Geoff Lister

20 hours ago, scotty1 said:

I'm guessing there is WiFi on the Seestar that connects to your phone, if you have signal.

Yes. The first connection is via Bluetooth. This then turns on a WiFi transmission from the Seestar. This can then be received by your phone/tablet. Your phone/tablet may either, lock automatically to the Seestar, or, need to go via "settings" to switch from your home WiFi. There is an option to use your home WiFi for the Seestar link, but I have not tried it.

Geoff

I too, have not had significant problems with field rotation effects on the Seestar images; but I have noticed it more with my Dwarf II. If you are going to be spending hours gathering FIT files for off-line processing, you are, perhaps, missing the point of these lovely little 'scopes. They both work at their best, capturing for a few minutes, with a "Live" display on your tablet's screen, and a download of a nice JPEG image for your records, - then a quick slew to the next interesting target, and start "Viewing" again.

I found a very good web site that explains field rotation with an Az/Alt mount.

https://calgary.rasc.ca/field_rotation.htm

About 2-thirds through the document, there is a very nice 3D graph showing field rotation with respect to the target's azimuth and elevation. As far as I could conclude, for minimum rotation select targets near the horizon, and towards the east or west. Anything close to the zenith is bad for field rotation, (and anyway would be challenging for any Az/Alt mount).

Geoff

As far as I know, the Seestar does not need a mobile signal. Some of the weather and "best targets tonight" parts of the Android or IOS app on the tablet/phone require data access to the internet for updating, but I am not aware of a "SIM" equivalent to communicate with a mobile phone base station.

Geoff

1 hour ago, Paul M said:

I think that if they isssue a firmwear that can stack on a comet or other "moving" object, astrophotography will enter a new era.... actually, it has already but, anyway, you get my train of thought!  

I think that ZWO has done a great job with the Seestar - an image building-up on your screen in real-time, downloaded direct to your tablet/phone as soon as you stop capture (and with text showing basic location/date/time/target name details) and the storing of the original captures for later post-processing if you wish. No need to level the mount, or polar align; prior to the initial capture, it works out its non-level mount correction data, and then takes a set of dark frames.

Geoff

Many thanks. Nice video. My Seestar is imaging 13P/Olbers. It's showing the core moving slowly northwards, so I will stop and download from my tablet.

Done.

Geoff

As requested, hot off the tablet from another part of North Somerset

I managed to see it at the same time that the Seestar was capturing - I just stood directly behind it and pointed my binoculars at the same angle as the alt. axis.

Whilst downloading this image, the Seestar app is stacking 13P/Olbers.

Geoff

2 hours ago, paulastro said:

Perhaps the elongation is the movement of the comet due to the S50 tracking on the stars?

I was watching the image build up on my tablet's screen, and it started round and then elongated.

Once 12P had dropped below my local roof line, I went for 144P, about 10 degrees above Bellatrix,

and then 62P about 10 degrees below-east of Denebola.

After 7 minutes on 62P, the display remained stuck on 4 minutes stacked, so I stopped capture, turned on anti-dew and resumed capture. I like the way the Seestar offers the option of Restart or Continue.

Geoff

54 minutes ago, Cosmic Geoff said:

but we could really do with a proper Seestar user manual!

+1.  The nice new functions in the App need documentation.

I tend to use Stellarium to search for a target and get an idea if it is likely to be above trees/houses/fences etc., then home in using the Seestar sky map. Using that method has got me 144P.

Geoff

It is now much brighter than it was in January (see my posting above)

Just 6 stacked frames, and, recording for a bit longer

Geoff

Another one of 12P from 2nd March

Even with only 6 stacked images

It's a shame  that this comet is disappearing into my neighbourhood roof line as dusk moves later through March.

Geoff

I think that the main problem with these 5.5/2.1 mm connectors is that the plug, with its 2 metal cylinders is ok, but the equipment side, with centre pin and cantilevered spring side contact provides poor electrical contact and very poor (as mentioned above) plug retention. I have added a cable retention clip on most of my mounts that use these connectors.

Geoff

And more recently:-

62P is about magnitude 11 and IC 3602 is magnitude 15.5.

Geoff

A warm welcome to SGL. We like to help with advice where we can. There is no such thing as a stupid question.

Geoff

I am a retired electronics engineer, so making up leads is easy to me.

The 18AWG cable has good current capacity for most astro equipment needs.

The other thing to consider is volts-drop along the cable. Some of the Skywatcher equipment (particularly Synscan handsets) is sensitive to lowered voltages at its end of the lead chain. This is where the lead lengh, and its related resistance, is important. The table that I looked at, showed 18AWG resistance as 20.9 ohms for 1000 metres. That equates to a volts drop (with supply and return wires, and the 3.5A mentioned above) of about 0.15V per meter of cable length. If you assume 10 milliohms contact resistance for each (clean) connection in your connectors at each end of the lead, 4 * 0.01 *3.5 = 0.14V will be added to the drop, independent of lead length.

