Astromedia Solar Projector Review

[Someblokius]

Astromedia Solar Projector - https://www.firstlightoptics.com/astromedia-astronomy-model-kits/astromedia-the-sun-projector-kit.html

 

Introduction

If you are unaware of how putting telescopic optics, cardboard and the Sun together can produce fire then you had a much more responsible childhood than I did. This is a papercraft (actually fairly dense cardboard) kit that uses a 30mm lens and mirrors to project an image of the Sun onto a card screen. What could possibly go wrong? I'm middle aged now but I still like astronomy, I still like model kits and I still like starting fires, so this thing had to be tried out.

 

Assembly

My first impression of this kit was surprise that the lens was actually a 30mm glass doublet. I'd been expecting plastic. My surprise was calmed a little when I saw that the lens is actually stopped down to 23mm, '80s toy telescope style. But enough nit-picking about optics. I judge cakes by their taste, not their ingredients. It was time to start assembly.

At this point I hit my first roadblock. The instructions are terrible. A certain large Scandinavian furniture company has realised that by making instructions largely pictorial they can be made clear and useful with minimal translation needs. Each step of building your bookcase can be made simple with a diagram showing what goes where and in which orientation.

Astromedia seem to have made the opposite decision. The pictured page of the instructions is typical. You get a couple of photos illustrating each page, usually showing the end result of a subassembly when you'd prefer to know how the components go together. What you actually get is a dense, small-print nightmare, verbally describing a process that would be so much easier to visualise if there was a diagram. It's possible that I am being unfair here. I doubt that (the assumed) translation has done the text any favours. Drawing diagrammic instructions might well not be cheap. But being a reasonably avid wargamer I couldn't help but wonder how much better instructions a certain large UK wargaming miniatures company would have made.

Having panicked at the instructions I had a revelation. People are going to buy this kit to do with children, right? What do kids do if they can't do a thing?

I went to cry to my big sister.

She's big on arts and crafts stuff. She scratchbuilds paper flowers that look shockingly realistic. She has [deleted due to terror of sisterly wrath] years of making stuff out of card and paper. No way she was going to be intimidated by some weak instructions. The kit was as good as built.

She dragged me in to help with the instructions, because she thought that they were terrible.

In the end we more or less managed it with only one mishap (We mounted the objective doublet the wrong way around. A minor error as I'm sure you'll agree. Correcting it took some nifty knifework but in the end we flipped it around.) One thing that did help was the big picture on the cover slip, which helped in ways that the instructions did not. In the end we got it looking more or less like the picture on the cover, which is more than many of my gaming miniatures can claim.

 

Use

Fortunately by the time we had the thing put together there was a partial eclipse imminent. We set it up on the latest "Wheelie Bin" mobile pier mounting and found the Sun. Despite the slight wonkiness due to both the wobbly bin and some minor assembly issues on the alt-az base (they call it a Dobsonian base, and I can sort of see why. On the other hand that feels wrong to me since this is not a Newtonian, so terminology rejected!) we got an image of the Sun.

It was beautiful!

 

The projector offers a pair of switchable mirrors that give images 55mm or 75mm in diameter. The image seems enormous. The image is clear, too. We settled on 55mm since the 75mm version only just fits on the screen and therefore needs constant fiddling to keep it in view. It is also naturally dimmer. Watching the partial eclipse via the projector was hassle free and social - three of us were sitting a metre or so away and it was still clear. There's a bit of chromatic fringing, which can, according to the instructions, be dealt with using a series of even smaller aperture stops on the objective. We didn't bother with them since the fringes were only visible if I practically shoved my head into the box and we didn't want to lose image brightness.

 

We all enjoy a nice equipment comparison, don't we? I also have a Coronado PST H-Alpha sunscope on a Skywatcher Solarquest Sun-tracking mount. My PST is much loved and has given me a lot of fun over the years. On June 10th though, I was reminded of its limitations. One thing I've noticed about the PST is that even a wisp of cloud seems to kill the image. The Solarquest tracking camera also needs to see the Sun to track, as you'd expect. June 10th was pretty cloudy. The eclipse was only visible intermittently until we got a long break in the cloud in the second half. By then I'd given up on the PST since by the time I had it realigned on the Sun when it returned to view the cloud got in the way again. The projector, on the other hand, gave a fine image of the Sun even through much of the broken cloud. It also has the advantage that despite being manual and alt-az it only needed to be fiddled with every five minutes or so. This meant that the Sun was usually still in the field after one of its disappearences.

The body of the projector gives a nice dark surrounding to the image. We found that glare was not an issue even when looking towards the Sun. I took a couple of images using a phone. My first eclipse photos, amusingly enough.

So in the end the fancy autotracking mount and solarscope were conculsively beaten by cardboard. Nice one, Astromedia!

 

Conclusion.

Negatives first: The instructions. This excellent kit deserves better. That's it, really. I've said enough about that.

Positives: Everything else.

I was honestly shocked by how good this thing is. (Caveat: I've not actually had a chance to see sunspots on it yet. I'm assuming that sunspots are a more challenging target than an eclipse but I can't imagine it'll be that bad.)

The projector is ideal for group viewing, particularly for non-astronomers. I've shown it to my nine year old niece, wheras I'd not show her the PST yet since I don't want to give her the idea that looking at the Sun through telescopes is a good idea. Naturally children should always be supervised when solar observing, but the design of the projector makes it very difficult to see the raw beam from the objective so I think that the projector is pretty safe. Despite warnings about the consequences of leaving the device unattended I have yet to even cause any scorching of the casing, which is testament to the foolproofing of the design. I can be quite an impressive fool.

 

I'd recommend this to anyone interested in solar observing, particularly if you want to share the Sun with someone. I'd definitely think that the £23 (FLO price) for the Projector is an excellent deal even if you only use it as an eclipse viewer. Most of all using it is simple and fun, even if building it sometimes wasn't.

[niallk]

Nice one - I have something like this, except it has a plastic tube to hold the glass optics, an f20 system.

It is excellent on sunspots Highly recommend these, and I've also used a 250px with baader solar film, and have a LS50DS Ha scope.  For the money you really cannot go wrong, and will get a lot of enjoyment,  imho!