Is the DWARF II a Viable Astroscope?

[DaveC426913]

TL;DR Summary

Portable video scope startup seems nonviable out-of-the-gate, and it's not even out-of-the-gate yet.

I stumbled across this scope and was morbidly curious about the light gathering ability of such a tiny lens. I see it uses tracking and long exposure times to achieve its goals.

https://igg.me/at/DWARFIIFB123/x#/faq

But does it achieve them at all?

"Based on the parameters of the camera, DWARF II is suitable for the DSOs whose angular size is above 15 arc minutes and the apparent magnitude is below 9, such as NGC2264, NGC5128, NGC6960, NGC1499, M6, M7, M8, M16, M17, M20, M41, M42, M44, M45, M81, M101, IC4604."

> 15 arcminutes?
< mag 9?

Unless I'm mistaken, that list of things it can resolve is actually exhaustive. i.e. it is useful for 17 items, and that's all.
Is it possible they've actually built a "scope" that can't see stars? Or planets?

Can this be even classified as an astro scope?

https://en.wikipedia.org/wiki/Angular_diameter
https://en.wikipedia.org/wiki/Apparent_magnitude

 

[Drakkith]

Well, it's a 25mm aperture lens with a 100 mm focal length, so it's F/4, which is nice and fast. I don't quite understand why an F/4 system would be limited to only mag 9, at least for extended objects, unless it is because of the 15 second exposure limit. I'd like to know which exact sensor they are using.

 

[DaveC426913]

... why an F/4 system would be limited to only mag 9...

Isn't it because light-gathering ability is directly related to aperture?

 

[Drakkith]

Isn't it because light-gathering ability is directly related to aperture?

For extended objects, not point-like objects, it's the f-ratio that matters. A 100 mm F/4 optical system has a quarter of the light gathering capability of a 200 mm F/4 optical system (objective diameters of 25 and 50 mm respectively), but the 100 mm system concentrates that light into a quarter of the area of the 200 mm system. Of course, the 200 mm system will potentially show more detail since it is zoomed in further.

And things like sensor pixel size matters as well. Double the dimensions of each pixel on the sensor as you move up from the 100 mm to the 200 mm and you'll counteract the increase in the image size. Each pixel will get 4x the amount of light at the cost of not getting that increased resolution from the larger scope.

 

[DaveC426913]

So what is your verdict on this scope? Does it have a purpose (niche or otherwise), or is it off the bottom of the chart, as I think?

 

[Drakkith]

Unless you are looking to do REALLY wide angle photos then there's not much point in getting it for astronomy. It's got a 5-degree field of view and gets roughly 6 arcsec/pixel, so small things like planets are only going to be a few pixels across at best with virtually no details.

That being said, if you're looking for something to do terrestrial work then it might be okay. But I can't comment too much on that aspect as I don't even own a non-astro camera except for the one in my cell phone. Perhaps it is originally designed for terrestrial imaging and the astro stuff is just an afterthought?

 

[DaveC426913]

Perhaps it is originally designed for terrestrial imaging and the astro stuff is just an afterthought?

I think this is improbable in the extreme, since the mechanical tracking servo component is pretty much the core of the device:

IOW, without the mechanical ability to track sky movement, this device would not exist at all. It would be ... just a camera.

 

[Drakkith]

I think this is improbable in the extreme, since the mechanical tracking servo component is pretty much the core of the device:

Perhaps, though that same design functions perfectly well for tracking terrestrial objects as well. And I wonder if one of the reasons the exposure length is set at 15 seconds max is because they don't include a rotator to counter field rotation on longer exposures.

 

[DaveC426913]

...that same design functions perfectly well for tracking terrestrial objects as well.

Such as?

 

[pbuk]

Is it possible they've actually built a "scope" that can't see stars? Or planets?

It is designed for viewing deep sky objects (DSOs) not stars or planets, although any star or planet that is bright enough will be visible.

Let's do some maths: they quote an angle of view of 3 degrees = 3 x 60 x 60 = 10,800 arc seconds and it has a Sony IMX415 sensor which is about 3,840 px across so 2.8" per pixel. Saturn's rings average about 38" so that's about 13 px across - enough to see it's not a simple sphere but that's about it.

If you want to observe Solar System objects on a budget get a 4 inch refractor.

 

[collinsmark]

So what is your verdict on this scope? Does it have a purpose (niche or otherwise), or is it off the bottom of the chart, as I think?

I'd go with niche.

It might have a fair application in nature photography, such as setting it up on a tree branch, not too distance from a target bird nest, and then control the camera remotely such that you don't risk disturbing* the birds as they do whatever they do in the nest.

