Mr niall

What is it you are trying to achieve specifically pal? Is it moon and planets you are interested in or more deep sky stuff like nebula's?

There's quite a few different routes you can go down but if you are looking for advice it would be easier if you told us your intentions. And what sort of budget do you have available?

@paul2019 is sort of right in some respects but nonetheless you can still achieve pleasing results with whatever you happen to have available provided your expectations are realistic.

The purchase of a barlow is very much dependent on other factors - mainly what sort of scope you go for, however a 5x is very niche and possibly not something you would need to think about buying straight away.

On 26/03/2020 at 13:37, tjs247 said:

I'll try different eye pieces tonight. It's in the middle of the day so best I could do is a rough diagram. 

 

No I actually meant pics of your scope and mirror

Can u post any pics? Might help

It is really interesting to compare different scopes, but like others I'm not sure how much of a "one vs the other" type conclusion you would glean from something like this. The 150p should blow the 80mm out of the water in every single category (not withstanding the obvious things like star shapes). Its just sooo much bigger!

I did a similar thing with a 70/900 frac and a 130p flextube recently (not by design just had two people with me) and the 130 was considerably better in every single capacity that was measurable.

What I will say though is that it is super interesting to see how well a scope performs - and this is only the sort of thing you can do I think when you have another scope there to compare it to so from that perspective I bet it was a really interesting thing to do! Thanks for sharing; I'll bet this would also be of interest to those looking to buy a scope.

edit; sorry I just mean for visual of course. For photography it would be a very different sort of comparison!

Actually scrub that - just tried it on Venus that’s the worst CA I’ve ever seen on any telescope

1 hour ago, Stu said:

SA can definitely be an issue, killing the fine detail, but at f10 the risk of that is lower than a faster achro. Worth checking for I guess.

I had a couple of quick looks this afternoon and the seeing was better during one of them. Granulation showed a little better to the point of seeing some darker knots and swirls in it. A little but of interest anyway.

wowsers I've never seen anything like that. I need to up my game!

33 minutes ago, Stu said:

Did you try the two side by side yesterday or are you going on memory?

I ask because I’ve found the views the last couple of days to be quite poor despite the clear skies. Seeing has been poor with little granulation visible, certainly nothing like I normally see. So it may just be the conditions?

No reason why the new scope should be worse, it is still f10 so likely to be reasonable well corrected. Are you seeing a lot of CA?

Yeah it is sort of memory I guess - but objectively speaking I'd definitely never noticed a yellow background before.

Funnily enough no noticeable CA at all. But I have never seen granulation and today was no exception!

30 minutes ago, DanyalAG said:

There are a lot of factors that can contribute to image degradation:

1. The seeing ( the usual culprit. )

2. Extinction i.e. the fact that the object you were observing(in this case, the Sun)was very low in the sky and thus the atmosphere degraded the image.

3.Inferior Eyepieces... Mostly the Eyepieces that are provided with a telescope range from being poor(kellner, ramsden, achromat lens etc) to fair(ortho, plossl)...so if you're observing with one of the cheaper ones... they could be the cause of the degraded images.

4. Even though your scope is an achromat, it has a focal ratio of F/10; at this ratio it should be very well color-corrected... however the sun is a bright object... so 'some' color fringing will occur.

Most probably, the color-fringing and washed-out effect is due to poor eyepieces. If its in the scope, you can check it at night by focusing on a bright star(vega, deneb) at high magnification, if the image is a perfect (tiny) disk, then you have nothing to worry about. If it does not come to a sharp focus, then your scope has spherical aberration... which is a fancy way of saying that the scope doesn't focus all the light to a point.

To answer your question, no bigger scopes do not usually suffer from bad images- if they are treated properly. They will usually provide you with a better image.

However, I'd recommend you get yourself a Newtonian if you want to get a bigger telescope (no color-fringing). Also you can get a Apochromat, but they're usually really expensive.

No there is no colour fringing at all. 

Eyepieces are Vixen NPL Plossls so I know they are not the problem.

