Zakalwe

2 hours ago, ollypenrice said:

 How can this correct vignetting if the chip is sampling a smaller or larger diameter light cone?

Vignetting isn't really the problem here, it's uneven lighting across the whole image.

The way I do it is to centre the image on the disc so the whole field is illuminated. Then either use a bit of clingfilm across the aperture and defocus, or just defocus without any film (depends if there is cloud cover or not). Dunno if it the correct way, but I know that it seems to work for me.

13 hours ago, Mark_C said:

That's incredible! Very sharp and detailed. It's impressive how excellent results can be achieved even when you have to fight against challenging equipment, well done!

Thank you.

I wouldn't really describe it as fighting against challenging kit, more it's just a necessary step in the overall process. Achieving sharp focus and trying to beat the seeing (I use a 120mm Espit refractor with the Quark) are much, much more difficult than spending 2 minutes taking some flats.

6 hours ago, Mark_C said:

Oh wow, that really is rather bad! How does your images look once the flat has been subtracted?

I've had my moments.....

Nothing wrong with that Quark at all IMHO. I wish that mine was that flat!

Solar flats are an essential piece of the imaging workflow and are very easy to create- either stretch some clingfilm over the aperture or de-focus the heck out of the image.

For example, here's a flat from one of my Quarks....and this is after correction with a tilt adapter to get rid of the Newton's Rings. You'd have a conniption if you saw the image without the tilt adapter!

Get shot of the tripod and tube. Carbon fibre is very rigid *along the strands of the fibres* but can be flexible in other axis. You also need mass to damp down the vibrations. That tube, mount and counterweights represent a heck of a lot of mass and surface area, all mounted on a tipod.

I would wager that a decent steel or concrete pier will get rid of a lot of your problems. You could try hanging a substantial weight directly underneath the tripod, suspended off the ground to see if more mass will help with the damping.

Have at it then. Though, once you take the central obstruction into place, a 6" SCT probably wont get that much more resolution than say a 5" 'frac. 

Works fine on mine.

On 12/04/2023 at 06:13, CharlesS said:

Thanks, Peter. I have seen some great results with both 9.25 and 11-inch SCTs, in both WL and Ha. So I am going to take a chance on the 6-inch. It is a little more complicated for Ha, but still doable.

For H-A, a  6" ERF (essential component) costs approx £1K. More for one with a mounting bracket. Then you will need an etalon and various blocking filters. You will end up with a highly specialised system that will need a lot of knowledge to use and will require superb seeing conditions. I'd recommend starting off with a dedicated H-A scope first.
https://www.widescreen-centre.co.uk/baader-d-erf-energy-rejection-filters.html
https://www.altairastro.com/altair-152mm-aperture-triband-d-erf-solar-energy-rejection-filter---h-alpha-plus-cak-cah-160mm-erf-11920-p.asp

With H-A viewing (or imaging) the actual scope is probably the cheapest component of the whole system. I suspect that you may be putting the cart before the horse.

For WL viewing, then a sheet of Baader Astro Film and a continuum filter is what you need.

https://www.firstlightoptics.com/solar-filters/baader-astrosolar-safety-film-nd-50.html

Quark Chromosphere on Esprit 120

Stacked in AS!2, sharpened in IMPPG, finished in PS CS5

Thanks for looking ☺️

https://astrob.in/full/fo60g6/0/?real=

https://astrob.in/kxdzzq/0/

The pixel size on the 174 is a bit too large for the 80mm, although it works extremely well with setups using a longer focal length (such as when using a Quark). Perhaps one with smaller pixel will work better. I pair an ASI 178MM with my Lunt L60 and it does nicely.

3 hours ago, Astroscot2 said:

Lovely image Stephen.. do you still image with the Quark?

I've had a busy couple of years with a house move and life in general. Although I rebuilt my obsy, what builders pass for a lawn meant that using it wasn't really an option in wet weather. So this is sorta a first light.

