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Sky-Watcher Star Adventurer 2i Star Tracker

The Star Adventurer on a 055 Manfrotto Tripod

I have been using the Star Adventurer 2i for four years now and it is a mount that has enabled me to capture some beautiful astro landscape images and also photograph objects in the deep sky. When I first obtained this mount, I had no idea I would be venturing deeper into the sky to photograph galaxies like Andromeda, or star clusters close up like the Pleiades. When I first received the mount in 2020, I practiced first in my garden and I recommend all users do this where possible.

The Build

Unpacking this star tracker, the first impressions are that is is solid and well built. It requires a tripod (ideally carbon fibre to minimise vibrations, but I have photographed plenty with an Aluminium tripod and it has been fine). This star tracker comes with Wifi, and I will discuss later why this is such a boon if you want to keep things as simple and efficient as possible when shooting under dark skies. Save for the plastic reticule, used for polar alignment, the build of the SA 2i is of very good quality. The knobs and dials all have a quality feel to them and the mount can be powered by x4 AA batteries (I use rechargables), or via USB connection to a powerbank - a really nice function and quick to connect in the field. The pro pack, comes with a metal declination bracket and counterweight (I bought an extra weight for balance - this is crucial for great tracking at 200mm). There is also a ballhead attachment, which I use for astro - landscape pictures, allowing focal lengths of about 85mm and under to be attached via it. The polar scope is nice and clear. I do recommend a right-angled polar scope attachment, to save your neck when trying to align. The included equatorial wedge is of good quality - and much better than some other star trackers in this price point. It has never given me an issue in terms of it’s overall build quality.

Declination bracket for long lenses showing the polar scope connected over this for polar aligning

Polar Aligning and Balancing

When getting setup in the garden, the first challenge is to setup the SA in proper polar alignment and the mount being properly balanced in order that it functions and tracks well. This seems daunting it first, however with some practice you will get faster and better at doing so, like any task. In the northern hemisphere this process is simplified by requiring only to align to one star - Polaris. What you will find is, Polaris isn’t exactly the North Celestial Pole. The NCP is actually located in a circle around this star. The Star Adventurer app, which can be downloaded from Play store, enables information on how to align everything, depending on your location and the time of night. When I first received this star tracker, I luckily had a clear night a few days later (doesn’t always happen), I started with an 85/1.4 prime to give me a bit of a challenge. Polar aligning involves attaching an individual plastic part - a reticule into the SA which illuminates the polar scope and enables alignment. I was pleased that I could get 4 minutes right off the bat with the alignment I set. I didn’t try any more than this as I was pleased I could achieve pinpoint stars for 4 minutes at this focal length. Balancing involves moving the counterweight on the declination bracket so that with the clutch disengaged, no resulting motion occurs. It’s a case of bearing in mind some basic mechanics: Moment (turning force) = F (force) x D (distance). Put simply, use the lever arm on the bracket to place the weight in the place that causes no motion when the mount (clutch) is unlocked.

Nikon Z 8 and 70-200/2.8S with proper configuration and Declination bracket use

Using Wifi and the app

As I alluded to earlier, the Wifi functionality and the Sky-Watcher App really bring this system to life, and make it very simple to use. Classically, if you wished to control a deep sky session with a camera and a mount, you need to use either a laptop, an Asiair, or at the very least an intervalometer connected into the camera. The great thing about Wifi funcitonality, and the app, is that I don’t need any of this extra clutter when I am outside freezing myself to death photographing deep sky objects. I can simply connect to the mount via the phone app, and all I need is one cable running from the camera into the mount. From the app, I can control exposure length, spacing between exposures and even dither in one axis. (Dithering is a process that involves instructions for the mount to move the field of view slightly between exposures so that when stacking images, things like fixed pattern noise and other nasties such as hot pixels get cancelled out of the stack). Essentially this process improves your data and I nearly always use this. Wifi in this mount (indicated by the 2i in it’s title) might seem trivial, however it has made everything so simple to use. I previously tried an Asiair with DSLRs and found it fiddly and had issues with live view. I get very little time under dark skies. I either have cloud, or worse rain, or extremely high winds, or a moon to contend with. On nights that I have time to do this, I don’t want to spend time with laptops and cables running all over the place, troubleshooting one problem after another, with a setup that takes an hour to start shooting, then the same time to break it down at the end of the night. Speak to any deep sky astro shooter - they will tell you they have wasted many nights not taking images. Instead they have been tearing their hair out trying to fix some random technical issue.

