MARS1960

I have just been checking the image train and decided to focus on a distant branch. 
when I turn (fine or coarse) to focus the branch moves up and down by about 10mm across the LCD screen. 
will this focus shift be causing my issues? See attached video.

TIA. 

IMG_0476.MOV

2 minutes ago, Uranium235 said:

Looks consistent with tilt.

A fully loaded imaging train acts as a lever under gravity. So any movement in the focuser or imaging train would be exposed.

But, I take CCD inspector with a pinch of salt. You would need to take multiple shots of different parts of the sky (but not go past the meridian) to see if the readings are consistent.

Drat, I'm not sure what to do then Rob.

I have pushed, pulled, wiggled and wobbled and this gear is so snug all three parts of it act as a single unit without even whisker of movement.

Thanks for your help.

10 minutes ago, Uranium235 said:

DIfficult to see since you havent poseted a full screen shot. But from what I can see it is tilted to one side a little.

Even my Star 71 needed its focuser (which was also R&P) tweaking out of the box, there are two bolts on top of the focuser- you may need to nip those up a little (and I mean little).

You can check for focuser movenent by racking it out a bit - then basically give it a tug in all directions. If you detect any movement/wobble (no matter how small), then it needs to be tightened up.

Still needs to be in focus though to make the correct assessment, before you do any adjustments.

Ok thanks Rob, I'll check that now.  So those numbers look ok?

More images.

5 minutes ago, Uranium235 said:

You only need to adiust the flattener if you have introduced a filter into the imaging train or had the camera modified (filter removed).

Making the spacing longer will only make it worse, it needs to be shorter. Or in focus. The spacing as detailed by FLO is 11.4mm, however that is the recommended distance, and not every camera/filter combination is the same, so you may need to tweak that by a mm or 2.

But, only from a properly (centrally) focused image can you make a proper assessment and decide which way to go (longer or shorter).

When focusing, zoom right in to the diffraction pattern... not on the camera screen but using either EOS tools or something like APT. Then, after 45 min or an hour... do it again. (especially during cold weather).

 

Thanks Rob,

I think you might be looking at a different FR, I know the one that says 11.4, (73A, mine is 73R) this is mine: https://www.firstlightoptics.com/reducersflatteners/william-optics-x08-adjustable-reducer-flattener-for-zs73.html

I also did CCD inspector, attached image image but not sure how to read it, good, bad?

Thanks.

1 minute ago, Uranium235 said:

Ok, looking at that image... it is out of focus, but it does display corner characteristics (the distortion is of equal magnitude in all corners) that tell you either:

1) The FF/FR spacing is too long

or

2) The optics cannot provide a (perfectly) flat field across APS-C or larger.

 

But, get the image in proper focus first - that might correct a lot of the issues.

Thanks Rob,

The 73R was apparently built with DSLR's in mind, so according to FLO website no spacing is needed (It gives the 56.8mm needed) BUT, I did just notice that I also need to move the adjuster out by 1.8mm which I have now done, maybe this will fix the issue?

Not sure what happened with focus as I used the built in mask, possibly it shifted when I locked off.

I'm hoping any tracking errors will sort themselves with more use.

I'll be guiding next time too, I didn't do it last night as I didn't need the extra hassle just to check the scope and mount.

I've just read about CCD inspector, I will download that too.

Thanks.

5 minutes ago, Uranium235 said:

Looks like tilt in the imaging train, being as it gets progressively worse from left to right. However, there is a tracking error in there too.

1) Check for saggy or loose connections.

2) Take shorter subs to get an image free from tracking issues (or get guiding) - that will allow you to correctly judge where the tilt is.

3) Inspect the corners of the test sub, make adjustment as required

4) Rinse and repeat until satifsied

Thanks Rob,

After zooming in and seeing seagulls I was worried it might be the scope.

Everything was very tight as the FF screws directly to the scope and I used a quality WO M48 DSLR adapter which gives a super snug fit.

How would I cure tilt in the imaging train? I don't even know what that means :).

5 sec sub attached.

