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HELP! I need EAA for Dummies - Please don't drown me in technobabble

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#201 jgraham

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Posted 24 September 2016 - 11:00 PM

I am using the visual port which uses the internal diagonal.

 

I bought the 25' version of this cable...

 

https://www.amazon.c...ya_aw_oh_bia_dp

 

...and it worked great!

 

I just came in from a very successful evening of EAA observing using my ETX-80/RI2. I started at Altair, hopped southwards across Scutum and Saggitarius, then across Capricorn, Aquarius, and Pegasus, ending the evening at M33 in Triangulum. I located dozens of deepsky objects, only coming up empty on maybe 3 targets. I synched the mount on each object before moving on to the next and I only had to use the eyepiece on 3 occassions when I had to slew a long distance. Each time the object was within the field of the eyepice, but out of the field of the camera and it was easy to get it centered and to continue.

 

Overall, this system easily outperforms my 16" as far as what you can see, but of cours the view through the 16" is a very different experience so the two compliment each other nicely.

 

The ETX is a solid performer, but as I have cautioned above it takes a light touch and a bit of patience. Slow slew speeds (a setting of 3, 8x sidereal) and frequent synching helps to settle it down. You also need to fiddle with the camera settings to find what works. I spent most of the night in monochrome mode, with an exposure of 256 (about 5 seconds) and an AGC of 24. The color mode worked great on nebula like M8, 16, 17, and 20. For most other targets, including galaxies, I prefered the monochrome mode.

 

Soooo, it all seems to work as it is supposed to. The drives on the ETX really aren't up to the task of imaging, but they work well with the RI2. The RI2 is simple, effective, and very sensitive.

 

Fun stuff!


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#202 CA Curtis 17

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Posted 25 September 2016 - 10:12 AM

To clarify the in-camera feature on the R2 called DNR (called 3D-DNR on the R1 and other analog cameras) "averages' successive frames to average out noise which helps to smooth out the background and enhance detail.  It does not "add" successive frames which would also average noise but would also increase image brightness.  As each frame is averaged, the image improves until it reaches the number of frames you set DNR to and from then on is just a rolling average of the most recent frames.

 

As you guys are reporting here, the R2 performs very well without a computer, especially when using the DNR function.  However, if using an Alt-Az mount, you will find, depending upon the focal length that you are operating at, you may not be able to set the DNR to its maximum of 6 frames due to field rotation.  DNR does not rotate or align the internal frames.  With the 6SE at ~ f/4.5, I was often limited to 4 frames for DNR to avoid star elongation.  

 

When you move onto using a computer and something like Sharpcap, the software will rotate and align successive frames and, in this case, it "adds" those frames which gives the advantage of both noise reduction and increasing brightness. I was able to do more than 5min with the same 6SE setup without star elongation and got much more detail in my images.  But, keep in mind, there is no free lunch.  On an Alt-Az mount you still have field rotation so while Sharpcap takes care of that you do end up with black borders where the successive fields do not line up.  Not a big deal is you are just viewing, maybe a big deal if you are capture images but you can still crop this out.

 

Best Regards,

Curtis


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#203 jgraham

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Posted 25 September 2016 - 11:09 AM

True, but the general working space for altaz mounts is about 30 seconds before field rotation becomes apparent. This is a good match for the RI2 with its maximum exposure of about 5 seconds and its ability to average uo to 6 frames, which totals about 30 seconds. In my trials with my ETX-60/80 I ranged from just above the horizon to near zenith and I never noticed any affects from field rotation. I spent a lot of time with the camera in monochrome mode, the exposure fixed at 256, the AGC at 24, and sitting on the DNR menu with the DNT set to 0 until the image settled down and then I'd sneak it up to 3-6. If things got whacky I'd gi back to 0 to reset the stack. If I wanted to sit on a field for a while (the Swan Nebula was soooo beautiful!) I'd switch to color and back all of the way out of the menu system to clean up the screen. Having the screen on a little table with the controller right next to it was very comfortable. After a while I lost track of where in the sky the scope was actually pointing and I had to look up to see where I was at. :)

 

The RI2 is good at what it does; a nice, lightweight, simple video system. Nothing fancy, but very capable and a lot of fun.