*(It is a tenet of nature photographers that you should take precautions not to disturb the subjects you photograph, and also have no more than a minimal impact on the surrounding wildlife.)

Or maybe it could be useful for nature-photography situations where the best point-of-view is in a precarious location like a cliffs-edge, and you'd rather control the camera remotely rather than hang around half-way over the edge. Or similarly, it could be useful in a situation where the subject is a wild animal that might eat you. The camera's automatic tracking feature might come in useful here.

The last thing I'll say about nature photography, is that even with the tech, it's still very limited. Having such a small sensor and lens restricts your ability to dial in optimal depth of field and shutter speed. (and I haven't even mentioned poor shutter lag). I would not want this camera as my main nature photography setup. Rather it's just something that might be useful in certain situations, perhaps.

Maybe it could be useful for paparazzi to set up the camera somewhere with a good view of the celebrity's backyard, and then control the camera inconspicuously from his parked car nearby.

----

But for astrophotography? Good god, no. Not in my opinion. Certainly not if astrophotography is your primary goal.

The system is self-contained and not upgradable. It would seem to have a very small sensor with small pixels. Combine that with the 15 second limit exposure time and read noise would be the dominant noise source in any astrophotography situation. It's very inflexible.

The camera will allow you to take a picture of given deep sky object (DSO), but not a good one, really. It will be a picture you can show to your friends and say, "Hey look, I took this picture of M101 myself! Sure, it's kind of a crappy picture, but it's my picture!" And you can do that without investing countless hours of research, study, and trial & error that most of us astrophotographers go through to get a decent image.

And I get that. I understand the motivation. If you want something quick and don't want to put in the work, this camera might temporarily fill that niche.

The buyer's remorse doesn't set in until later, until you compare your picture other astrophotographers' images. Then you ask yourself, "how can I make my M101 picture better." And then it hits you: There is absolutely nothing you can do with this DWARF II system to improve the image. There is 1 and only 1 option to take if you want a better astrophoto image: get an entirely new setup from scratch. Everything -- the whole kit and caboodle (maybe you don't have to throw out the tripod). And in the process realize that the entire $628 you spent on the DWARF II is gone. That's money that could have gone to a good startracker or telescope.

At least with conventional astrophotography approach, you can usually improve incrementally, without completely starting over. E.g, get a star tracker, improve the gain/ISO/exposure time settings of the camera, Upgrade this doohickey here, or maybe that doohickey there. Maybe add guiding. This process can eventually get expensive (very expensive)** but there's always a path forward, and that path won't be limited.

**(not to mention this track can be overwhelming for a lot of people. It's not for everybody. But if your primary motivation is astrophotography, you are probably already willing to be overwhelmed from time to time -- It's part of the process.)

 

[Drakkith]

Such as?

Wildlife, people playing sports, etc. Whatever you want to take a picture of.

 

[DaveC426913]

Wildlife, people playing sports, etc. Whatever you want to take a picture of.

But you can't take long exposures of those things; they'd be all motion-blurry.

I guess I'm thinking that the tracking functions are pretty basic - i.e. it can track the sky.

 

[pbuk]

Why don't you watch the videos to see what it can do?

 

[DaveC426913]

Why don't you watch the videos to see what it can do?

I guess I prolly shoulda. I was really only looking at it as an astro scope (since that seems to be how they're flogging it), so I was really only concerned with the optical specs, not the compensatory gimmicks.

 

[Drakkith]

I guess I prolly shoulda. I was really only looking at it as an astro scope (since that seems to be how they're flogging it), so I was really only concerned with the optical specs, not the compensatory gimmicks.

Oh, it's definitely not an astro-focused camera.

 

[pbuk]

Oh, it's definitely not an astro-focused camera.

Well it should be good for the Moon and (with an appropriate filter) Sun, and if the tracking and stacking work well enough, good for DSOs too (which is what they are marketing it for).

The kickstarter pack costs less than most computerised mounts and tripods so if it works well I don't know of a cheaper way to get into DSO photography.

 

[DaveC426913]

Oh, it's definitely not an astro-focused camera.

Well, "stargazing" is the first word in its sales pitch.

 

[collinsmark]

I might be getting on the hair edge of off-topic with this post, but I wanted to do a follow-up.

[...]

