Portable EAA Setup

[festoon]

Just wanted to report on the great experience I have just had over the past week with my new set up. I am really new to video astronomy, and had not even thought about it until I saw the various threads on the Unistellar eVscope. Also this is my first write up of any of my equipment

I've previously had some good nights with my C8 on HEQ5 imaging planets using a QHY5L-II camera, but I found the faff of having to set up, making sure the laptop is charged, cold fingers, laptop battery running out. Sometimes by the time I had got through the whole set up, ready to go it took so long that the corrector plate had dewed over, or clouds had started to roll in.

In my back garden, using the C8 I have struggled to see any detail on galaxies and to be honest even struggled to see anything at all apart from a very faint occasional galaxy smudge. Good examples of this have been a long quest to get a good view of M81 and M82.

The aim of this set up was to put together a set up that I can have fully assembled, ready to go and to try and bring out detail that I just cant visually on deep sky objects from my back garden.

My first purchase was the revolution imager. This came up on astrobuysell a few weeks ago, and I'd read about it in discussions on CN as a way of getting into EAA for people of little experience of video astronomy. When I saw it up for sale I took the plunge. It came with the monitor, a x0.5 reducer, wifi add on, usb capture, and 25 foot extension cable (thank you Tim for sending it in such great packaging, and for all the help and information you gave me before buying). The plan in my head was that my conservatory would become my observatory. In the conservatory I can power the set up, have the live monitor on the dining table, and then using the extension cable have my set up in my usual observing location. In this set up the R2 can be powered by mains using the supplied AC-12V DC adaptor

Next I bought a second hand C5 from @Lockie. This was chosen primarily because of its weight and OTA length, but also giving a reasonable 5" aperture. I realise that at F/10 it is not suitable for EAA, but so far have worked at f/5 using the x0.5 reducer. The OTA was in great condition, and when I got it home I could not believe how lightweight it felt.

Finally I bought a AZ GTI mount from @FLO.  My plan was to couple it to a tripod from my AZ-EQ5. This is the 'old' AZEQ5 tripod type with the short legs and pier. I've never found this as stable as a standard HEQ5 tripod and spreader, but it is slightly lighter, and I thought would be a good match for the AZ GTI if I did not extend the legs (as I would not be viewing). When the AZ-GTI arrived I realised I forgot to buy the Berlebach 3/8" Photo Adapter...so again ordered this from @FLO and it arrived the next day!

Putting everything together, the whole thing I think is sub 10kg, and very easy to carry from the conservatory into the garden. For powering the mount I'm using a Tracer 12V LiPo 8Ah which I've "integrated" into the tripod

My first light was Friday night (18/5/18). It was a clear evening but to be honest this was not such a sucessful evening as after doing a north level 2 star alignment with the AZGTI, when I slewed to an object, sometimes I could find it, sometimes the OTA was pointing no where near where it was meant to be. However I did get a chance to to get use to the menus and settings of the R2 imager, and had some nice views of various globular clusters (when I could find them). After a couple of hours I found the corrector plate had dew'd over so brought the equipment indoors.

Looking at the mount I could see that the mount and Berlebach adaptor was not tightly coupled to the mount, so that when I move the mount in AZ the OTA was not moving correctly. After removing the adaptor and mount from the tripod, I tightened the Berlebach adaptor up to the mount. And upon final assembly of it all, it looked all OK.

Next evening Saturday (19/05/18) was also clear and I set up at dusk and did a quick north level 2 star align on Polaris and Arcturus. Using the goto I went straight for the globular clusters M92 and M13. It was still bright twilight, but I got a beautiful view and well within the FOV first time.  After viewing a few more globular clusters, I went onto galaxies. Great views of both M81 and M82. Then onto some galaxies that I've never even got got a sign of visually M51, M63, M94, NCG4565.

They all appeared first time in the FOV and tracking was working well to get for me great pictures. I was so impressed I snapped some pictures of what was on the monitor using my iphone. I know to some these will not be impressive, but I was so wowed to see these galaxies in such detail for the first time. These were with fixed exposure 128 FLD, DNR=6, ACG max=36, and after several minutes on screen. I know there are some star trails - but I expect if I used DNR=0 and used sharpcap to stack it would be significantly better.