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#204 jgraham

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Posted 25 September 2016 - 09:40 PM

The ETX is fun and it is amazing what you can do with it, but I wanted to move up a bit to something a little more conventional and something that I mentioned above; using a little 4.5" StarBlast on an LXD75 mount. I don't want to get too fancy as it gets to a point where I might as well set up my imaging gear, but this setup is still very simple and lightweight and is a great match for the RI2.

 

The system; a 4.5" f/4 Orion StarBlast (imaging version, I wanted to be sure to be able to reach the focus), an Orion 50mm RACI finder (eliminates the need to occasionally replace the camera with an eyepiece and allows star-hopping, very nice), an LXD75 (lightweight, accurate GoTos and tracking, slews with authority), a 25' video and power cable (gives good separation from the scope and moves the camera remote to the monitor), with everything powered by a single jumpstart battery.

 

LXD75 StarBlast RI2 (9-25-2016)-1.jpg

 

LXD75 StarBlast RI2 (9-25-2016)-2.jpg

 

I just came in from testing this under relatively poor skies; warm, humid, poor transparency. I did a similar walkabout as last night; Aquila south through Sagittarius, across Capricornus, Aquarius, Pegasus, and then on across Cassiopeia, and Cepheus. Simply amazing. One deepsky object after another, no non-hits. Some were tiny, some faint, some very low contrast, but I could not believe what I was seeing with a 4.5" telescope. The Bubble! NGC 7538! NGC 188! NGC 7479! Simply amazing! I'm going to ride this horse a bit further just to see what I can do, but I think that I have found my EAA-only setup. :)

 

Fun stuff!

 


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#205 Organic Astrochemist

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Posted 26 September 2016 - 11:53 AM

Great posts. I'm glad to see that you're having fun.

It would be nice to know if one can achieve focus with the Starblast 114 mm which is currently sold. In the image, the focuser seems out a bit, is that the position in focus? I think the imaging starblast has the same focuser but the primary was moved up. What are the dimensions of the 1.25" nosepiece of the R2? Did you try with and without the 0.5 reducer? Could you put a spacer between the camera and reducer? Could you use a focal extender screwed on instead? Thanks



#206 jgraham

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Posted 26 September 2016 - 01:37 PM

I have both the original StarBlast and the later imaging version. The imaging version was built with a larger diagonal and a closer primary/secondary spacing to move the focal plane outwards by about a centimeter (about 1/2"). The pictures above show the focuser in the focused position with the RI2. Based on my experience imaging with the original StarBlast it should focus okay, but it will be close. (When I was using my DSI I had about 1mm of in-focus left with the original StarBlast.) I'll check when I get a chance. I seriously doubt that either scope would work with the focal reducer. I tried the focal reducer earlier with my ETX-60 and it requires too much in-focus. My guess that it is best suited with SCTs and conventional refractors (where you can remove the star diagonal to get enough in-focus). Focal extenders should be okay, but the devil is in the details.


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#207 Live_Steam_Mad

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Posted 26 September 2016 - 08:34 PM

Can I ask about megapixels / image clarity on the R2 and others ? I think it was the Mallincam that was listed as a 1.5 MP camera. Is this standard / important? Or is this a variable directly related to cost?

 

Ed, How is the resolution on your R2?

 

Thanks!

All analog security type cameras such as the LN300 that I own (RJ11 DSP, ICX673 CCD) and my Mallincam Xtreme X2 / "MCX2" (ICX419AKL CCD) work at 1/4 resolution in the SENS-UP modes (i.e. when doing any long exposures).

 

For example, my MCX2 is 768 x 576 resolution in the exposures which range from 1/12,000 second down to 1/50 second (when Sens-Up is off), but when Sen-Up is used (range from x2 which is 50/2 = 1/25 second, to x128 (128/50 = about 2.6 seconds), and also when any arbitrary number of seconds of exposure is used (called Hyper Mode in the MCX2) then it takes a group of 4 pixels in a "square" and makes them into one big fat pixel. So the actual resolution when doing DSO's (Deep Sky Objects) is 384 x 288 resolution in PAL and 384 x 240 in NTSC ! which is 0.111 Mega Pixels at best!!