The Star Adventurer app is simple and well thought out with no connection issues ever

What can you achieve with the SA?

Essentially, this mount is suitable for tracking skies from extreme ultra-wide angle focal lengths, such as 14mm right up to about 200mm with decent exposure times, with no guiding. I am able to get pinpoint stars at 200mm with 2 minute exposures (be aware of course, that 200mm and 2 minutes needs practice to nail consistently). People are shooting this mount at 400mm and even 600mm, but bare in mind they are binning a portion of their sub exposures due to periodic error and completing very short exposure times of 30 seconds or less to prevent trailing. I have been asked before why I don’t guide - I see many shooting at 135mm-200mm and adding in guiding, it is just not required, as I am proving. None of my pictures are guided! Remember what I said earlier: simplicity is the greatest invention, Guiding would add another camera and cables into the mix, with all the problems associated with it such as laptops and Asiairs to control the device. I will say though, that if you are shooting with a large equatorial mount at a focal length of 600mm and up, you know what you need and it is obvious that to achieve decent exposure times, such as 3-5 minutes - you are going to have to guide. However, we are not speaking about that. I suggest you place the limit of this system at 200mm and forget guiding. If you want to try some ultra deep pictures for fun on this mount, go ahead but keep the exposures short. This system isn’t really meant for that. That would be where the larger mounts come in to play.

About 4 hours of exposures from bortle 4-5 using the above setup

Small Deep Sky Objects with the SA 2i

So since I have said we are topping out at 200mm for the most part, how do we fill the frame with small objects? Well, the answer is: we don’t, but there are several strategies which will help. The first is looking at your camera. I recommend a high megapixel camera, shot in crop mode, or a crop camera. The reason for this is, generally speaking you will get more pixels on target and fill the frame with them better. For example, a Nikon Z 8 (45MP full frame sensor) shot in x1.5 crop mode, gives just under 20 megapixels. The second part to this is enacted in post processing, called drizzle. So let us take Andromeda as an example. Now it isn't the smallest deep sky object, but having it fill the frame is hard at 200mm, but as you can see, I have made a half decent picture of it. Part of this is down to when you process the resulting stacked image, the object physically gets larger. After we have put the camera into crop mode, or selected a x1.5 crop body to begin with in PP, we can do something called drizzle integration. This was developed by NASA. This is a method of obtaining more detail in your resulting file, meaning, if done correctly, we can produce a file larger than 20MP, perhaps put it back to 45MP, and thus crop it much more aggressively in post, enabling a closer view of your deep sky object. To benefit from drizzle, you must have a lot of data, multiple hours. The data also must be dithered, as I mentioned earlier - this mount allows for that. If you are using another mount that doesn’t do this - then this technique won’t work. This along with the other points raised here is one of the many reasons I highly recommend the SA 2i.

Comet C2022 E3 (ZTF) shot with the Star Adventurer mount and a 70-200/2.8 lens, Camera - Nikon D850

Nikon Z 8 Camera

A Mini Review from Summer 2023

This is a long one, with some rambling, so get yourself a drink and get comfortable!

So I have mainly been a DSLR shooter for well over a decade. I have multiple bodies - from a D200, D700, D810 and a D850. The Z 8 was my first buy in to mirrorless, as I felt it was a d850 in a mirrorless form. I think this is a fairly accurate view despite it also being a baby Z 9 if you take for granted that the Z 8 obviously outstrips the 850 in focus, FPS and video modes. I will be using this camera to do astrophotography - both astro landscape, and deep sky. Along with plenty of regular landscape photography and portraiture. So I don't require great speed or fps but the other aspects of this body finally drew me in to Nikon’s Z mount.

