Ricochet

32 minutes ago, Aston said:

I took a picture down the eyepiece holder, is it possible to say from that weather the scope is collimated correctly or not?

 

Its difficult to assess as you really need to take the photo through a Cheshire or collimation cap to make sure the camera is properly centred, however I would say that the photo you have posted does look out. 

The first thing that I would do is to check the collimation using a Cheshire. I'm not really a fan of lasers and generally speaking think a Cheshire will give an more reliable result. 

When it comes to poor images most problems are usually due to atmospheric thermals. The first and most important are those in the scope itself so make sure that you give it a good amounting time to cool. I would suggest at least an hour as you are trying to assess the image quality. 

Secondly, be careful about what you are looking over when you observe. Man made structures (buildings, roads) tend to hold and release heat much later into the night than fields and forests. If possible try to avoid observing over houses. Even waiting for an object to pass over the gap between two houses can have a dramatic difference if you're in an urban location. 

The amount of atmosphere you look through will also have a big effect, and larger telescopes suffer more from this than smaller ones. Observing an object when it is at its highest will minimise the amount of atmosphere you are looking through and hopefully improve the views. 

Beyond that, I would advise trying to contact your local astronomy group and see if there is any possibility that one of their experienced members could have a look at your scope and give their opinion. 

You can use just the Cheshire for all steps of collimation, which will save on costs. However, I would advise spending your money on a good quality device rather than a cheap one, either the FLO premium Cheshire or a concentre would be my choices. 

41 minutes ago, PaulSea64132559 said:

The first day of setting it up i accidently dropped it and the mirror at the back came loose

Usually the mirror cell is fixed to the tube via screws and should not just come loose. It would probably be a good idea to post a photo or two of the rear of the scope so that we can see what damage has occurred. 

43 minutes ago, PaulSea64132559 said:

I managed to see jupiter last night but had a view like a big spider. 

 

This just means that you were out of focus and does not mean that there is anything wrong with the telescope. You just need to wind the focuser in or out to make the image as small as possible to focus it. 

2 hours ago, Craig a said:

As I don’t have access to a 3D printer I looked at ts service and you were correct I ordered one from there for my 130pds should be here in a few days 

Excellent. Let us know how you get on with it. 

For monoviewing I'd go for a 7XW. You might not "need" it for planetary, but the 70° field is a bit of a sweet spot. 

2 minutes ago, Craig a said:

Yes that helps loads thanks, I will have ago at making a mask too, is it critical to get the masks inner edge perfect? 

In my experience, I don't think so. Maybe carefully examining a photo you might be able to spot something but close enough is probably fine. If you want something really accurate I think I've seen commercial masks for Skywatcher scopes somewhere, Telescope Express perhaps.

2 minutes ago, vlaiv said:

Yet, field experience says that we can easily see some faint fuzzies in 8" but struggle to see them in 4". How come?

You've answered it in your question.

3 minutes ago, vlaiv said:

it will have twice as high magnification so galaxy will be double in size

Bigger things are easier to see. I can't give a direct quote/link but the idea that the brain picks out bigger things better than smaller things is a constant idea in texts on observational astronomy.

3 hours ago, Craig a said:

We’re not on the same wavelength here I don’t think I’m not on about the bright diffraction from the mirrors edge but the dark ghost pattern off the clips is what I want rid of 

Ok, perhaps a picture will help. Look at the image below.

• The left hand star shows what your stars currently look like, with both mirror edge diffraction spikes and clip shadows.
• The middle star shows what your stars will look like if you get rid of the clips.
• The right hand star shows what your stars will look like if you mask the mirror edge.

It's not the shadows that are the problem, it is all the excess spikes.

I'm a solely visual, but even then masking the mirror edge is the single best upgrade that I have made. It's also the cheapest, as my mask is just made from black card.

2 hours ago, Craig a said:

That’s what I mean the scatter/diffraction from the mirror clips causing the pattern on brighter stars, I’m not a fan of it and looking for a way of getting rid without making a mask to cover the whole perimeter of the primary covering the clips 

That is my point. The mirror clips are not causing the issue, they are preventing the issue at three points. If you take them off the problem becomes worse. 