 

This becomes obvious when you test the camera using any cheap CCTV lens, simply enter any of the "x" numbers (SENS-UP) in any analog camera that I have used, and the nice detailed image of tree branches against the sky background suddenly quarters in resolution! You can see it happening! It happens in both my LN300 PAL and my MCX2 PAL. I believe it's the same for Xterminator, MCX, and all the other similar analog cameras, PAL or NTSC?

 

The plus side to this is that the sensitivity goes up by 4. So 1300mV sensitivity on the datasheet suddenly became 5200mV sensitivity! and the Xterminator's 3200mV Ex-View HAD CCDII sensitivity just became 12800mV sensitivity! Which is rather more than in many cameras with multi Mega Pixels, and with very low noise in the MCX2 etc.

 

Hope that wasn't too technical.

 

Regards,

 

Alistair G.


Edited by Live_Steam_Mad, 27 September 2016 - 02:33 PM.

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#208 jgraham

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Posted 30 September 2016 - 08:41 PM

After spending several nights becoming familiar with my new RI2 I blieve that I have found a set up settings that work well for general observing. At first I spent quite a bit of time working with the manual and fixed settings. This worked well for pushing the edge of what the RI2 can do, but I was constantly fiddling with the various settings. For general observing I found that the automatic settings worked very well. I still need to tweak some things a bit, but ths might work we ll for starters.

 

On the monitor I turned the brightness all the way down. The aspect ratio was set to 4:3. All other settings were left at their defaults.

 

On the image setup on the camera I set the brightness to 110, contrast 34. All other settings at their defaults.

 

For the exposure control I set the mode to Auto. Under the Auto settings I set the AE Level to 250 (max), AGC Max to 36, Sens Up to Auto.

 

I set the DNR to 6. For telescopes like the EXT I'd suggest a DNR of 3, higher if the tracking permits.

 

With these settings the images were nicely toned, easy on the eyes, and very natural looking. The next time I'm out I may boost the color saturation a bit, but it may not need it.

 

Using the automatic setting took all the work out of fiddling with the camera settings and I could spend the entire evening enjoying the view. The only problem I had was that I was seeing so much I filled pages of my notebook. It was fantastic to pick a region of the sky and explore every star and every object shown in the Pocket Sky Atlas.

 

Fun stuff.


Edited by jgraham, 01 October 2016 - 07:09 AM.

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#209 aeajr

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Posted 30 September 2016 - 10:58 PM

Thanks for the settings report.  That should be quite helpflu.



#210 aeajr

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Posted 04 October 2016 - 03:40 PM

Question about telescope options.

 

I have an ETX 80, F5 refractor  400 mm FL

 

I have an opportunity to pick up an ETX 90, F13.5 Mak.   1250 FL

 

Would they work equally well with the RI2?  

 

Using the FL reducer that would take the ETX 90 to F6.75.  Maks have a reputation for very sharp optics as compared to a short tube refractor and I believe the CA is reduced or eliminated.    I can polar align the ETX 90.  Can't do that with the 80.

 

Thoughts?

 

 

If you only had one to use with the RI2 kit, which would you use?


Edited by aeajr, 04 October 2016 - 03:41 PM.


#211 MarkMittlesteadt

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Posted 04 October 2016 - 03:47 PM

Question about telescope options.

 

I have an ETX 80, F5 refractor  400 mm FL

 

I have an opportunity to pick up an ETX 90, F13.5 Mak.   1250 FL

 

Would they work equally well with the RI2?  

 

Using the FL reducer that would take the ETX 90 to F6.75.  Maks have a reputation for very sharp optics as compared to a short tube refractor and I believe the CA is reduced or eliminated.    I can polar align the ETX 90.  Can't do that with the 80.

 

Thoughts?

 

 

If you only had one to use with the RI2 kit, which would you use?

Maks do have excellent optics. The ETX line might have had mount issues, but the optics are top notch. No CA with a Mak either. The reducer will help, but I can't speak to the speed for use with the R2.

Polar aligning will help. I assume it has a wedge with it? Because if it does you only need to track in RA being equatorial aligned instead of running in Alt-Az. 