Last night I connected up the USB frame grabber for the first time to the laptop and connected it to the R2. The PC recognised the USB driver straight away and sharpcap was easy to install, and recognised the camera. It was a cloudy night so I had nothing to look at, but just wanted a play on using the software. My only dissapointment was to find that I had a flicker on the image, almost horizontal lines that moved down in groups of 3 or 4. After a bit of googling I looked for the cause, and it was the fact that I had my laptop connected to the charger. As soon as I removed the mains power from the laptop and went onto battery the flicker went away. I then tried putting the laptop back onto the charger and it appeared again. I found I could also remove the effect if I stopped powering the R2 using the mains-DC plug and used a DC 12V battery instead. So it appears it is some sort of interference when both the R2 and laptop are powered by mains. This is a slight inconvenience as I will have to remember to take out the power cord to the laptop whenever I start stacking frames. Does anyone have any suggestions to have both the laptop and R2 powered by mains and for this problem not to occur?

My next plans are to get a f/3.3 reducer and a single filter slide.....

All in all, I am very much looking forwards to using the kit again. I have seen some galaxies that I never ever thought I would see from my back garden - with a 5" telescope, tiny goto mount, that I can carry easily, that takes 10 minutes to set up, even when its not completely dark outside! Bring on the holidays when the kids can stay up later and we can hopefully all enjoy seeing some new things in the sky

 

[Chris]

Great write up, Colin, wishing you even more fun ahead  

[festoon]

1 hour ago, Lockie said:

Great write up, Colin, wishing you even more fun ahead  

Thanks @Lockie. Absolutely love the C5 Best wishes to you!

[Chris]

1 hour ago, festoon said:

Thanks @Lockie. Absolutely love the C5 Best wishes to you!

I knew you would, enjoy  

[shirva]

Great stuff,, don't have an r2 myself but my buddy dragonman from Australia has done a lot with it,, he was a tester for the set up from mike at oc telescope,, 

I like the az gti on the big tripod ,, now that's the business,, 

Great report, ?

[RobertI]

Looks like you have the perfect portable EAA setup, very nice results, and they can only get better as you become familiar with the equipment. Looking forward to seeing more.  

[Howie_Oz]

Ditto to the comments above. And the kit you have chosen was wisely chosen for starting EAA. Your review and experience should be a sticky thread on SGL under the EAA / VA under "Example of how to correctly get started in EAA"! Great to see an excited new member of the "Observing-With-Camera" club, especially the shots of what you saw. Top write up.

[festoon]

Thank you @shirva, @RobertI, and @Howie_Oz I think its the first time in ages that I've had a real wow moment with astronomy. I was so excited I had to go and get my phone to take some photos. Its been a great first journey into video astronomy, I've learnt something new, and met/chatted with some top people along the way

I've literally 5 minutes ago just puchased a Meade f/3.3 focal reducer from @ngwillym (thank you Neil for responding to my wanted ad)....really looking forwards to getting that on the back and continuing my journey. Fingers crossed the aberations at f/3.3 will not kill the image

Once I'm happy with this, next step will be a filter slide...something like https://www.365astronomy.com/TS-Optics-Filter-Quick-Changer-incl.-1x-1.25-Filter-Drawer-Low-Profile.html

 

[RobertI]

I’ll be interested to see how you get on with the F3.3 reducer, I’ve never been able to get close to F3.3 without coma like effects, and have to settle for F4.0 -F4.5, although I have not really spent much time experimenting/fettling. I thought the reducer might be to blame as there are stories of dodgy manufacturing runs of F3.3 reducers, but I have tried three different reducers (including a Japanese version) and they are all the same. Others don’t seem to have such a problems and you may have more luck as I think you may have a smaller chip than my lodestar. Good luck and let us know how it goes. 