Hi all,

First light with my new Ioptron CEM26 and WO ZS73  with WO 73R x0.8 FF/FR with APC-S Canon 60D.

I levelled the mount, balanced everything up and did a "perfect" pole alignment with Ipolar.

This is a 120sec unguided sub but something is very wrong on the right hand side, any help would be greatly appreciated.

53 minutes ago, Alan White said:

That looks super Mark, the tripod looks a very solid one, be interested how it performs.

It really did surpass my expectations Alan.

When I got it out of the box I couldn't believe how well made, strong and sturdy it was for such a light tripod.

Compared to my other two tripods this one just oozes quality, I'm very impressed.

Last week I posted up the arrival of my new WO ZS73 II. 
Today my Ioptron CEM26 arrived. 
I opted for the literoc 1.75” and Ipolar. 
I am well chuffed with this mount and tripod, even has its own built in anti vibration pads and is very well made and pretty sturdy. 
The mount looks rather unusual compared with my previous CGEM and HEQ5. But it certainly looks very well put together, it’s very smooth and very quiet. 
Just waiting for the arrival of a clear night now. 
 

My contribution thanks to those lovely peeps at FLO. 
And of course William Optics. 

This is the most beautiful, wonderfully engineered scope I have owned and I’m chuffed to bits with it. 
I decided on the 73R x0.8 F/R and the ASI 120MC-S I had already purchased for moon/planets will double up as guide cam. 
Oooh and yep, it came with snow. :).
 

Most likely an old SW EQ5 or CG5, William optics don't make mounts.

I suppose you could ask dedicated wildlife photographers why they sit in (sometimes) cold cramped conditions for weeks on end tracking some animal or another!

I sold up about 18 months ago but have just bought some new gear, I just could not live without the challenge of "getting that shot".

I will never forget the excitement when I first saw M42 on my DSLR screen i ran into the house shouting at the wifey, "I GOT IT, I GOT IT, LOOK, LOOK, that for me makes all the waiting, all the frustration when things aren't going right and a multitude of other niggles very, very much worthwhile.

48 minutes ago, michael.h.f.wilkinson said:

I personally almost always use my flattener/reducer (0.8x) with my APM 80 mm F/6. Imaging at F/4.8 really helps, and the field is nice and flat. On the rare occasions I don't use the reducer, I do insert the 1x flattener I got with the scope.

41 minutes ago, vindubs said:

I have the 73II and use the 73R excellent bit of kit! If you gong to use DSLR then a must. 

Thanks to you both guys, I almost changed my mind and went with 1.1 Flattener, but it sounds like you both agree the 0.8 FR/FF is better and that faster f ratio really appeals.

That is a gorgeous image, I do love the bright colourful ones and you have done an excellent job 👍.

Hi guys,

In my basket is the below.

I will be using a crop sensor camera (Canon 60D) to image and a ZWO ASI 120 to guide.

1st question: Can I get away with not buying the FF/FR? if so how much will I need to crop a large object? or should I just get it anyway for a faster f ratio and guaranteed flat field.

The "wish I'd bought it now" feeling later when I've wasted a very rare clear night is not something I need lol.

2nd question: Am I forgetting anything?

Thanks.

William Optics x0.8 Adjustable Reducer Flattener for ZS73Model: wo-flattener-ZS73R7x in stock shipped 1-2 working days

£219.00

William Optics 50mm Slide-base Uniguide scope with 1.25" Rotolock

Model: wo_50mm_uniguide_slide_base_red4x in stock shipped 1-2 working days

£125.00

William Optics Zenithstar 73 II APO 2019

Model: wo_zs73_rd4x in stock shipped 1-2 working days

£549.00

William Optics DSLR-M48 Ring Adapter

Model: wo_m48_adapter_canon_black7x in stock shipped 1-2 working days

£25.00

Thanks for your help Pierre.

52 minutes ago, Toaster05 said:

Yeah, almost all the available cameras on eBay tend to be sold as the 18-55mm kit. I fully expect to have to change lens but as you correctly alluded to, I'm green so it'll be fine to learn with.