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#212 Censustaker

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Posted 04 October 2016 - 05:40 PM

Question about telescope options.

 

I have an ETX 80, F5 refractor  400 mm FL

 

I have an opportunity to pick up an ETX 90, F13.5 Mak.   1250 FL

 

Would they work equally well with the RI2?  

 

Using the FL reducer that would take the ETX 90 to F6.75.  Maks have a reputation for very sharp optics as compared to a short tube refractor and I believe the CA is reduced or eliminated.    I can polar align the ETX 90.  Can't do that with the 80.

 

Thoughts?

 

 

If you only had one to use with the RI2 kit, which would you use?

 

For video: the faster option. 



#213 jgraham

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Posted 04 October 2016 - 11:24 PM

I have tried several times to image with an ETX-90 without success. It is optically very slow and while the tracking is adequate fir visual, it is not up to the task for imaging, even with the short exposures used for EAA. A focal reducer might work, but I doubt it. In theory you can mount the ETX-90 on a wedge, but I have had mixec luck with this. Some have excessive flex on the polar axis when mounted on a wedge.

 

My experience has been that the ETX Maks are fantastic visual scopes. EAA? Not so good. That said, Mike Weasner uses an RI2 on an ETX-105, so it might be worth a shot.



#214 aeajr

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Posted 05 October 2016 - 06:33 PM

I tried a new model ETX 90 today with the RI2 kit during the day.

  It was able to bring it to focus on a phone pole about 300 feet away and trees about 1/2 mile away.  When I added the focal reducer it did widen the view and reduce the mag.  So it will work with the ETX 90.

I did this during the day, not at night so I can't say how it will look with DSOs or planets.  But it seems to work.


Edited by aeajr, 05 October 2016 - 06:33 PM.

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#215 aeajr

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Posted 05 October 2016 - 11:02 PM

I don't recall if it was in this thread, but someone asked me to test the Revolution Imager R2 in my XT8i to see if it would work. 

 

Used without the focal reducer it worked fine.  Focus was around the real 1/3 as I recall.    I did an image impression comparison to my eyepieces.   I would estimate the image on the screen would be comparable to a 5 mm eyepiece of narrow AFOV.  Mybe comparable to a 40 degree AFOV 5 mm eyepiece.

 

But when I added the focal reducer I could not get the image in forcus.   I think it needed more inward travel.   When I brought it all the way out I then pulled the camera slowly out of the focuser to see if more back forcus would help, but it didn't.

 

The photo below is of the screen.  The dark region was not apparent as I looked at the screen so it is somehow an artifact of my camera phone.   This was a group of stars near and below Cassiopeia.  If it has a name, I don't know it.  I found it at random and used it for my testing.

 

 

Attached Thumbnails

  • RI2 image using XT8i, no FR (640x359) (2).jpg

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#216 jgraham

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Posted 06 October 2016 - 12:47 AM

Cool! That looks like the core of the brighter of the two clusters that make up the double cluster. It does show that you have a narrow field of view. One thing that I like about the RI2 is that it is a great match for a small telescope.


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#217 aeajr

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Posted 06 October 2016 - 08:16 AM

Cool! That looks like the core of the brighter of the two clusters that make up the double cluster. It does show that you have a narrow field of view. One thing that I like about the RI2 is that it is a great match for a small telescope.

John,

 

I just took a look using Stellarium and I believe you are correct.  That looks like the core of NGC 884.    I wasn't looking for anything specific, just found a starry area in my finder scope.   Didn't realize I was on the double cluster.  You must be good at Where's Waldo.  :D

 

Well, that emphasizes that my XT8i is not a good match to this device.   FL too long and the mag so high that I did not recognize where I was.  Too bad the focal reducer would not allow it to come into focus.  Also the lack of tracking meant I was constantly moving the scope and smearing the image.  

 

ETX 80, when I get the replacement, should be a much better match.


Edited by aeajr, 06 October 2016 - 10:40 AM.


#218 jgraham

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Posted 06 October 2016 - 11:34 AM

There might be a fun opportunity to use your RI2 with your XT8i... mount the camera on a small finder mounted on your scope. It shouldn't be hard to nearly match the field of view of your scope with the  RI2 finder. Comparing the fields could be very interesting. I did this many years ago mounting my Meade DSI along side my 8" f/6 scope. using a finder built from a lens scavenged from a 7x35 binocular.