First off...the Z 8 is beautiful: It looks stylish. It is sleek, curved but carries the hard edges synonymous with the Z mount styling. The top screen and clover layout of buttons on the top left of the body have made a return in mirrorless world and this is a great thing indeed. I like the LCD monitor which flips both ways and is highly detailed. It takes time to feel confident opening and closing it initially though. The playback and menu buttons have moved to a more logical placement on the bottom right ala the Z 9. Button placement is nicely done and there are plenty to limit menu diving like Nikon’s previous mirrorless bodies. (It is however, annoying however that Nikon took the VR switches off it's lenses; forcing a menu dive). Customisation of the Z 8 is excellent; you can be confident that you will be able to set up everything how you like it to be. The focus mode button is back. The grip is comfortable and really reminds me of the 850. The light up buttons: a boon for Nikon but a crying shame for Canon or Sony shooters that don’t have this! The EVF / LCD switch easily, automatically when appropriate, and this has been well implemented overall. The EVF is bright and smooth (it drops into choppy mode to save energy at times, the time at which it does this can be user adjusted or shut off completely and kept ultra smooth. I find the EVF resolution good, especially when reviewing photos I can see and zoom to check focus has been attained with no problems. The LCD monitor is great, ala the D850 and it tilts in both axes finally, something I believe should have been done along time ago in DSLR land. Battery life is not very different to me compared to a D850 because of the way I used the D850. It was mostly used with the LCD monitor on - thus there is no change in this aspect for me. If you only used OVF, you should buy an extra battery or two. I did wonder if I'd get the same life as say shooting the D850 with LV only vs the Z 8 in 'LV' mode and I do. This was important as I spent a lot of time with the d850 in silent mode, using the LCD exclusively. This limits shutter wear on deep sky astro and landscape time-lapse and prevents vibrations. Another logical reason to get the Z 8 for me, I thought. I love the extended shutter speeds up to 15 minutes. I don’t really use the 10-pin socket much at all now, (however I do need that for connecting into my star tracker so I am glad it still exists) and I used to extensively because I am a long exposure photographer for a lot of what I do - either during the day or at night. This has improved my user experience as dealing with remotes generally speaking can be a faff. This is however, a function should have been in DSLRs years ago. (I note the Z7ii had this). Further to this...I have always said to myself that a Z 8 will not, for the most part change my photography and that's fine, you wouldn’t want that to be the case anyway. For me it is going to he about user experience and new possibilities. This leads me to starlight view. This is a huge boon for someone like me who spends nights under dark skies. No longer do I have to stand about wasting time with high ISO test shots on rare clear nights that we get here in Scotland. I can compose with starlight view fast and easily, then take the shot. This is quite liberating! It also helps in deep sky photography to frame up the target (more on this in the coming months perhaps). I can feel more connected to the scene now and have now with me, night vision, it is so sensitive it will pick up faint aurora in this mode, that my eyes cannot see. This along with the screen means I stay warmer and get shooting faster. I'll no longer need to lie on the ground to get those vertical shots. I'll also be able to easily power the camera all night with a battery pack and a simple USB-C connector. Autofocus from what I have seen so far is excellent. The new processor really bests previous Nikon mirrorless models and although I still find myself moving points about, I like the large boxes and letting it find eyes within them etc. Even with my 24/1.4G nikkor through the FTZ II, it nailed most shots of my son fast moving towards me. Simple stuff affects user experience!

