Cosmic Geoff

Planetary imaging does not require the ultimate in mount stability.  It's nice if the mount does not jitter about when you are trying to focus, but the planetary images I took with a Celestron SE 6/8 mount were often just as good as those taken with a CPC800.

1 hour ago, Louis D said:

So, do you then need to add a field derotator to image using one?  I didn't see one in the image above.  Is it done in software?  That is, derotating many short images during stacking?  Does that work well with DSO imaging? Thanks!

Live stacking or post-stacking of a series of short exposures can work well with alt-azimuth mounts.  See the results from the Seestar S50, for instance.  Of course, the extremities of the image degrade with longer exposure runs, but can be cropped off.  It depends what one is trying to image.  If gathering hours of data on something faint, an equatorial mount would be more appropriate.

There are two questions you should ask when looking at a light pollution filter:

1) What kind of light pollution do I have in my area? Sodium or mercury lamps? LEDs? Other?

2) What exactly does this filter do? What wavelengths does it pass? or block? 

If you have a diffraction grating or prism to play with, you can actually see what is being emitted by local lights.

Getting the images from the Seestar to a PC is a no-brainer - just use the USB cable supplied and Windows Explorer.  That's assuming you set the Seestar to store separate images rather than stacked.

Most of the 'how to' videos involve using Siril, which is a powerful program but almost impossible to use without detailed instructions. I found it easier to do the initial stacking in Deep Sky Stacker.  TBH I have only tried to 'improve' the images where the smartphone image had airplane tracks or was not saved at all.

You will have to look on this forum in the Seestar thread for general tips, and on Youtube for processing videos, as the ZWO manuals do not tell you much besides how to turn it on. ☹️

Why do you want to extend the OTA about 50mm further forward? Are you attaching bulky gear to the back end of the OTA?  I had obstruction with my CPC800  when attaching focal reducer + flip mirror diagonal + camera.  A solution was to dispense with the flip mirror and use a regular diagonal and precise GoTo.

If it's the same clamp as on the C8 SE, the OTA will not go any further forward unless you also move it sideways.

10 hours ago, vansky said:

Okay thats good to know about the adaptor on the scope. After I wrote my post above I looked at the Skymax 180 specs, which is the compound scope I am thinking I'll get once I get comfortable with the whole astronomy/AP thing on my ZenithStar, and its 2" so maybe I'll just get all my stuff at 2" so I can use the eye pieces on either one, though i'll check price differences between the 1.25's and the 2's.

What do you mean by a 'compound scope'?

  The point about 2" eyepieces is that if you want a low-power eyepiece with a wide field of view, e.g. 30mm fl, the resulting size of the lenses means it won't fit into the 1.25" format, hence 2".   But a 10mm eyepiece will fit easily into the 1.25" format, so there is no point in making a 2" version.  2" eyepieces are generally heavier and more expensive.    Adapters that fit a 1.25" eyepiece into a 2" focuser are readily available.

I found that the GoTo of the 6/8 SE mount works well.

I keep mine indoors fully assembled and with the tube horizontal.  I don't think it matters where the tube points, but horizontal is the starting point for the Starsense Autoalign. 

Note that because of its bulk which makes it awkward to grip and handle, removing the tube from the mount is not a clever idea.

I have been carrying mine in and out fully assembled for years and it has not done it any harm.

If you are not able to handle one of these scopes in the metal before buying, you could find some cardboard and a couple of bricks to make up a dummy of the same length x width x height  + weight, and see how you feel about carrying it downstairs and onto  a bus. 🙂

No need to deploy fresh hardware. There are many present and past sky surveys, e.g. PanSTARRS and Gaia.  Anyone looking for anomalous objects could trawl through the vast amount of data already accumulated.

I agree with the revisionist view that Pluto is a minor planet.  I have managed to image and identify it a couple of times.

+1 for a Seestar.  It will work well for imaging emission nebulae even in a city, giving you far better views than you could hope to get visually.  It will also work on other DSO's, especially if you can take it to a darker site, which would be easy to do, since it is small, very portable, and comes in a carry case.

Be aware that galaxies will be a disappointment visually, and barely visible unless you have a scope of significant aperture at a dark skies site.  All I can see of galaxies from my urban location is a grey smudge representing the central nucleus of a few of the brightest ones.  But if I use EVAA (q.v.) it's a different story.🙂

I suggest that you look at the threads on this site and elsewhere to see what the Seestar and other smart scopes achieve in practice.  The Seestar can stack for a surprisingly long time without field rotation becoming an issue.  And one user claims to have figured out how to make it perform in equatorial mode. 

