Coming Back And Wanting EEV

[Toadeh]

Hi All,

I'm back after a few years out  Anyway, when I first started all this back in 2009/10 I always wanted to stream the live images to a screen so I can involve more people but costs and technology was prohibitive back then (or so I though). So, now I'm back with a child and want to show her some things in the sky.

I've dug out my old gear and it still works which is:

- Skywatcher 150p
- Goto Mount (It's an EQ5 as I retro fitted the goto to it back in about 2013)

From what I understand, I could get a ZWO ASI290 and use that on the scope? Ideally I want to do colour and I'm only focusing on bright objects in the sky for now but it would be good to be able to do some nebula and galaxy work on it. However, to start with and to show my daughter, I guess planets are a good place to start.

I intend to connect it to my macbook pro (it's an i9 2.9 with 32GB RAM). But, do I need anything else which would be better for the scope/camera? Do I need to do anything with the focal length and if so, what

I'm well aware that what I buy now, probably won't see next Jan without being upgraded but I'd rather not get a dud to start off with.

So, questions:

- Would the ASI290 be a decent start? If not, what?
- Do I need an additional focal changes? Again, what is best and where from?
- What software is recommended/people used for a Mac?

Any advise is much appreciated.

[tteedd]

Hi Toadeh

I too have been dormant for some time (I do wander out to my observatory when the moon is not around). I went the normal route for someone that does not want to be an astro-photographer but wants to see more (increase in aperture - cheap video camera - loss of interest).

However I have recently been looking at cameras Like the ZWO AS1294 MC and feel that something like this may be my route to more enjoyable quasi real-time astronomy in our light polluted environment.

But this would cost me more dough than my rig and about the same as my second hand observatory.

I need more information or interaction with others, that I do not get now the astro clubs are virtual.

So I am hoping you get some great replies!

[Martin Meredith]

For lack of replies I'll make a few comments although I have no experience with the ZWO cameras mentioned.

The key things to aim for for EEVA-style observing are sensitive cameras and fast focal ratios (under f6, preferably under f5). Both help to get bright images on to the screen quickly, ie in the near-live timescale (say 5-15s for the initial image, then subsequently improving as more are stacked). Sensors with quite large pixels and high quantum efficiency (75% or above) work well, or cameras with smaller pixels that can be used in binned mode (to effectively create larger pixels). Many users of SCTs employ focal reduction. Newt users seems to have success with native focal ratios so long as they are f5 or under.

It is worth visiting https://astronomy.tools to check not only the apparent field of view of your scope and proposed camera combination (with or without focal reducers), but also  the CCD suitability calculator at the same site, to determine whether you will be over or under sampling. I operate at just over 2"/pixel which is under sampled on the nights of best seeing, but I find it adequate most of the time.

You also need to decide whether you want a single setup for 'everything' ie all the way from large bright nebulae to planets, or whether you'd be happy with a compromise that works well for most objects. It is actually quite hard to find a setup that is good for large bright nebulae and planets since they are at opposite ends of the apparent diameter scale.  I myself find there is plenty of mileage in smaller sensors and continue to use a 0.4 Mpixel camera with large pixels as my only camera, paired with a fast Newt (8" f4). This is a compromise in the sense that it isn't good for the bright planets (though it is good for Uranus, Neptune and Pluto and their respective moons), and it isn't good for larger objects like many bright nebulae (they don't fit). But it works well for the remaining 99.9% of DSOs... 

Colour cameras are good for the immediate wow factor for bright objects but are actually a little harder to use than mono cameras in an EEVA-setting (more controls to get the colour balance right). Mono cameras provide better spatial detail of galaxies and other faint objects in near-live viewing. It comes down to what kind of objects you envisage spending most time looking at. There is no question that open clusters and planetary nebulae benefit from colour, as do globular clusters and bright/reflection nebulae. As you look at the kind of images that have been posted on EEVA forums, it is worth checking how many are colour images of fainter objects -- not so many. You'll see a lot of M27, M57, M8, M4 and the like, but these are really pretty bright. Its something that is worth bearing in mind in near-live viewing. That said, most open clusters (of which we see very few on the forums) respond well to colour.

