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easy EAA with visual equivalent setup

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#1 vtornado

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Posted 03 December 2019 - 03:35 PM

Hello, excuse dumb questions that have already been asked.

 

First of all I generally don't want to deal with technology while observing.  Me and the telescope on a quiet, dark night

is a respite from the frazzled world I live in.  However …

 

I have a son who cannot view through my telescope. and I would like to show him what I look at.

So I would like a setup where I can record more or less what I see at the eyepiece so I can

bring it in and show him.

 

Features and I realize that the ideal system may not exist.

1) I already have an android tablet running at my scope to run sky safari, if the camera plugged into that it would be great,

and be able to store the images on that.  Having to bring out a lap top could kill the project, as I don't have a spare laptop.

 

2) I don't need much enhancement, no long exposure photon collection, no super high res, something that more or less matches my eye. 

 

3) If possible I don't want tracking.  I do have a CG4 mount with RA drive I could use.

 

4) I am only going for the bright stuff, plieades, orion neb, double cluster, andromeda …

 

5) cost, I would like to keep it down sub $200?? And I am willing to purchase used.

 

I've tried sketching but I stink at it.

 

Is afocal with a point and shoot camera sufficient??  I don't have a cell phone.


Edited by vtornado, 03 December 2019 - 04:32 PM.


#2 GaryShaw

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Posted 03 December 2019 - 04:12 PM

Hi - well, using only an eyepiece, there's not a way I know of that you can show him exactly what you see. A close second might be rigging your Android up with the lens set to be able to see and photo image in the eyepiece. I know of a lot of rigs that will do that for an iPhone or Android phone but I'm not sure about the tablet - likely not. Even then, he'd have to be there viewing the screen or you'd have to snap a pic and show him latter. Not sure how it would work - alternating your own visual viewing with attaching the android rig in place to snap a picture.

 

As you know, those of us in the EAA forum are using a camera in place of an eyepiece which allows us as well as others to see what what the camera sees - live. The camera gets so much more than a human eye can that it opens up a door to really seeing what's out there - especially in light polluted locations. Its very compelling but, well, you want to avoid tech at the scope. Personally for me the tech makes it all possible and I totally enjoy sitting outside under the sky, listening to quiet music while watching galaxies, nebulae, etc appear comfortably before my eyes on my laptop...but it's a scope, camera and laptop event. Others will likely have other ideas to help you out.

Gary


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#3 vtornado

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Posted 03 December 2019 - 04:46 PM

Thanks for your help, 

 

The pic does not have to be through an eyepiece, just sort of resemble that.

I was hoping that the long exposure  and stacking to get a superior image,

could be cut down to a single image, that is approximately what my eye sees.

My impression is that any astro camera is much more sensitive than my eye.

 

There is the 500 rule, which says  I can take a three second shot at 1500mm with minimal trailing, I assume that is

no eyepiece on an full frame DSLR. (30x)

How does this equation change with an astro camera with a small sensor?

I assume the exposure would have to be faster to avoid trailing.

 

Are there any astro cameras that plug into a android tablet?



#4 Noah4x4

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Posted 03 December 2019 - 05:59 PM

When persuing visual astronomy most DSOs look like a faint fuzzy blob. If that is what you want to show your son (e.g. "what you can see"), then I guess most decent CMOS cameras (such as DSLRs) in a longish exposure mode might be able replicate that. But your limit will be 20 second exposures before field rotation and star trails kick in. Also your field of view might be very narrow.

 

However, it won't be too exciting to see what a best looks like a smudge on the lens. Planets and lunar are inevitably a tad easier.  The reason we invest in expensive gear for EAA is a desire to enjoy a better view than via visual. There isn't any magic cheap solution. However, a second hand DSLR body can be picked up for under £100/$100.


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#5 vtornado

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Posted 03 December 2019 - 06:22 PM

Thanks for the input, 

 

That is why I said the bright objects, I am not going to show him wisps of grey.,

If I want to show him those things I would just down load the images  from someone else.

 

My intent is to show him the high lights of what I see at the eyepiece.  Things like oriion neb, Pleiades, etc.

That will make him understand why I do what I do, and it is something we can share.