2 hours ago, Craig a said:

Hi all I’ve seen people making masks to cover the mirror clips of Newtonians to eliminate the shadow they cast on brighter stars, but I’ve also seen people totally do away with them and silicone the mirror onto the mirror cell, I was thinking of doing the same to my 130pds using the silicone method to secure the mirror doing away with the clip. Has anybody done this to their 130pds and how secure is the mirror when the silicone is cured? Does this affect the mirror in any way? 

You don't mask the edge of the mirror to prevent shadows from the mirror clips. You mask the edge of the mirror to remove the scatter/diffraction spikes from the mirror edge. If you have shadows corresponding to the mirror clips, those shadows are the only places where you don't have a problem and you need to mask the rest of the edge. 

I'm sure Solarscope can help you. You want double stacked 100mm etalons, a blocking filter and a custom adaptor to fit the etalons to the front of your Tak.

https://solarscope.co.uk/filter-systems/

I've no idea how much that all costs though.

I think the Baader Morpheus would be a nice upgrade, but what is it about the Starguiders that you feel is lacking? What are you looking for from an upgrade eyepiece?

1 hour ago, Shimrod said:

Thanks for  the info - especially current lead times! I had misread the expected due date on FLO (60-90 days) but it sounds like that might be a bit optimistic if there are a lot of back-orders to fulfill once stock arrives. I can't see it in stock anywhere else. If I decide to go for the Maxbright it sounds like it won't be this season!

I think the 60-90 days might be the maximum option in the new expected due date system. If you do decide to go for the Maxbrights, I think you will be better off ordering them now to get in the queue rather than trying to wait for them to show as in stock and ending up further down the line.

I would go for the Maxbrights as I expect the optical quality to be better. Reflections are definitely something you want to avoid if using the binoviewers for observing bright objects like the sun, moon and planets. If you use them for DSOs the Orion/Bresser might be ok. I say 'expect' with regards to the maxbrights as the problem is availability. I ordered mine over a year ago and I still don't have any idea as to when they might be delivered. 

With regards to eyepieces BST Starguiders are extremely comfortable to use, but do show reflections with bright objects. The Baader classic orthos are a similar price and have better coatings, but are not as comfortable and have a smaller field of view. I have both 18mm BCO and 25mm Starguider pairs and would often find myself using the 25mm Starguiders over the BCOs due to the comfort level, but the reflections prevented me from buying a second 18mm Starguider. 

I agree with the above post. Starguiders would make a nice match for your scope. Even the long (18/25mm) focal lengths will be well corrected when paired with an f11 scope. 

Of the two I would go for the Helios, I am very happy with the performance of my 16x70s. However, 100mm binoculars will be very big and heavy and as such have quite substantial mounting requirements. At that stage I think a binoscope with interchangeable, angled eyepieces is going to be a better, but even more expensive option. 

8 hours ago, spaceslug said:

Interesting. I like the idea of a variable polarising filter, I've used one on my DSLR camera previously for standard terrestrial shots.  I may be about to challenge the "no daft question" comment though; if this filter fits on the inside base of a 1.25" eyepiece like other moon filters, how do you control the variability when it is attached to the telescope?

Thanks in adv.

Option 1: use two 1.25" filters on the bottom of the eyepiece, the lower of which is able to freely rotate. You have to remove the eyepiece to adjust the angle of the filters. 

Option 2: buy a 1.25-2" reducer that has 2" filter threads at the bottom of it, for instance I have the Baader Clicklock. You then put a 2" filter on the bottom of the reducer and a 1.25" filter on the bottom of the eyepiece. You can then adjust the filter by turning the eyepiece. If you do this with binoviewers you have to loosen off the clamp on the reducer and the clamp holding the reducer so that you can rotate the reducer as you cannot rotate the binoviewer. You also have to ensure that the barrel of anything you insert into the reducer does not protrude far enough to come into contact with the lower filter. 

However, I found that reflections created by a pair of polarising filters scrub detail from the image and so they no longer have a place in my eyepiece case. 

8 minutes ago, Maclean156 said:

It's a stupid question but what's star hopping?

Star hopping is a method of finding faint objects when you are using a manual telescope. You start by pointing your telescope at a bright star you can see, then "hop" from that star to a series of fainter stars you can see through the eyepiece or finder scope until you find the object you are looking for. Your 40mm could be used for this purpose. 

In my opinion the best option is to invest in binoviewers so that both eyes receive the same brightness. 

The best filter to buy is the Baader neodymium, but you can also get a good neodymium direct from china quite cheaply. 