I was having trouble focussing last night but SA didn't occur to me, I will investigate further thanks!

I’ve been trying out my new Meade 90/900 refractor with my Explore scientific solar filter today.

compared to my older 70mm frac (And the same filter) I found the view a bit... meh. The edges were sharply defined but I noticed a lot of what looked like some kind of light bleed - the background looked much more of a vague mustard colour and the sun maybe seemed a bit more washed out. With my old 70/900 it was a sharp circle on a dark background.

is this symptomatic of larger apertures and faster scopes in general or is there possibly something else going on? Maybe reflections or a lens issue maybe?

many thanks

Alkor & Mizar in ursa major is fun.

Polaris too, and Rigel.

Obviously epsilon Lyrae (the double double) and Alberio but you’ll struggle with them at this time of year.

Gamma Delphini is my favourite but again position isn’t great.

i think they call them “showcase doubles” - sky and telescope have done a few good guides.

It’s arrived! I’ve been looking for this at a reasonable price for the last 4 years. Finally found a copy for a half reasonable not quite eye watering price (although still pretty expensive but totally worth it)

Have you considered exit pupil as well?

I would say no eyepiece collection is complete without at least something in the 5-6mm range. I use a 40mm Vixen NPL in my 90/900 - this gives 22.5x but importantly a nice 4mm exit pupil (which is about the most I can physically get). There is a whopping difference in contrast between that and my 25mm (36x but a 2.5mm exit pupil).

The 25mm gives much more contrast (which is good for helping cut through light polluted skies) but does dim the image a fair bit compared to the 40mm as a result. Sometimes really faint stuff is just undetectable for me at 36x unless I've already dialled it in at 22.5x and know what I'm looking at! 

When fuzzy hunting I normally start with the 40mm - then if I find what I am looking for, move to the 25mm - then if it improves try again with the 15mm. 

Both the 40 and the 25mm have a wider TFOV than my scope can support so I get vignetting with either - which is why I went all the way to 40 rather than 30 - because of the increased exit pupil.

But on a more subjective note - nice big exit pupils are a dream when it comes to eye positioning and flexibility at the eyepiece you just get so much more wiggle room.

Thanks both that’s really useful!

Eq5 isn’t an upgrade over an Exos 2 really. 
why don’t you share specifically what your issues are here in case somebody here can help.

you are either going wrong somewhere in your setup (easily done) or the mount is faulty and the retailer must replace. 
 

but don’t go throwing money at a new mount yet until you understand your issue.

29 minutes ago, danorman said:

The imaging side of things would be purely to get some nice pictures at the end of it all. If I'm out with a telescope or reading a book under the night sky then I may aswell take some pictures which I'm heavily interested in. I understand that these pictures are formed in editing but that's another thing which I enjoy doing.

Those sorts of tasks, which may would find a ball ache, are actually rather nice for me given my lifestyle!

Good stuff - in that case you are all set!

35 minutes ago, danorman said:

You're meant to be filling me with confidence 

Sorry perhaps a tad flippant but the point is that with visual there is “little to go wrong” but with imaging there are many many many things that can go wrong. And it’s segmented too - most of the work in imaging actually involves sitting at a laptop long after (days / weeks) you’ve packed up and gone home. The time you spend outside with imaging isn’t time spent enjoying the peaceful night sky unless a) you are happy just looking up (for which you don’t need a telescope anyway) or b) you also take some sort of visual apparatus as well.

So you see - imaging isn’t what I’d call peaceful per se. Doesn’t degrade the fun of it, it’s just one word I wouldn’t really use to describe it.

9 minutes ago, danorman said:

have an incredibly stressful job and I feel something like this could be very peaceful.

Visual astronomy is perfect. Imaging is just about the last thing I would ever ever recommend to someone looking for a peaceful hobby. Rewarding? Sometimes. When it goes perfectly correctly. But normally just about one of the most stressful hobbies you can imagine!