Yes, still got the Quark. Got some data to process, once I remember how!

https://astrob.in/5sje1s/0/

[URL=https://astrob.in/5sje1s/0/][IMG]https://astrob.in/5sje1s/0/rawthumb/regular/get.jpg?insecure[/IMG][/URL]

19 hours ago, Astroscot2 said:

Hello Stephen.  good to see you back, are you still imaging with the Esprit?

 

Mark

Hi Mark,

Thanks for the comment. I moved house almost exactly 12 months ago, so still haven't got the observatory back up and running, though I did finally manage to get a solarscope out the other day.

With a bit of luck and focus I should be back in action soon. And yes, I still have the Esprit 120 ;-)

On 30/07/2022 at 16:00, newbie alert said:

Does that mean that it doesn't work? I've not read any negatives from mesu owners.. only ever positives... 

 

You should extend your reading horizons then. There's a very long thread on here detailing serious issues that I and others have had with this system. The resolution took many months to sort out and only with the persistence of the users and Dan Gray's exceptional help. The experience pretty much killed my enthusiasm for this hobby for a number of years.

An easy way to measure drift is to run the PHD Guiding Assistant. Let it run for at least 5 minutes (longer is better) and it will tell you the actual drift.

1 hour ago, Jonk said:

Also, balance the DEC in all directions before adding counterweights to balance in RA. Otherwise, RA will never be balanced properly.

Be very careful doing this, especially if there is a big load on the scope. There's a very real danger of the telescope swinging round and smashing against the pier/ your head with real force if you load it up without counterweights. You could also deal yourself a serious crushing injury if a hand or arm came between 40Kg of scopes and the pier.

On 29/03/2021 at 08:27, Laurin Dave said:

I haven’t used it ..  only found out recently when after 27 months of ownership I decided it was time I read the manual...  and yes a useful tool..  I have my Dad’s AVO, older than me still going strong 💪 and immensely useful 

I found that it changes too rapidly to be of any use. The Mark 1 Mesu is best balanced by good old pushing and pulling. The mechanism is quite stiff so it's only ever going to be an approximation but it seems to work fine.

Balancing on the Mark 2 is probably a lot easier.

Pay a bit more and get a regulated power supply. Personally I'm leery of using those cheap eBay PSUs (often badged as CCTV supplies). They need casing and they aren't designed to be used in condensing environments. They have the potential (geddit?) to have exposed contacts at mains voltage. One slip-up with a finger in the dark and you could be found dead the next morning. How many times have we tripped or banged our heads in the dark?

Also get a decent Anderson powerpole  splitter and convert all your gear to Anderson plugs. it#s well worth investing in a proper Anderson crimper too.  The Anderson plugs are handed so they cant be plugged in the wrong way and are very solid, unlike crummy cigarette plugs.

Anderson PowerPole splitter

Hi  Torben,

I have had a similar experience, so I understand your frustration.

A couple of things....RA drift can be solved pretty easily. If you use PHD V2 then you can use the Guiding Assistant to accurately measure the drift amount. You can then calculate the change that you need to enter in the SciTech config tool. See this post on how to calculate the amount that you need to add or subtract in the Tick field to correct the drift:

Quote

I previously had problems with my RA guide speed being too slow and as a result PHD was correcting RA always in the same direction and could not guide efficiently.

I decided to use Artemis (my ccd capture software) to track a star for 10 minutes and determine how many pixels it moved .

I made sure that my RA axis corresponded with the up and down lines of my cross-hair in Artemis and then slewed a star to the middle of the cross-hair.

I then placed my mouse pointer on the middle of the star and read the pixel number shown at the bottom right of the Artemis software window (for RA the pixel number is the second one)

After 10 minutes I placed the mouse pointer on the middle of the star again and jotted down the new pixel number.

I subtracted the first number from the second.

In my case the star moved up and moved 91 pixels.

I then multiplied 91 x 1.11 (the pixel scale of Atik 383 and Quattro 10")

This gave me 102 Arc-seconds of movement in 10 minutes.