[shirva]

9 hours ago, festoon said:

Just wanted to report on the great experience I have just had over the past week with my new set up. I am really new to video astronomy, and had not even thought about it until I saw the various threads on the Unistellar eVscope. Also this is my first write up of any of my equipment

I've previously had some good nights with my C8 on HEQ5 imaging planets using a QHY5L-II camera, but I found the faff of having to set up, making sure the laptop is charged, cold fingers, laptop battery running out. Sometimes by the time I had got through the whole set up, ready to go it took so long that the corrector plate had dewed over, or clouds had started to roll in.

In my back garden, using the C8 I have struggled to see any detail on galaxies and to be honest even struggled to see anything at all apart from a very faint occasional galaxy smudge. Good examples of this have been a long quest to get a good view of M81 and M82.

The aim of this set up was to put together a set up that I can have fully assembled, ready to go and to try and bring out detail that I just cant visually on deep sky objects from my back garden.

My first purchase was the revolution imager. This came up on astrobuysell a few weeks ago, and I'd read about it in discussions on CN as a way of getting into EAA for people of little experience of video astronomy. When I saw it up for sale I took the plunge. It came with the monitor, a x0.5 reducer, wifi add on, usb capture, and 25 foot extension cable (thank you Tim for sending it in such great packaging, and for all the help and information you gave me before buying). The plan in my head was that my conservatory would become my observatory. In the conservatory I can power the set up, have the live monitor on the dining table, and then using the extension cable have my set up in my usual observing location. In this set up the R2 can be powered by mains using the supplied AC-12V DC adaptor

Next I bought a second hand C5 from @Lockie. This was chosen primarily because of its weight and OTA length, but also giving a reasonable 5" aperture. I realise that at F/10 it is not suitable for EAA, but so far have worked at f/5 using the x0.5 reducer. The OTA was in great condition, and when I got it home I could not believe how lightweight it felt.

Finally I bought a AZ GTI mount from @FLO.  My plan was to couple it to a tripod from my AZ-EQ5. This is the 'old' AZEQ5 tripod type with the short legs and pier. I've never found this as stable as a standard HEQ5 tripod and spreader, but it is slightly lighter, and I thought would be a good match for the AZ GTI if I did not extend the legs (as I would not be viewing). When the AZ-GTI arrived I realised I forgot to buy the Berlebach 3/8" Photo Adapter...so again ordered this from @FLO and it arrived the next day!

Putting everything together, the whole thing I think is sub 10kg, and very easy to carry from the conservatory into the garden. For powering the mount I'm using a Tracer 12V LiPo 8Ah which I've "integrated" into the tripod

My first light was Friday night (18/5/18). It was a clear evening but to be honest this was not such a sucessful evening as after doing a north level 2 star alignment with the AZGTI, when I slewed to an object, sometimes I could find it, sometimes the OTA was pointing no where near where it was meant to be. However I did get a chance to to get use to the menus and settings of the R2 imager, and had some nice views of various globular clusters (when I could find them). After a couple of hours I found the corrector plate had dew'd over so brought the equipment indoors.

Looking at the mount I could see that the mount and Berlebach adaptor was not tightly coupled to the mount, so that when I move the mount in AZ the OTA was not moving correctly. After removing the adaptor and mount from the tripod, I tightened the Berlebach adaptor up to the mount. And upon final assembly of it all, it looked all OK.

Next evening Saturday (19/05/18) was also clear and I set up at dusk and did a quick north level 2 star align on Polaris and Arcturus. Using the goto I went straight for the globular clusters M92 and M13. It was still bright twilight, but I got a beautiful view and well within the FOV first time.  After viewing a few more globular clusters, I went onto galaxies. Great views of both M81 and M82. Then onto some galaxies that I've never even got got a sign of visually M51, M63, M94, NCG4565.

They all appeared first time in the FOV and tracking was working well to get for me great pictures. I was so impressed I snapped some pictures of what was on the monitor using my iphone. I know to some these will not be impressive, but I was so wowed to see these galaxies in such detail for the first time. These were with fixed exposure 128 FLD, DNR=6, ACG max=36, and after several minutes on screen. I know there are some star trails - but I expect if I used DNR=0 and used sharpcap to stack it would be significantly better.