#6 1983cowboy

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Posted 03 December 2019 - 08:09 PM

I wonder if it might be worth experimenting with AstroToaster (http://www.astrotoaster.com/download) to see if it's what you're looking for. It’s freeware that uses the Deep Sky Stacker (also free) processing engine and gets close to an EAA experience using a DSLR and laptop. It’s not quite real time, but it’s kinda close – and there’s no post-processing unless you want to do some later with the pics you save. It’s good to have your telescope driven in RA, but the exposures are short and there’s no autoguiding needed.

 

An astrophotographer named Carl Smith has some cool videos (including a nice tutorial) about using AstroToaster on YouTube: https://youtu.be/uG9ByXFDrEE

I’ve dabbled with it now and again at home. It’s pretty fun!

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#7 vtornado

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Posted 04 December 2019 - 08:34 AM

Thanks, looking into astro-toaster



#8 S.Boerner

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Posted 04 December 2019 - 09:49 AM

You asked "Are there any astro cameras that plug into a android tablet?"

 

Good news, bad news...

 

I've used my ASI385mc connected to my Nexus 7 Android tablet with a $5 OTG cable.  That leads me to believe that a ASI120MC-S color ($150) would work too.  ZWO has an app called ASICAP that even lets you zoom, scroll, etc. around the screen and exposure times longer than 10 minutes.  The camera comes with a 1.25" nosepiece that would let you connect it to a 1.25" focuser.  Similar USB2 or USB3 cameras are available from other manufacturers.  That's the good news. 

 

The bad news is that the camera has to draw power from the tablet while at the same time providing the signal.  As far as I've been able to determine it is impossible with my tablet to use an external power source at the same time so the tablet's battery drains in about an hour.   Obviously, using a laptop gets around that problem and provides much better software possibilities (Sharpcap, FireCap, etc.).

 

The other concern is that while you can switch eyepieces on a scope, you're pretty much locked into the sensor size of your camera unless you want to fiddle with a focal reducer.  You get a FOV similar to an eyepiece with a focal length of your sensor's diagonal size.  That ASI120MC-S has a 1/3" sensor or about 8mm.  That means that unless you pick the right combination of OTA and camera you may not be able to see much of larger targets.   Your 80mm F5 might work pretty well with a ASI120MC-S.  You'll find that cameras with larger sensors are much more expensive so that's why I mention the 1/3" sensor camera. 


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#9 Eddgie

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Posted 04 December 2019 - 09:59 AM

Not on your budget and not within your constraints.

 

My advice would be to accept the fact that you are going to need a little more technology and raise the budget and go to a Revolution 2 imager.

 

This is a pretty amazing setup..  Everything you need is in the box.

 

The really great news is that you will not be limited to just bright showcase objects.  You can get some pretty faint DSOs with the Rev 2.  The resolution is not very high, but your kid will get to share the joy of seeing what you can see.

 

https://www.revoluti...com/products/r2

 

At $299, it is still a reasonable price, and you get everything you need to allow you to share the view of what the telescope is pointing atIsn't that the most important thing?

 

Freaking amazing what you can do for $299:

 

https://www.revoluti...ee-for-yourself


Edited by Eddgie, 04 December 2019 - 10:06 AM.

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#10 Starman27

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Posted 04 December 2019 - 02:33 PM

Four of us in our astronomy club have Revolution imagers. They are big hits at public star parties. It is amazing what you can get for $299.



#11 rave3c0

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Posted 05 December 2019 - 02:28 AM

Hello,
I have a couple suggestions based on your needs and my limited experience.  However, they may involve more tech than you seem comfortable with.  but they can be found cheaper used smile.gif  

Revolution Imager 2:
https://youtu.be/p134KP4GMGY
https://youtu.be/WNjiOCKO-b8

 

As others have suggested and for good reason... IT just works and its fun.

PROS:

- NO laptop required
- Self contained

- Fairly easy to use

- Can control with supplied cabled remote or buttons on back of camera 

- Has its own mini monitor

- Fits standard 1.25 connections

- Budget, can find great deals used for your budget

 

 

CONS:

- NO tablet / smartphone connectivity (That I know of) 

- TONS of cables: remote, power, monitor, battery pack

- small FOV, tho mitigated with focal reducers (includes a 0.5x)

- Remote viewing may requires more cables and power

- For image capture and saving, needs laptop and USB frame grabber device (more cables) OR the mini DVR

 

 

ZWO ASI 224MC or 120 or similar small ZWO COLOR cam

AND an ASI AIR

https://youtu.be/TwDoKpvajoo

 

This may seem to be hugely complicated, but you wouldn't need to learn or use half the features available in the ASI AIR, nor as much gear as AstroBackyard (Trevor) has in his vid but its a great demo of the setup and use and expands your capability and "share-ability".  ASI AIR is made for wireless use with Tablets and smartphones, but also only works ZWO cams.