Lucas Mesu Kindly helped me out with the next bit and I eventually managed to understand the Maths.

I launched Servo Config and  clicked " Edit Parameters" to get the data from my controller.

My number of ticks per scope revolution in the Ra Motor was 7949474.

In 10 minutes the Ra makes 9000 Arc seconds.

This is the Maths as explained by Lucas:

In 10 minutes the Ra makes 9000 Arc seconds.

Divide the error (102) by 9000=0.0113333333333333

0.0113333333333333 x 7949474=90094

7949474 - 90094 = 7859380

7859380 is the new number to put in the Ra Ticks per scope Rev window in servo config.

In my case this made it worse so instead of subtracting 90094 from my original ticks per revolution of 7949474, I added it to obtain my corrected number of 8039568.

Now my mount is tracking efficiently in Ra too and my guiding problems have been sorted too.

If you use the PHD Guiding Assistant then it will take the first couple of steps out as it will give you the drift amount that it is out by.

Regarding the handset- contact SciTech directly. They did have a bad batch of handsets so you *might* have one of those. I had one replaced by Dan at Scitech- no questions asked and they paid for shipping and the handst. They are a great bunch of guys to deal with....nothing is too much hassle for them.

Fingers crossed that you get it sorted.

On 06/07/2020 at 14:09, R26 oldtimer said:

Is there a reason to think that your thread might be more interesting than the rest, as to need a bump?

A YouTube channel that wants more subscribers?  

Dont forget that any filters that are in the light train may also increas or decrease the spacing The best thing to do is get it as close to the manufacturer's specifications and then then test it. It can happen that you need to move it a bit to get the best results (or maybe accept a certain amount of cropping).

Wait until you try fitting an OAG and a filter wheel in there, and then wrestle with getting the guide camera in focus at the same time as the imaging camera. Stiff drinks may my required at this point! 😆

On 21/07/2020 at 09:02, Neil27 said:

My 2 cents, if your thinking of dropping 3k down for a mount I would seriously consider friction drive, either Gemini, JTW or Mesu (S/H). Zero backlash and the quality may be slightly higher, reflected in the slightly higher price.

Slightly higher?

A Mesu mount is almost exactly double the price. They rarely appear second hand, though there might be a few popping up in the next 6 months as the forthcoming recession takes effect.

The Gemini is 30% more expensive and that excludes the controllers and shipping

The JTW mount is €4100, VAT excluded, so add another 20% on top. And that's assuming that the thing is even shipping.

That's a long way from "slightly higher"!

Now we all know that you're not a self-respecting imager until you have a drawer-full of stupidly expensive adapters/tubes/doo-hickeys. The one that you need for the task at hand will naturally be cold-welded onto something else and no amount of swearing at, threatening, brute force, strap wrenches, heating or cooling will separate. 😡 Naturally, you will be forced to buy another over-priced bit of aluminium and delay the job until it arrives.

To prevent this, try this stuff:

https://www.amazon.co.uk/gp/product/B00BTOBHH6/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

Its normally used by locksmiths to free up sticky locks. Yes, you can rub a pencil on the threads, but if your house is anything like mine, pens and pencils seem to magically disappear.

I've heard of other solutions- shoe polish, being one, or anti-seize compound. I personally don't like the idea of wet or volatile lubricants being used near optical surfaces in case they creep or off-gas. Too much chance of getting them on fingers and transferring them somewhere that they shouldn't be. The beauty of graphite powder is that it is dry and if any gets on an optical surface then a puff from a blower bulb will soon dispatch it. And, at less than a fiver for a bottle that will last decades, it'll probably be cheaper than buying pencils.

Recommended.

Youight be exceeding the total number of hubs allowable?

Personally I think it's down to cable length. Active cables can be glitchy. Either shorten the cable to the laptop or investigate USB3 over Ethernet.

I use Orico hubs and they seem to work. Even so, I found that some cables would just not work over a longer length. I guess it might depend on the quality of the conductors and what not.