Last night I connected up the USB frame grabber for the first time to the laptop and connected it to the R2. The PC recognised the USB driver straight away and sharpcap was easy to install, and recognised the camera. It was a cloudy night so I had nothing to look at, but just wanted a play on using the software. My only dissapointment was to find that I had a flicker on the image, almost horizontal lines that moved down in groups of 3 or 4. After a bit of googling I looked for the cause, and it was the fact that I had my laptop connected to the charger. As soon as I removed the mains power from the laptop and went onto battery the flicker went away. I then tried putting the laptop back onto the charger and it appeared again. I found I could also remove the effect if I stopped powering the R2 using the mains-DC plug and used a DC 12V battery instead. So it appears it is some sort of interference when both the R2 and laptop are powered by mains. This is a slight inconvenience as I will have to remember to take out the power cord to the laptop whenever I start stacking frames. Does anyone have any suggestions to have both the laptop and R2 powered by mains and for this problem not to occur?

My next plans are to get a f/3.3 reducer and a single filter slide.....

All in all, I am very much looking forwards to using the kit again. I have seen some galaxies that I never ever thought I would see from my back garden - with a 5" telescope, tiny goto mount, that I can carry easily, that takes 10 minutes to set up, even when its not completely dark outside! Bring on the holidays when the kids can stay up later and we can hopefully all enjoy seeing some new things in the sky

 

Got a more detailed read at your post now I'm home from work,

The phase lines are a common thing using some of the power supplies,, few years back I had the same problem with my Phil dyer camera , ended up as you found out,,to be the power adapter,,

I bought my mains to dc adapter from maplins ( RIP) and all power related issues were solved,, at the time this was what flo were selling as well,

Flo have a nice one that will solve your problem , nice regulated unit,, actually nicer than mine lol.

https://www.firstlightoptics.com/power-accessories/nevada-ps-08-6a-8a-regulated-linear-power-supply.html

Davy

[festoon]

Thanks Davy @shirva :) I will look into buying one of those to power the camera

[shirva]

Another thing you could add to your set up Is a a three way Av splitter ,this would allow you to leave your monitor up at the scope for doing adjustments ect and then run your split feed down to your video grabber and into computer,,

[Howie_Oz]

19 hours ago, festoon said:

I've literally 5 minutes ago just puchased a Meade f/3.3 focal reducer from @ngwillym (thank you Neil for responding to my wanted ad)....really looking forwards to getting that on the back and continuing my journey. Fingers crossed the aberations at f/3.3 will not kill the image

Once I'm happy with this, next step will be a filter slide...something like https://www.365astronomy.com/TS-Optics-Filter-Quick-Changer-incl.-1x-1.25-Filter-Drawer-Low-Profile.html

 

Ooooo .... aberations ... you may get vignetting with such big reduction and a mid sized sensor in the Infinity. But get out and try it out. You did good in getting 2nd hand (and those 0.3x SCT reducers are scarce as)! 

Do hope I didn't confuse you there? Bottom line ... crack on with the Infinity and 0.33x test. Crop off the vignette if you have to and see if it works for your needs. If not, resale should not loose you money. If you decide to keep the 0.33x anyway for future use ... it'll work nice with smaller sensor cams of around 5 to 6mm diagonals.

 

Don't read the rest of this post ..... Unless you'd like to know why diff sensors may or may not vignette with reduction. It's not a physics explanation with precise correct terms etc, but it's how I think of it in an easy to remember way.

 

When light is focused by lens or mirrors, it forms a cone of light. Light intensity/brightness is brighter in the middle of the cone of light, and falls off at the edges of the cone. Hence a small sensor does not extend much into the edges of the poorer brightness of the cone. So they suffer much less from vignetting (dark corners and edges). Larger sensors extend much more into the less bright edges of the cone of light, and so suffer much more from vignetting. The larger the sensor diagonal the more it suffers from vignetting.

