordingly and turn the guiding commands back on. I may have to also crank up the Max Dec setting a while until the backlash is resolved and then I set Max Dec back down again. The ASPA seems to get me a very good polar align, but off just enough to cause a little bit of drift which actually helps with the guiding in one direction method.

#41 mpgxsvcd

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Posted 12 July 2013 - 01:11 PM

A refractor is definitely the safest bet. However, I still use a Newtonian with my CG-5 because it offers the best bang for your buck. If the CG-5 can handle the weight of the Newt then the AVX should be able to as well.

8" F4.0 800mm Newt $499.00
http://www.optcorp.c...tical-tube.html

I also would consider getting this RC(ritchey-chretien) if I was going to buy another scope.

OPT 8" F8.0 1600mm RC $899.95
http://www.optcorp.c...retien-ota.html

I would definitely get the field flattener/coma corrector for the Newtonian. That is an extra $100-$200. The RC is advertised as not requiring one.






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