I'll be able to photograph the moon I'm sure at least!

If you type the camera of your interest into ebay ( IE: canon 60d body only) and check the sold filter it will list only body only ones (well 99% anyway).

I'd still recommend the 60D, I have used it extensively for terrestrial and astro for years and you have the bonus of choosing cheap older lenses that match the slightly older 60D body, lenses like the 18-135mm are a great lens and very useful.

3 minutes ago, Space Oddities said:

There is also a reducer/flattener from William Optics for the ZS73: https://www.firstlightoptics.com/reducersflatteners/william-optics-x08-adjustable-reducer-flattener-for-zs73.html

It's a bit more expensive, but I don't think you can go wrong with it, as it's designed specifically for this scope. Perhaps that optically it's the same as some other reducers, but at least mechanically, it seems unique to WO.

The StellaMira is a generic flattener, you can find many brands selling it and recommending it for similar 70-72mm scopes. So, like all generic products, there's a small risk that it isn't a perfect fit for your scope.

Thanks for the reply.

I'm basically trying to save money, The Stellamira even comes with (needed for me) the M48 DSLR adapter saving an extra £25 on top of the £70 for the WO one or even £120 over the one you mention.

The Stellarmira is definitely a perfect fit, my concern is will the reduction to f4.72 cause any imaging issues with an APS-C regards artefacts etc? I wont be submitting images, It's purely for my own entertainment.

Thanks.

I have not owned this mount but it does pose an interesting question.

Hopefully this may help you decide.

https://starlighthunter.com/articles/az-gti-equatorial-mode/

I hope you guys can help me out and save me from making more expensive mistakes.

FLO finally have what I have been waiting for (WO ZS 73 II) but I now have a dilemma.

Do I really need to spend an extra £26 on the larger guide scope, or will the little £99 one do the job just as well for my amateur backyard occasional AP?

https://www.firstlightoptics.com/william-optics/william-optics-50mm-slide-base-uniguide-scope-with-125-rotolock.html

https://www.firstlightoptics.com/guide-cameras/william-optics-32mm-slide-base-uniguide-scope.html

Do I have to buy the 1.1 Flattener, or can I save some more and buy the Stellamira 0.8 reducer/flattener for a slightly faster f ratio? will it cause any issues if I can? I just don't want to make any mistakes this time round.

https://www.firstlightoptics.com/reducersflatteners/william-optics-adjustable-flattener-for-zs73.html

https://www.firstlightoptics.com/stellamira-telescopes/stellamira-2-0-8x-reducer-field-flattener-with-m48-adapter.html

Any help greatly appreciated.

Type it into ebay and use the filter for sold items only.

But my advice would be to spend around £300 and get a decent 60D, it is one of only three Canon cameras that has a dedicated 640x480 crop mode, this is great for the moon and planets. 

3 minutes ago, Stu Wilson said:

you gotta link so I can look?

 

It's on a mount but that's easily sold at the moment. A few SW fracs there too, ED80, ED120.

https://www.ebay.co.uk/itm/TS-Optics-6-Refractor-Telescope-F6-5/174590594853?hash=item28a6690f25:g:J2QAAOSwCIJf-xoJ

I'm looking at fracs, there's a TS optics 6" frac on ebay now, too big for me but great for your use.

3 minutes ago, Taman said:

I think FLO may have what you're looking for? You'd have to check they're compatible.

 https://www.firstlightoptics.com/search/for/dovetail spacers/ 

Tony.

Thanks Tony.

They look perfect, I'll drop them an email, if all is good I think it's decision made.

1 minute ago, Taman said:

Thanks Mark!

I've not even thought about locking the focus as it stays where it's put! I don't have that problem, as I bought it to piggy-back on the SCT and have a small counterweight at the top end of the Celestron tube.

Tony.

Thanks Tony.

I'm sure a simple solution for me would be to find a couple of risers like Altair Astro did with their 72 EDF.

Or just buy the 72 EDF lol.