I would like to see some minor things. It might just be me but I would like the option to see a battery percentage like my phone rather than these little 90s looking blocks of a battery to simulate remaining battery lifespan. I'll live though. One thing that I did notice...the on off switch is very 'sharp' feeling compared to the DSLRs. I understand the ‘Z’ styling but let's not cut our fingers Nikon, again I can live with it. (2024 edit - I strangely got very used to this now and don’t notice it). Okay elephant in room for anyone that is serious about data collection. RAW histograms. Granted this isn't just Nikon; all the camera companies need to take this seriously; especially at this price point. This would really allow pushing the data as far to the right as possible (the shot on the monitor would look terrible but that would be corrected later - you would achieve technically perfect exposure for the sensor that could be developed and worked on in post processing). I can get close to this without RAW histograms, but just that little bit more would be nice since we are shooting with a ‘big boy’ camera. I'd like to see Nikon provide a mode for deep sky astro guys like me to turn off the peripheral shading correction applied to RAW files or any data filtering on the files applied to assist with daylight photography, which can sometimes cause concentric rings to form when stacking hours of data of a night. (More on this as I test). Couple other minor things spring to mind that Nikon should be doing. Nikon ought to allow adjustment of the f/5.6 aperture when focusing at f/5.6 or smaller apertures by way of a menu function, for example in studio with strobes or speedlights the system can struggle because it is trying to improve focus shift by focusing stopped down. This has an obvious detrimental affect on focus precision and it should be that Nikon allow an on/off of this function for studio guys, eg a setting that allows ‘force focus at maximum aperture always’. Allow me to resize and move the histogram on the EVF and LCD monitor. I repeat this again...RAW histograms too! Oh and one more. LCD automatic brightness. Nearly all phones do this. They go up to max in bright sunlight and dim back when we go inside. This shouldn't be a thing at this price point to have to manually adjust it every time. The Nikon D800 had this and then it has never returned in a Nikon body since. People need to learn to expose properly and easily get confused with LCD brightness, however I believe it should be a function for those that know. Nikon should allow the inbuilt profiles to be disabled whether or not they are enabled / disabled in the camera menu. I am hearing and experienced with some lenses they stop you enabling a vignette correction for example unless you had it enabled in camera initially (the metadata in the RAW file passes to Lightroom - if it ain’t in there, it ain’t coming up in LR to be able to correct it, save for f mount lenses through the FTZ II adapter). This makes little sense and is not helpful. Crop modes. Why the heck so we not have 4:5 I will never know? Someone at Nikon has physically went in and took this out from previous models! It is quite stupid of them and they should put it back in and avoid more nonsensical stuff like this going forwards…(2024 update - still no 4:5 crop mode in camera, you know, the one that has been in the D800, D810, D850 but now is missing in action. Nikon, come on!).

Apart from these minor gripes I cannot fault the Z 8. It is literally what I hoped it would be. Paired with my initial lens of choice, the 24-70/2.8S - can produce absolutely stellar results, in fact some focal lengths on that lens approach / beat prime like sharpness, details and rendition. I am very much looking forward to doing long exposure photography with this lens. (2024 edit - oh it is good!). This was another reason I wanted a Z 8 and to go mirrorless with Nikon. This lens is that good; it is probably the best in class 24-70/2.8S ever made for any 35mm format.

Lastly video. Very impressed. Especially with the 24-70/2.8s which is pretty much silent and just holds focus to the subject. I am enjoying not having to focus pull manually! I am not a huge video shooter, however I have been doing more of this. They need to look at waveforms and a couple of other functions for the really serious video guys but I have to say I am seriously impressed as Nikon’s video implementations have classically been lacklustre and this has all changed now.

So what's next? I am waiting to see what Sigma do with regards to primes. I would honestly bite their hand off to get a native 14/1.4 (I love their 14/1.8 for f mount and still own it). I would like updated 24/1.4 and 35/1.4 and 50/1.4 primes from sigma for Z mount. Nikon’s 1.8 offering does not have class leading aberration correction, albeit is fair. Nikon’s 24 and 35 1.8 lenses released really are so-so lenses when it comes to a serious astro shooter like myself. I looked at their 1.2 glass for a second knowing the conclusion I would probably form quickly - they are simply too massive and heavy to use on a star tracker, what’s worse, they offer no benefit. I cannot shoot them at f/1.2 (no one can make a reasonably priced, shootable f/1.2 prime lens for astro, believe me). For me, the perfect balance has always been f/1.4 with good correction. Give me 1.4 for aurora and meteor showers (think clear aperture, see detailed explaination here), and enable me to shoot at f/2.2-2.8 with clean stars into the far corners and I am happy, relatively.