Second handy thing to know, is reducers act by steepening the angles of the edges of the light cone (so they "reduce" the focal length of the scope). It is this steepening of the light which stretches the stars into elongated rather than round (IE coma). The middle parts of the light cone are still relatively unsteepened as the light right through the middle would clearly be still parallel coming straight down the middle of the scope, even though the edges are now more steep and stretched in order to reach focus shorter than without the reducer. So once again, small sensors will sit more in the region which is less stretched and are less likely to get coma. ANd I'm sure you can then work out why the larger the sensor the more it gets coma around the edges.

And third thing to know, Is because reducers (effectively) shorten the focal length of your scope, it means the point you reach focus moves further and further into the scope as you add more and more reduction. So to work with reducers, your scope needs lots of focuser "in-travel". Refractors and SCT's have much more in-travel so usually (not always, but usually) will have enough travel into the scope to bring the camera to focus. However, if you ever think about getting a Newtonian telescope, they do not have much in-travel in the focuser and often cannot bring a camera to focus when you use reducers. People desperate to use reducers with Newts often resort to shortening the tube with hacksaw, or replace the primary mirror bolts with longer ones so the mirror is moved into the tube, or shorten the struts (if its a truss newt - and its what I've done to mine).

[festoon]

Thanks @Howie_Oz my sensor is is a revolution R2, so I believe only 1/3 inch in size. So hopefully vignetting will be small.

 

[festoon]

Is it possible to ask for some help on these images I've taken...I was using the x0.5 reducer that came with the R2 imager (so I would have expected f/5 from the C5), but just comparing them to what I'd expect they look more like f/3.5. Is someone able to please give an opinion on what focal reduction is being achieved here with the C5?

[cuivenion]

4 minutes ago, festoon said:

Is it possible to ask for some help on these images I've taken...I was using the x0.5 reducer that came with the R2 imager, but just comparing them to what I'd expect they look more like f/3.5. Is someone able to please give an opinion on what focal reduction is being achieved here with the C5?

Hi, the actual reduction you'll get depends on how close the reducer is to the sensor. If it's not giving as much reduction as you hoped you need to move it nearer to the sensor.

[festoon]

Hi @cuivenion, thanks for your answer  You are absolutely right....The reason I asked this is that the R2 imager has a fixed position 0.5x reducer (with the lens about 50mm from the ccd chip). If I am right I am achieving too much reduction,so would need to move the lens further from the ccd....but I would have thought the manufacturer would have chosen the spacing to achieve the stated x0.5.

[cuivenion]

1 minute ago, festoon said:

Hi @cuivenion, thanks for your answer  You are absolutely right....The reason I asked this is that the R2 imager has a fixed position 0.5x reducer (with the lens about 50mm from the ccd chip). If I am right I am achieving too much reduction,so would need to move the lens closer to the ccd....but I would have thought the manufacturer would have chosen the spacing to achieve the stated x0.5.

Ah if it's a particular spacing given by the company I'm not sure then, but in general the nearer the reducer is to the sensor the more reduction you get.

[RobertI]

5 hours ago, festoon said:

Is it possible to ask for some help on these images I've taken...I was using the x0.5 reducer that came with the R2 imager (so I would have expected f/5 from the C5), but just comparing them to what I'd expect they look more like f/3.5. Is someone able to please give an opinion on what focal reduction is being achieved here with the C5?

May be teaching you to suck eggs here, but the way I work out the reduction is to put the image through astronomy.net or similar astrometry tool. The tool should tell you the field of view of the image. You can use then use a FOV calculator such as astronomy tools to find out what focal length with your sensor gives that field of view. The reduction is then calculated as reduced focal length divided by native focal length. I tried to do this for you but (a) I couldnt get your image to solve on astrometry.net, possibly because of the coma and (b) I couldn't find out the size of the sensor!

[festoon]

Hi @RobertI, thank you for your answer  You have come across the same problems as me...I tried astometry.net but the images failed, I guess because of the fact the pictures were not 'square' to the screen.

Also finding the specs of the R2 chip seem very difficult..This I found on CN

Size  1/3"

976 (H) × 582 (V) active pixels (1020 (H) × 596 (V) total number of pixels)

5.0 µm (H) × 6.25 µm (V) pixel size

I dont know if you use the total pixels or active pixels