Toadeh, I'm a Mac user and can say that EEVA software for Mac is very limited -- but does exist. I believe ASIlive works on Macs for instance if you end up with a ZWO camera. StarlightLive works on Macs for certain Starlight Xpress cameras such as the Lodestar and Ultrastar but isn't being maintained as much as a few years back (I've had problems running it on the latest OSX, Catalina). Mainly for this reason I've written software that works on a Mac (Jocular) but that doesn't support OSC cameras (it does support mono + filters for colour though) nor cameras with large pixel counts. So the situation on Macs is not ideal, but it is workable, though there may only be one option for any given camera that actually works!

Tteedd, you don't say what your scope and mount are so it is a little hard to comment in more detail on your proposed choice of camera. 

cheers

Martin

[stash_old]

And if you have deep pockets - one of these https://scitechdaily.com/worlds-largest-digital-camera-snaps-first-3200-megapixel-images-will-explore-cosmic-mysteries/   😈

[R26 oldtimer]

The 290 would make a difference compared to the 224, if you are going for mono. If not get the 224 cheaper, and save for a 294. Of course, there is the lodestarx2c which is still a very nice and sensitive option.

[callump]

Hi Toedeh,

I started with an ASI290MM mini camera for EEVA as it was what I had (i'd bought it for guiding).

Here is a pic I took with it of M82 - this was my first go at EEVA so did not know what I was doing at all!

The tech details are:

Celestron C11 with F6.3 reducer
Losmandy G11 mount
ZWO ASI 290MM Mini camera
Indigosky Raspberry Pi
Cloudmakers Astroimager and Astrotelescope
Processing using Jocular
Stack of 10 sub-exposures of 10s

The ASI290 has quite small pixels - 2.9 microns - and the chip is quite small, so after much deliberation & dithering  and in the end not really being able to decide, i plumped for an ASI174MM mini. Which has bigger 5.8 micron pixels and a bigger chip (so able to get a wider field).

Here is a pic of NGC 891 I took recently with the ASI174. 

M82 is about 9 arc-minutes long, and NGC 891 is about 13 arc-minutes long. I have cropped the NGC 891 image square to be about 14 x 14 arc mins in size, as I am currently getting awful edge effects.

I'm not sure it will help your decision process really - it is worth trying out field calculators to see how big a field you will get with whatever scope and camera combinations you like, and what sort of objects you are interested in observing. Also to some extent it will depend on how much you want to pay for the camera.

Callum

 

[tteedd]

Thanks Martin

I have a Skywatcher 10" Goto Flextube Dobsonian. f 4.7 (I also have a 5" Dob f 5 on an equatorial mount that I bought cheap to experiment with equatorial mounts).

The 10" is mounted permanently in my observatory. I bought it second hand originally for the aperture, not the portability.

But once I have the camera, if there is a rush of enthusiasm caused by the new kit I might change the scope. Something to bear in mind as I make my choice.

The Dyas video camera was great for bright objects but little else and ended up with a telephoto lens on it that I picked up cheap. It was a good super-finder! Proving to me that I was indeed pointing the Dob in the right direction.

I still think that I don't have the patience for astro photography and playing around with lots of processing and colour filters.

The ZWO AS1294 MC seems to fit the bill but is a lot of dough (about £1000) and I was hoping to attract comment from people with this or with similar and perhaps cheaper colour cameras and the necessary software and experience to help me not to make an expensive mistake or give me a feeling I'm going in the right direction. I think I need the sensitivity and cooling but am ready to be persuaded especially if there is a lower cost option.

I have just taken my observatory HP laptop in to have the overheating sorted (a three year old problem) so something must be stirring in my desire to make better use of my observatory!