What about DSLRs? I sold one...my D850, as it had high value and helped to partially fund the Z 8. I'm keeping the rest, and might even pickup a mint d810 as a spare to my current d810. I love OVFs! As much as I love the Z 8 EVF and the bells and whistles it brings...I think I'd personally prefer to stare through an OVF all day if shooting sport or wildlife as any EVF is technically like looking at a TV screen. If I shot sports, I honestly think I would have stuck with OVF for a long time, or perhaps forever. The way most modern landscape photography is carried out is via the screens, no the OVF, so you can see why mirrorless mattered to me. (Regarding the Z 8, I mention this, not because the EVF is bad in the Z 8 - it isn't, and not because I am an old timer; I am not). Again this comes back to one of the many reasons I wanted to grab the Z 8 body - I don't use the finder as much on that body anyway. 10 years ago I'd have sold everything and went mirrorless then ended up realising my mistake and having to buy back some DSLRs for different purposes. Using the principal of ‘tool to task’ - there has never a more pertinent expression when it comes to deciding on a camera and lens to work for your needs rather than against.

Sligachan Isle of Skye Long Exposure — Snowcapped Cuillins from Sligachan, Isle of Skye. Z 8 with 24-70/2.8S

Nikon really aimed high here and got it right, for the most part. The price was / is high, however it will come down. I bought quickly like the d800 days, as I have been waiting a long time (how those savings accumulated thankfully). I applaud the lack of shutter in this camera. I think it was the right decision and will likely make the camera last even longer than it would otherwise. Like I said...I think shooting studio flash work I'd be using an OVF but that's just me...we have to consider that these aren't custom made cameras to our own specifications; however that non withstanding, logical upgrades and firmware adjustments where appropriate can certainly be requested, and debated.

Some further thoughts which I will continue to add to for those on the fence. I updated my 24-70/2.8 lens firmware there to 1.20, in order to take advantage of linear MF, now activatable in the menu. I must say, the focus throw can be made huge (720 degrees and over) and it makes focusing manually butter smooth. I am interested in this for critical astro applications (albeit not in particular with this lens), but this will be great for landscape photography which is mainly where I will use this lens. I like to do the focusing manually and confirm it is optimal for the scene. Combined with starlight view, this is going to be amazing at night. (2024 edit - it is). The 20/1.8 will be good to use with this feature. This should really allow me to nail balance between the centre frame and corner to manage astigmatism and coma, which was a nightmare with DSLR monitors at night which where made less sensitive - they sat at 60 FPS even in darkness which is pointless! In DSLR land (especially the earlier models) it was hard to actually see the stars sometimes in order to do this critical focus pull, ironically one felt a bit blind at night. The 14-24/2.8 tempts me for astro and landscape use but I note it does not have this feature - I wonder why, and hope they will bring it to it. I love to get critical focus in landscape manually, too. (2024 edit - I now own this lens and have been using it for about 8 months’ now - it is indeed very easy to compose an UWA shot with starlight view).

Following on from this, I still cannot believe how bad Snapbridge still is all these years on. It can barely connect half the time, and if it does it disconnects, fails 3/4 of the way through the process (and it can take while to get there, fail and you have to restart the process and hope it will work). Nikon please hire a better software person, an app person please. This is not a Z 8 complaint but since it could be an amazing part of the Nikon ecosystem I mention it here. Why am I still having to remove a card from the camera to update firmware on a lens? The camera can connect (should be able to) to Snapbridge, and it should be a simple option there to update lens or camera firmware going forwards? I cannot see one, nor connect right now to confirm however it is very clunky for 2023. It really would be great if this was fixed and improved overall for user experience. (2024 edit - Snapbridge is a bit better, and firmware can be updated via Snapbridge, so some improvement here).

Lastly can I point out how well built this 24-70/2.8 is? It is also so sharp right in the corners at most focal lengths and apertures it really can sit with the best of lenses, fully sealed and it looks smart too, still remaining one of the lightest 24-70/2.8 lenses ever and probably optically the best which is no mean feat. (PS the display button should automatically adjust to outdoor and indoor brightness, like I previously mentioned that the back LCD should too ala phones). Nikon, if you ever update this lens, put in the VR switches on the body please…

Ramble complete,

Steve