 

PROS:

- ASI AIR is Purpose built for Android tabs and phones

- WIFI - home network or direct from tab to AIR

- More camera capability for the money. More sensitive, better resolution, 

- Budget,  Ive seen zwo cams and AIR combos on the classifieds go for 200 - 400 depending on the cam.

- LESS cabling,  Data out and power in over 1 cable for the cam to AIR, then only 1 power cable to the AIR

- One more cable to a goto mount gets you mount control over wifi from tablet

- More room to grow if you get hooked on EAA wink.gif

 

CONS:

- Tailored more for AP than video astronomy or eaa, more features than may be needed for simpler use.

- More of a learning curve, but nowhere near as complicated as astrophotography. IMHO, what you would have to learn with the R2 overlaps anyway with a ZWO camera setup. For instance exposure times, gain, brightness, basically any setting inherent to any camera

- Also has a small FOV without focal reducers.

- Could be more of a tech headache , you'll be adding computer and software to the equation

- Budget, depending on used market can be more expensive

 

For a final thought on both of these setups, you'll be amazed either way at what you can get in one image with just a couple seconds of exposure or even 1 sec.

 

I get the feeling you may be looking more for portable viewing.  I think these two systems have big differences there to consider. With the R2 you may have easier setup but less portable viewing since you have to be at the scope to see the monitor which is only somewhat portable to near by.  With the zwo cam and air you may (depending on tech comfort) have a longer or more frustrating setup, but your portable viewing is easier and higher res on the tablet.

 

Regardless of which route you go if you don't like it, reselling either of these setups would be easy. I rarely see either sit too long in the classifieds.

 

But beware! One or the other may get you hooked and you may end up with both setups in which case you would have a very well-rounded EAA capability.

 

Maybe more info would help.

What cameras do you already own? (might help with afocal advice, but im not experienced there at all)

Any other viewing constraints?


Edited by rave3c0, 05 December 2019 - 03:06 AM.

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#12 vtornado

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Posted 06 December 2019 - 06:42 PM

I have a canon rebel dslr, and a canon elph.  I do have one of those clamps to hold a small camera to the

eyepiece for afocal, and I have a dslr to 1.25 tee adapter to connect the telescope to the dslr.

 

Since I am going for bright objects first I am considering just using the dslr and the needed barlows to get the

image scale correct, I have a 2x and 3x barlow.

 

If the revolution could save images without a lap top it would be a winner.  It would be nice to be able

to just save what is on the screen to a flash drive, or secure digital card.  Maybe I just photograph

the revolution screen and bring it in?   Too dim?? Glare ??? 

 

My son cannot go outside to the telescope.  I need to be able to bring the image in to him.

 

I may be able to put the scope close enough to the house so a device can see my wifi network.

Maybe the ASI AIR might work.



#13 Steve C.

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Posted 06 December 2019 - 07:10 PM

Revolution does sell a mini dvr for recording images, or you could use a splitter for the video feed and put it to a recorder that takes the rca video cable.



#14 Noah4x4

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Posted 07 December 2019 - 03:01 AM

I originally used  a second hand DSLR body with internal screen that I affixed to my OTA with a (cheap) T-adapter. I could either view on the camera's screen or save to later view on a laptop. A DSLR will offer greater quality than a Revolution Imager for similar price.

 

The problem that then arises is that if photographing at a typical OTA's f/10 the FOV is narrow and the required length of exposure means field rotation can be an issue. We then buy a £120 focal reducer and fall further into the expensive rabbit hole of this hobby. Buying a cheap planetary camera such as a Nexstar Burst is great until you want to photograph DSOs.

 

The Revolution Imager is arguably best option if that is the limit of yoir budget. But if not satisfied after a few months, once again, you fall into the expensive rabbit hole. If pursuing quality, there are no cheap solutions. 




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