For smart scopes in general, the main thing to look at is the achieved field of view.  The Seestar, for instance, uses a small sensor, so the field of view is smaller than it potentially could be (but the Moon still fits in the FOV).  If you want planetary imaging, look elsewhere, as you will only get impressive planetary images with a long focal length and large aperture.

Note that the less popular models may have software & firmware that is not as polished as with some others. Read the reviews.

Some of the smartscopes seem quite expensive.  The test here is how much would it cost to put together a rig with the same performance, using separately bought parts (i.e a traditional imaging rig).   Some smartscopes might fail this test, but  the Seestar can only be beaten by spending far more than its £550 asking price, which is why it has proved so popular. 

There are a number of smart telescopes on the market now, ranging from ZWO's Seestar S50, which appears to be wildly outselling all the others, to Celestron's £4000 6 inch aperture offering.  What attracts you to the two you have mentioned?

What are you expecting a smart scope to do for you?

Nowadays we use CMOS cameras, not CCD.

What do you want to image and what is the budget? This will determine what cameras we suggest.

34 minutes ago, DavB said:

Any ideas what on earth could be going on??

A power supply problem? Try fitting a proper +12v regulated power supply or power pack.  If you are using 2 year old internal AA batteries I'm not surprised it doesn't work. 

2 hours ago, phil18 said:

What about astrophotography?

Serious astrophotography will need a more accurate polar alignment, together with tracking and autoguiding.  But try with your kit and see what you can achieve.

The tripod used with the C8 SE has a similar top - I have both and I did compare them a while ago. Same spacing for the 3x holding screws but the center pins are not identical.  To be frank though I think this is a bad idea - the C9.25 Evolution will really need the heavy duty tripod.  If you put it on a lighter tripod I expect it will be waving in the breeze.

If you have suitable access, putting the whole assembly on wheels might be a better option.

There will be some resistance to turning the gear.  The gap between the worm and wormwheel should be adjusted to minimise backlash without making it too tight, lest the worm rotation bind.

There is no way the bearings will have worn enough to need replacing.   The plain bearings in my old car engine lasted for billions of revolutions.

You do not say what kind of motors (if any) are currently fitted to your EQ-3.  If it's motorised, there should be a speed adjustment or a choice of sidereal/lunar/solar rates. How good is your polar alignment?

You still have slight trailing at 1 second exposure. Maybe it's not tracking at all? I have regularly made exposures of 20 seconds (tracked but unguided) without noticeable trailing. 

13 hours ago, janemc40 said:

i was looking at this scope if anyone knows about it and has a review 

I have this scope (the C8 SE).  There should be lots of reviews online if you look. A fine scope for visual use, and easy to move around as a unit.  With the SE mount, not much good for imaging, except maybe planetary imaging.

The message basically means that the mount is not responding. That could be for various reasons.  A similar message from a Celestron Nexstar typically means that the mount firmware needs a refresh, or water has got into the mount electronics.  Solution: reload the firmware, or open the mount and dry it out.

On 15/01/2024 at 08:00, powerlord said:

So, this chap says he has it working in EQ mode. He says since latest firmware it does 3 star calibration.

Since the latest upgrade, it does spend a couple of minutes doing something called horizon adjustment (whatever the heck that is) unless it is turned off in the settings.

A 150p should easily show something of Saturn's rings, even with the kit eyepieces. You will have to be quick before it disappears into the twilight.

Viewing the Great Red Spot will require a good quality eyepiece of suitable focal length, plus keen eyesight. 

If you received  Barlow lens with the Startravel, try using that + an eyepiece for planetary viewing.  With my Startravel 102, this appeared to decrease the chromatic aberration on planetary viewing.  If it doesn't work for you, nothing lost.

My Startravel 102 works well as an imaging scope for EVAA (you may need a more serious mount).  One can anticipate that a dual-band filter for imaging nebulae will also cut much of the chromatic aberration.

You should figure out how fast it is moving.  If it doesn't trail on a stacked image you will need to image it twice a suitable time apart. There will be a lot of stars in the image at around mag. 19 and you have to figure out which dot is 3922.