Only removing the small cap will significantly reduce the resolution of your telescope and is not something I would do. 

At f10, most eyepieces will work well with your telescope, so you pretty much have a free choice. You don't have to match Celestron eyepieces with a Celestron scope either, as astronomical eyepieces are standardised (usually 1.25" or 2" fit). The 18mm X-Cel LX would be a good choice and pretty much split the difference of your existing eyepieces if you are happy with the 60° field, but wider fields of view are available if you would prefer a wider field. For example you could instead choose the 18mm Explore Scientific 82° eyepiece, although this is a 2" eyepiece and would therefore also require you to upgrade the visual back and diagonal to a 2" fitting.

Personally, I always consider my eyepiece choices in two ways. The first is to step up and down in focal length in steps of approximately 1.41X (root 2), which for human vision equates to one noticeable step in image brightness. At high magnifications where the atmosphere is the limiting factor you may want closer steps or a zoom eyepiece to adjust for the conditions at the time. In the UK this will start to come into play int he 150X-200X magnification range.  If you were to follow these steps using your 9mm as a base you would be looking for 9 - 12.7 - 18 - 25.4 - 35.8. Your existing 40mm replaces the 35.8 and then the X-cell LX range matches the other numbers quite nicely. That isn't a coincidence because the eyepiece designer used the same method when deciding which focal lengths to produce.

The second is to consider the exit pupil that an eyepiece will give with a certain telescope and compare that to the type of object you wish to observe. Exit pupil is given by eyepiece focal length / telescope focal ratio, so in your case this is easy as it is just eyepiece focal length / 10. Your 9mm gives an exit pupil of 0.9mm and your 40mm an exit pupil of 4mm. As a starting point consider the following exit pupil ranges:

• Splitting double stars: 0.5mm-max
• Lunar and Planetary: 0.85-1mm
• Star Clusters: 1mm-max
• Unfiltered extended objects (galaxies, nebulae): 2mm-max
• UHC Filtered nebulae: 2.5mm-max
• OIII filtered nebulae: 3mm-max

Under urban skies your maximum exit pupil is likely to be around 5mm before the sky background becomes too light. If you have an observing location with very dark skies and your eyes are young enough to still dilate far enough you may be able to go to 7mm.

2 hours ago, ScouseSpaceCadet said:

The 9kg rating with a steel tripod relates to the AZ5,

Thanks for the correction. 

I don't think you should put a heritage 150p on an eq5. Any Newtonian on an equatorial mount needs to have tube rings so that you can rotate it as required. With the heritage you haven't got half the tube to fit any rings to, and fitting them to the part that is there will prevent the trusses from being retracted. 

I believe the rating of the azgti with the heavy duty tripod is actually 9kg so may be a better option than initially thought. 

On 19/09/2021 at 14:34, Photonic Nights said:

I've been trying for quite a while now to purchase a second Explore Scientific 8.8mm 82 degree ep for my new APM binoscope (I already own an ES 8.8mm). Unhappily, whether it's due to Brexit or Covid - or an amalgam of these two "conditions" - it seems that ES wide-field eyepieces in particular are exceedingly hard to come by here in the UK at present. With Televue waaay beyond my reach for now and in the foreseeable, I've hit upon Skywatcher's eyepieces instead, which do seem available here in the UK. The trouble is that I'm really out of my depth with Skywatcher's eps. I'm looking for mid-power ones that'll give me approx 45x~50x mag, which I guess is getting towards the upper 'panning' limit for this 70mm SD binoscope (given the fitful viewing conditions here in the UK). Someone did recommend a pair of 8mm Sky-Watcher SWA 70s. Can anyone back up this claim? Otherwise do upper-end SW eps have a good reputation? 

Regards

 

Personally, I think that BST Starguiders are the most comfortable eyepieces to use for binoviewing if you don't need glasses to observe. Their coatings aren't as good as top end eps but if you're not using them for bright objects you might not notice. There are a couple of 8mm available in the classifieds at the moment so you could always try them and only risk losing the cost of postage if you don't like them. 

14 hours ago, Don Pensack said:

I would really hunt for one.  I think JOC might have discontinued the 8.8mm in favor of the 8.5mm, as they recently discontinued the 6.7mm in favor of the 6.5mm.

I would look before the market place is completely dry of them.  You might have to look for US as well as EU sources.

Do you know if the new eyepieces are redesigns or have they just changed the rounding for marketing purposes?