The buyer's remorse doesn't set in until later, until you compare your picture other astrophotographers' images. Then you ask yourself, "how can I make my M101 picture better." And then it hits you: There is absolutely nothing you can do with this DWARF II system to improve the image. There is 1 and only 1 option to take if you want a better astrophoto image: get an entirely new setup from scratch. Everything -- the whole kit and caboodle (maybe you don't have to throw out the tripod). And in the process realize that the entire $628 you spent on the DWARF II is gone. That's money that could have gone to a good startracker or telescope.

At least with conventional astrophotography approach, you can usually improve incrementally, without completely starting over. E.g, get a star tracker, improve the gain/ISO/exposure time settings of the camera, Upgrade this doohickey here, or maybe that doohickey there. Maybe add guiding. This process can eventually get expensive (very expensive)** but there's always a path forward, and that path won't be limited.

[...]

If you have a little over US $600 and you want to start as a beginner in astrophotography, a start tracker/mount like this might be a better use of the money:



Cons of the star tracker/mount approach:

• The listed preorder price of $640 doesn't come with the tripod (that's an additional $389), camera, or telescope/lens. So, yes, the total cost will be higher with this more flexible setup.
• The learning curve might be a little bit steeper. (But then again, if you're interested in astrophotography, learning the basics is something you'd probably want to do anyway.)
• The star tracker/mount is specifically for astrophotography. It does not double for nature photography, even in niche situations.

Pros:

• It's very flexible. You can upgrade your setup without having to start from scratch. There's many, many ways to improve upon your setup while still using the star tracker/mount. Even if later in life you upgrade to bigger and heavier telescopes, which need a beefier mount, the star tracker will still be useful for wider field targets to be imaged in parallel with the targets. In other words, even as technology advances, this star tracker/mount will maintain its usefulness and flexibility.
• If you're starting out in astrophotography, you may very well already have a camera, lens, and tripod (although you may need to upgrade your tripod; Stability is paramount to astrophotography).
• Even with a modest camera and lens, you are likely to get superior images with setup compared to that of an all-in-one system like the DWARF II.

 

[DaveC426913]

@collinsmark There is a whole Insights column for picking a first scope. You could add your comments to it for posterity.

 

[Drakkith]

Well, "stargazing" is the first word in its sales pitch.

Well now they're just being cheeky...

 

[pbuk]

If you have a little over US $600 and you want to start as a beginner in astrophotography, a start tracker/mount like this might be a better use

The product in the OP is USD 329.

 

[collinsmark]

The product in the OP is USD 329.

I guess I was looking at the X2 version of the DWARF II

Whatever the case, there are less expensive star trackers than the Sky-Watcher Star Adventurer GTI (that I posted the video about) as well. The Star Adventurer GTI is certainly not the cheapest star tracker out there.

 

[pbuk]

There is no X2 version, that's the price for two units!

 

[collinsmark]

There is no X2 version, that's the price for two units!

Oh! Well. My mistake, then.

So, maybe a better comparison would be the original Sky Watcher Star Adventurer that retails for USD $350.
https://optcorp.com/products/skywatcher-star-adventurer-photo-package-s20520

It doesn't have GoTo capabilities, but then again the DWARF II doesn't have GoTo capabilities either (as far as I can tell), so this is probably a better comparison anyway.

 

[collinsmark]

Here's an unboxing video from Cuiv.

I've already posted my thoughts on such devices. I won't go into detail, but the summary of my personal opinion is:

• If you're at all serious about astrophotography and look forward to improving your gear and setup as time goes on, there are better and more flexible solutions out there.
• But, -- but -- this does fill a niche. It's portable. It's relatively easy to use, and has a small learning curve. If you want to jump-right-in to getting some astrophotos and don't want to bother with all the learning, and are not too terribly concerned about the final quality, this scope could meet that need.
• This system may also provide some very useful niche applications in terrestrial photography (remote use, etc).

The video is only an unboxing and Cuiv plans to do a more thorough review in a later video.

Btw, "Cuiv, The Lazy Geek" is one my top five favorite astrophotography YouTube channels. He approaches subject matters very objectively and scientifically. If you're interested in astrophotography, I highly recommend subscribing to his YouTube channel.

 

[collinsmark]

Here's Cuiv's (as in Cuiv, The Lazy Geek) followup semi-review of the DWARF II.

Summary: Very promising, although needs some software UI enhancements.



(By the way, for those wondering what "Electronically Assisted Astronomy" (EAA) is, it's very much like astrophotography, except immediate gratification is held high above all else. It's like astrophography modified such that you need an image now, now, now, right now. Stacking, stretching, and color adjustments [and possibly dark frame subtraction] are all done like in astrophotography, but they are of course automated such that an image can be displayed right now, now now, now.)