Ted

 

[Martin Meredith]

Hi Ted

A 10" f4.7 would be a great scope for EAA in my opinion, paired with the right sensor, so long as your tracking is up to it at that focal length. The ASI 294 looks like an excellent fit but looking at the arcsec/pixel I imagine you'd mainly be using it binned 2x2 except on nights of great seeing. Everything else looks significantly smaller in terms of FOV. I quite like the newish 533 with the square sensor which isn't too bad FOV-wise, but I've no idea how it compares cost-wise.

Martin

[tteedd]

Hi Martin

You have me looking at the 533 now.

Of course my rig, from a traditional astro photograpy viewpoint, does not have adequate tracking. But I am coming at this from a video-viewpoint as I believe that current software allows this. If I did want v good pics I would need the software to allow me to correlate and stack lots of short sequences. It is the software aspects as well as the physical attributes that I was hoping for some guidance on.

Cost wise the 533 appears well over £100 cheaper and is said to not have the amp glow which is apparent from the 294. This may be a significant advantage for my application.

Although the local astro club is not live at the moment I have just been put in touch with an astro photography member who uses the 294. I hope he can give me the benefit of his experience. But I still hope someone reading this is using the 294 (or 533) in a quasi video mode than I envisage and can give me the low down on software.

At least all this is reviving my interest in getting out and observing!

Ted

[Deflavio]

On 22/09/2020 at 11:56, Toadeh said:

 

I've dug out my old gear and it still works which is:

- Skywatcher 150p
- Goto Mount (It's an EQ5 as I retro fitted the goto to it back in about 2013)

From what I understand, I could get a ZWO ASI290 and use that on the scope? Ideally I want to do colour and I'm only focusing on bright objects in the sky for now but it would be good to be able to do some nebula and galaxy work on it.

Hi Toadeh,

If you are looking for a cheaper but still a good option considering your equipment, I would also suggest the classic ASI224MC for about £220. It's not the latest camera but it is very sensitive colour camera and it has been one of the most used for EAA so you will find a lot of info and examples online.

The 244 has a smaller field of view compared to 533 or 294 but considering your 150p with a focal length of 750mm you will get a good 1.05''/pixel resolution and a "nice frame" of 0.4x0.3 degrees zooming on most of the major bright objects. I'm thinking myself to get the 150 as "ideal" EAA travel scope.   

The 533 and 294 on a focal length of 750mm will probably be better for large objects or wide nebulas. Of course, you can image wide and crop later and since 533 and 224 have the same pixel size you will get the same final resolution per pixel. The 294 slighter bigger pixels with a resolution of 1.2''/pixel which is almost the same. Just to give you an idea using https://astronomy.tools  as suggested above:

With longer focal lengths, like the 10' f4.7 from @tteedd  the 533 and 294 would probably better because the field of view is getting smaller and smaller and closer to the 244 on the 150p. 

 

Flavio

Edited September 24, 2020 by Deflavio

[Toadeh]

Great replies. Thanks very much guys and especially @Martin Meredith really appreciate the advice.

Good thinking on the 290 v 224. I think for a start I might be best to go for the lower number and see how I get on. As I've said, if it works, I'll end up chucking money at it so thanks @R26 oldtimer

And also thanks to @Deflavio for the info too. Much apprciated!

Thanks all!

[London_David]

All good advice above (especially that the faster the f ratio of your scope the better it is for eaa) so I’ll stick to details on the cameras.

I have the 290mm the 224mc and the 294pro. I’m on the verge of upgrading to the 533. I’m also a Mac user. 

Those are the four cameras I’d be looking at still. 

The 290mm is easily my favourite. But you need to be good with mono. I’m quite happy observing stuff in black and white if I can see detail and structure. It reminds me of the old image plates from observatories. I still think the 290 is the best bang for your buck you can get at the moment. It’s small, fun, frame files are not big and most of all the 290mm just sees more stuff in the dark. I’d even buy one of the minis as a second b+W camera just for fun if you have the money. Do not, however, buy the colour 290mc. 