Here you go;

https://astromart.com/auctions/astromart-auctions/telescope-refractor/show/focal-tanzutsu-15-45-x-45-zooming-refractor-cool-12046
 

it’s the 40mm not the 50 but this is the one I think. Brand is Tanzutsu.

Still looks pretty great to me!

Thanks for the responses all it’s always great to have people to ask for advice it can be such a lonely hobby sometimes especially when you are confused!

I did indeed by it from FLO but bought it in mid November as a Christmas present (December pay was already accounted for as kids wanted expensive computers and playstations!). I’m kicking myself for not testing it while the returns window was open but that would have been cheating wouldn’t it😉.

But from what I’m reading above it sounds like I may have a warranty claim after all. I was sort of hoping it was one of those things that may be easily fixed but doesn’t sound like I can easily fix it my self. FLO suggested the thing with winding the focusser back and forth too but that didn’t work. I’ll see what they think.

Thanks for the advice.

Hello all

i received a skymax 102 for Christmas, I’m having trouble with focusser backlash and I was wondering how much is reasonable for a Mak?

Im getting a full turn and a quarter of the focusser knob before the mirror engages in either direction and I’ll be honest it’s really getting me down. It’s making fine focus almost impossible; if you have a fraction past focus you spend the next ten minutes spinning the knob in the other direction until it engages again - but as it engages without warning you likely as not zoom back past focus and out the other side and have to start again!

Ive had a C90 and a 127 in the past and they were perfect 

many thanks

Niall

I was reading the following article:

https://www.skyandtelescope.com/astronomy-news/possible-interstellar-comet-headed-our-way/

A man called Borisov discovered a comet. Lovely stuff! Borisov works at an observatory. Super.

But what has really foxed me is that it looks like he caught this comet using what appears to be a sort of richest field dob. At 650mm it looks like a fairly specialist instrument. But he made it himself which is pretty cool and from the photos of the scope - and the photo's of the comet itself - it looks a lot like it was captured using an untracked mount.

So essentially an observer, with an amateur scope, that they made themselves, without tracking, captured a comet. I'd guess he's probably still using a capture and plate solving software based solution rather than the ole "George Alcock" method - but still, in 2019 that's pretty amazing. I thought NASA had fleets of satellites up there doing the same thing and he's beaten them all to it.

Gives us all hope!

Just now, Gary Shaw said:

Hi Mr Niall - thank you for sharing your experience...sorry to hear of your problems. I’m struggling here in US to find a quality scope so, after discovering the OO scopes and finding they are made in the UK, I was encouraged. OO sales have responded nearly instantly to 2 emails already and we are about to schedule a call to address my questions. I’d say a far better response than I’ve had anywhere except at iOptron where their tech support is outstanding.

regards

Gary 

That's great news - maybe they've made some changes over the last couple of years. Would be great if they had cos the scopes are amazing. Best of luck.

Personal opinion:

Great scopes, amazing mirrors.

"Variable" customer service, rarely answer emails, almost never return phone calls.

Scope quality extremely variable; good one's are spectacular - the best there is. Many others have issues that take a while to rectify.

For some reason, nothing takes a hit in terms of value like the resale value of an OO scope. They seem to crash in value the moment they leave the factory.

I nearly bought an OMC 140 about 18 months ago but the focus knob stuck and made a grinding noise every revolution, felt like the mirror was going to fall out... Looked amazing in carbon though.

2 hours ago, AndreH12 said:

What f number would you use? And for how long to keep the shutter open? 

They're both discretionary. You want to keep the F number as low as possible taking into account that most lenses show some bloat the closer they get to being wide open. 

I don't know your lens but you could google it I imagine people out there will have an opinion. Obviously the wider aperture the more light comes in so the more information you get but sometimes at the expense of sharpness. If you're not sure I'd go one stop up from your smallest stop to be on the safe side.

If you're shooting from a fixed tripod then you follow the 500 rule - that is 500/focal length of lens = maximum exposure in seconds before star trails. It's useful as a rule but in reality you're talking about 20-25 secs.