I think that, given a good 12V supply, most equipment that requires 12V will be OK with 1.5 metres of your 18AWG cable.

Geoff

3 days after my first picture (above) the Moon was further east, and the comet was much easier to spot.

On 28/02/2024 at 15:29, paulastro said:

It seems hard to find any sky conditions in which it won't surpass my expectations. 

Stellarium shows IC3602 as being magnitude (at this altitude) 15.68. OK no useful detail, but still impressive for an extremely "faint fuzzy". I'm also impressed with the sky map. It makes finding targets (including comets) very easy.

Once the Seestar has identified and centred the session's first target, it slews to take 3 orientation images to plate solve for mount leveling error correction. The mount goes back to the target, and goes through a (roughly) 1-minute process. The on-screen information does not explain why. I am assuming that it is recording a few "Dark" frames to use in its stacking process. If I am correct, it would be nice to have these made available for future post-processing.

Geoff

5 minutes ago, Flame Nebula said:

Have you ever compared it to a C9.25?

No. I have the, much smaller,  Skymax 127 MCT, and this is faster to set up than the bigger Dob., but does not gather as much light if I am going for faint fuzzies.

Geoff

2 hours ago, Flame Nebula said:

How would you rate the scope's visual performance? 

I'm no expert, but it works well for me, with a range of eyepieces and a comfortable viewing position range. I do not normally have to adjust the collimation each time I extend it - perhaps a minor adjustment of the primary mirror, a couple of times a year.

Geoff

11 hours ago, paulastro said:

Do you use a lens hood?   I do and I have had no problems with reflections.

Yes, my thoughts too; when I saw the effect of the build-up of moonlight, I thought it was worth a try.

I have started to make one, from a short section of kitchen roll cardboard inner tube (it was hard to find one that was a snug fit in the Seestar's lens aperture), and a square collar (to stop it rolling around, and keep the tube circular). The next step is the matt black paint.

If it works I will probably make a spare, just in case I forget it is fitted and power-down.😧

I'm a fan of GoTo, and its associated ability to track whilst I change eyepieces.

When it starts to get dark, I can set up my Skywatcher Skyliner 250 flextube Dob. with Synscan Goto, using Brightest Star (2-star, or planet + 2-star); then go in for tea, and the 'scope will still be tracking the last alignment star when I come out refreshed. I can still direct the mount manually, and the encoders tell the handset where the OTA is pointing, so I have not lost alignment. However, I find that it is much easier to use the handset, with its range of slew rates available, to slew quickly and then make fine adjustments to centre the target.

Geoff

1 hour ago, paulastro said:

It just seems like that because you get more used to how good it is the more you use it.  It seems hard to find any sky conditions in which it won't surpass my expectations.  I've learned that the bright Moon is not an issue.

I agree almost 100%. I have found that if the target is close to the almost-full Moon (comet 62P a couple of nights ago) I was getting some reflection from the Seestar's plastic causing a brightening of the image on the opposite side to the Moon. The Moon was below-left about 12 degrees away. If you look closely, you can just make out the comet.

A month earlier, much better:-

Geoff

Last night, Comet 62P was too close to the almost-full Moon, and with light cloud, almost washed out

However, Stellarium led me to the Eskimo Nebula - small but interesting

I also like the way the "Mark" function tries to shield you from adjacent bright objects

Geoff

And from North Somerset, Uranus direct from my Seestar, without post processing,

3 moons just visible, Titania (top centre), Oberon (top right), & Umbriel (bottom right)

And comet 144P / Kushida (below right of HIP 25278 (111 Tau) [the big, bright one]

Geoff

This evening, direct from my Seestar, without any post-processing.

Geoff

If I think that I am going to have a long session, I use a little power bank for mobile phones/tablets. I bought it fron "The Range" about a year ago for £14.99. It has 5V 2A and 5V 1A, USB A outputs, and a 5V 2A micro-USB input. It is rated at 20,000 mAH (probably @ battery voltage of 3,7V), so 10Ah @ 5v would be more realistic. It should easily double the length of a session. A quick google shows similar devices, although prices seem to have risen somewhat.

Pages 44 & 45 of this topic (Jan 13th onwards) discuss the charging of the S50 and its use of external power at low ambient temperatures.

Geoff

4 hours ago, GasGiant said:

Specifically, anyone using Samsung tablets ?

Yes, but The Seestar requires Android V8, or later, and my (old) Samsung Galaxy Tab S2 runs Android V7, so it will not even load the Seestar app. It will run the Dwarf II app, but that, I believe, works with V5 onwards. I now have a Blackview Tab 60, running Android V13, and that works well with both 'scopes.

Geoff