If you want colour the 224 is the cheap option and the 294pro is substantially better but more expensive. It would be true even without the cooling on the 294pro. I’d say you get a couple of magnitudes deeper with the 290mm than you do with either colour camera. The 224 is noisier and just a bit more limited. 

However, the 533 is the top pick for me. I don’t own one but I’ve been doing a lot of research on it... Having looked at the discussions on cloudy nights and examining the new chips specs it’s the first real bump in performance in a few years. A lot of the camera features for a while have been more advantageous to ap. The 533 seems to have similar (maybe even better) performance than the 290mm but in colour.

If the 533 is out of your price range and you still want colour, then the 385 is the next camera down that I’d be looking at. Probably above the 294pro. Performance wise they’re similar but the 385 probably has the edge for eaa while the 294 has the edge for ap and applications where cooling is helpful.

And for mono... the 294mm is the top of the line at the moment  - expensive though. 

fov - the 294 abs 533 are much bigger sensors with far more real estate. This is good and bad, mainly good. The bad is that each whole frame can be a large file size abs slow to write to the computer. The good is that you can get much bigger (or multiple) objects in view. Also - with all those sensors you can crop in so it only reads a small part of the sensor. That means the fov you see on astrotools is actually the _biggest_ image size, if you only care about a planet or a small galaxy you can have the sensor crop in to read a small part and the file size will reduce and it will speed up the read.

ZWO - I like the zwo cameras a lot. They’re helpful in the forums, keep releasing new products and the gear is reliable and well made. The people that run the company (Sam I think his anglicised name is) are astronomers themselves and clearly use their own gear. There are other manufactures and cameras and a lot of them use the same sensors so the performance will be similar or even the same. The main difference will be in some of the buffering systems and build quality. For me, I be been very happy with my zwo camera so I’ll probably keep buying from them especially since they seem to always be first to market with new tech.

Amp glow - is not something I’ve worried too much about unless it’s ap. A lot of the objects I look at are small and don’t cover the frame. Also, it’s easy to sort if you have software that can apply darks in real time. Amp glow is actually most noticeable on the 290mm and 224. The 290 can be quite bad actually, but I sort of forget it’s there because the camera can see in the dark so well. The 294 does have amp glow too but most of the criticism has come from ap useage. For ap 294 is great especially because of the full well depth but it does have some problems that the similar asi1600 doesn’t, so there have been mixed reviews about it.

Pixel size - the quick rule of thumb is that on ccd cameras bigger pixels are better, on cmos smaller pixels are better - even that means you are over sampling. On any of the zwo cameras mentioned here the read noise is low so you can bin with effectively no penalty. That makes the camera even more sensitive. In addition, on the nights you have great seeing, you can get better images. Also, I’ve found that some nights you can go to very short exposures (under 1s) for dso and get even more detail than you would expect - lucky imaging works if the camera is sensitive enough which the 290mm is close to. Since I live near the center of London with the highest levels of light pollution, I’ve been trying to get detail over depth these days since I bottom out due to sky glow. Not that there’s been a lot of clear nights here this summer...
 

Macs... unfortunately macs are not well served for Astro software. The asi software is good though it’s limited compared to something like sharpcap. I tried lots of things and in the end gave up. I bought windows 10 to use with parallels which I run on the Mac. I also bought a small windows 10 pc for the telescope. I use both, mainly I Remote Desktop from my Mac to the windows 10 scope at the telescope. I can do that wirelessly from inside my warm house... if I’m at the scope or out and about I’ll hook up the Mac running windows and not use the mini pc at all. Software wise I use sharpcap pro which is excellent. It is feature loaded and you don’t really need much else.

If you really can’t stomach a windows machine and nothing on the Mac is going to work for you, the asiAirPro is a really good option. 

The one bit of excellent Mac software is Jocular - which Martin - who created it - can tell you more about himself if you ask! It’s a bit more complicated in the set up, but I really like using it with my 290mm. Last time I checked it didn’t do colour. 
 

So, to cut a long story short... I’d get the ASI533 if it’s in your budget!

Edited October 2, 2020 by London_David