 

A nice feature of this simple kit is that it is a lot of fun to experiment with.



#219 aeajr

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Posted 06 October 2016 - 11:39 AM

Interesting idea.   I have a 9X50 RACI on the XT8i but it does not take standard eyepieces.

http://www.telescope...c/49/p/7212.uts

 

 

Not sure if I could adapt a 1.25 star angle to it.


Edited by aeajr, 06 October 2016 - 11:55 AM.


#220 Robrj

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Posted 06 October 2016 - 12:22 PM

I did that with an Orion 50mm guidescope (non-helical focuser) and the ZWO ASI185MC camera.  I've used it as an electronic finder scope for my dob.

https://www.amazon.c...e/dp/B004SFUO9U

 

It makes a great little widefield scope too.

 

I put a parfocal ring on the 1.25" adapter of the camera so it sits about the same place every time I put it in the scope.

 

I get about a 2.5°x1.5° field of view.  With the RI (I'm assuming the chip dimensions are the same across both models), you'd get about 1.6°x 1°.

 

In an 8" dob, the equivalent field would be something like a 24mm 82° eyepiece (~1.6°) or a 14mm 82° (~1°).


Edited by Robrj, 06 October 2016 - 12:24 PM.


#221 jgraham

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Posted 07 October 2016 - 10:25 AM

Something like this...

 

Finder Camera.jpg

 

At one point I built two of these, after all the lenses did come of a binocular. :)

 

Twin Cameras-1.jpg

 

One was fitted with a color camera, the other with a monochrome camera. I still have these in storage. I might try one fitted with the RI2 just to see how well is works as a wide field EAA scope.

 

 


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#222 jgraham

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Posted 10 October 2016 - 12:22 PM

Speaking of non-technobabble...

 

I started a thread about using the RI2 remotely...

 

http://www.cloudynig...ady-for-winter/

 

...and one thing that I found immediately is how comfortable the little display that comes with the RI2 is to use indoors. Observing in a softly lit room rather than the in the dark outside is sooo nice. It also gives you a little more latitude in adjusting the screen making the colors so much nicer and more natural looking. I highly recommend setting up to observe from inside if that is an option. I already do this with my imaging gear and I'm going to do the same with my EAA kit. I like to bundle all of the cables so they are neat, orderly, and easy to set up and to put away reducing the fiddle-factor to the point where this is a comfortable way to set up to observe.

 

I had a great time last night star-hopping around Capricornus before ending the night visiting some of my favorites across Pegasus and up across Cepheus. I still want to get out with my ETX-80 to try out the automatic settings that I have been using with my StarBlast/LXD75.

 

Fun stuff.



#223 Newfie Stargazer

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Posted 20 October 2016 - 06:05 PM

Hope this thread is not dead.  I am interested in purchasing the Revolution Imager also, and like the OP I currently only own an Orion XT8 plus scope.  Seeing as he had limited success with it (narrow fov), what would be a fairly economical second scope to purchase for use with the R2 (budget of around $1500 USD).  Anyone know if the Celestron Advanced VX 6N would be decent?

 

Jim


Edited by Newfie Stargazer, 20 October 2016 - 06:07 PM.


#224 jgraham

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Posted 20 October 2016 - 07:53 PM

I was just thinking of the AVX with a 6" f/4 or f/5. That should be an excellent combination. Plan-B might be an Orion Sirius (EQ-5) with a short 6" on it. The Sirius should also handle something like an 8" f/4 Newtonian. which is an amazing scope for the RI2 and about as large as I'd go with this camera. I'm using an RI2 on an SN8 on an Atlas (EQ-6) and for me it is the ultimate EAA system.

 


Edited by jgraham, 20 October 2016 - 07:54 PM.


#225 Newfie Stargazer

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Posted 20 October 2016 - 08:16 PM

John,

 

Thanks for the reply.  The Celestron AVX 6N (f/5) would be perfect cost wise as I can currently get it bundled with the AVX mount for the same price as just the mount alone.  My only concern would be with back focus...




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