AstroKeith

I've had the pleasure of meeting with Al and David Nagler a few times and they stand out as equipment designers who know their trade. You dont see many other designers or manufacturers attending star parties and actually 'standing by' their products.

'PD' means that the device and power supply have an initial exchange to agree what voltage and current is needed, or available. In the old days USB meant 5 volts, but with USB C PD it can be a number of voltages, including up to 20V to power laptops. The Seestar supports PD and if plugged into a suitable supply will draw 12 volts and charge at twice the speed of a 5V supply. This is important if the Seestar is being used at the same time, as a 5V supply won't have much left to charge the battery. If you search for Power banks, look for those that state USB C PD. Personally I would only ever buy a good brand lithium pack. Check out Anker. As for a specific model, that depends on your budget and how long you want to run the Seestar.

The USB C output is a PD type, so with the right cable it can be triggered to supply 12V.

Look for one that has a USB C PD output. The supplied Seestar cables won't work as you will need a full USB C to USB C cable (power & data) This will allow the Seestar to draw maximum current at 12 Volts.

Its listed in the scope set up page - so it should!

Imaging near the Zenith produces massive image rotation. Even if the Seestar can compensate when stacking, the useable field of view reduces from a tall rectangle towards a square. The image below has been black level adjusted to demonstrate - M51 was about 82 degrees altitude.

They are both travelling away from the Earth

It's a rather nice nod to the grand refractors (and a few other scopes) of yesteryear. Take a look at the back of the 36" Yerkes telescope - lots of brass, wheels and the same steering handle.

Are you sure it's red? I've only ever seen green Zygo tests. The report should also give strehl, rms and astigmatism figures.

The choice does depend on the scope focal length of course. With my 18" f4.5 dob it used to be the 17mm Nagler that hit the sweet spot. This was replaced by the 13mm Ethos. Same field of view but more magnification hence darker background and better performance on the faint fuzzies. I use the 13mm 80% of the time. It got my vote in your poll. Recently, with my plate solving finder, I find I use the 10mm more. Not having to search for the object has made a small difference. I used to have a 6mm, but didnt use it enough so that funded the 10mm. Now I have the 8,10,13,21 and a x2 power mate.

Thats good new. Typical of Serge's excellent support, despite the fact it is he dealing with someone else's product that is made with poor control of tolerances.

Just watched Ed Ting's review. I think he is right on so much - in particular it's not great image quality and much better is coming. But, I believe his conclusions are biassed. I'm a visual only observer. I go after really difficult objects and work actively to improve my own visual performance. Never gone to the 'dark side' (what I call astrophotography), since why not just look at images on the web! But I've bought one. Costs less than an eyepiece (my Ethos at least), or a week away at a star party. I'm enjoying the technology. It's a good package and must not be compared with astro-photography rigs costing £1000's. No doubt we will see firmware upgrades (post processing and mosaics). Meanwhile I'm having fun and it's something I can share with my grandchildren without them getting bored, cold and disillusioned. Heh they might even get interested in astronomy! I design telescopes and tracking systems, and ZWO have hit a good spot. Almost everything Ed wanted could double the price. Except better processing which is almost free. Even a bigger sensor might sound affordable, but it will impact the optical design (size of flat field) filter apertures, etc and prices will spiral upwards quickly. Next time I'm out with my 18" Dobsonian, there will be little friend nearby on the ground busy imaging. (Albeit with gaffer tape over the LEDs!)

Not so. A cold surface (your dome) will attract condensation if it is colder than the dew point of the air inside. Warm humid air (ie air from outside) will have a high dew point and be likely to condense. To stop this you would have to blow enough air through to dry off the surface - a lot. Its quite simple, you are getting condensation, therefore the air inside is not dry, therefore your desiccant isnt working in this instance

If you open it now, what colour is the silica gel? It clearly isnt working as a desiccant, or it is saturated. already - Laws of physics.

Well, the air in the box is saturated with water. That for sure. So either, The desiccants are saturated and/or not enough (a 50 gem pack is about minimum. It isnt sealed. Carbon Brush gave good advice, I wouldn't cook my gel at 100C though. I find 60 for 2 hours enough.