Faster Scope for imaging

[DaveS]

Just so.

Which is why I advised Carole to beware of it, I'd torn enough of my hair out trying to get anything even superficially reasonable, as my image above shows.

Put an ASI 183 on the end and it frames Markarian's Chain quite nicely, but it's a bit expensive for a one-trick pony

[carastro]

Quote

Maybe a stupid idea, but why not use the Canon 400mm/5.6L lens instead?

I think that it should play excellently with your Canon body, and I suspect that'll be a more general purpose lens?

I use a mono CCD camera and am using the Samyang lens, but I also have scopes for less wide field imaging which are F7.5 and now having tested the speed of the Samyang lens I want to speed up my telescopes.

Carole 

[carastro]

@ollypenrice  Sorry Olly, that went a bit over my head, I think you are saying unless you pay a lot of money you can't get good fast optics and even Takahashi can't manage it. 

I am sure I can improve on what i currently have @ f7.5

Carole   

[Davey-T]

9 hours ago, vlaiv said:

Btw, if you want something really fast, close to Samyang and in focal length of above scope, maybe have a look at this:

Apologies for the mirth Vlaiv but have you read my thread on this scope and the CN thread ?

Dave

[RayD]

My one which Carole is going to try out is the f/6, same as Vlaiv's, and it is actually not bad at all.  However, I definitely tend to agree with @ollypenrice and think TS are pushing it to provide a quality and reliable instrument under this at this price range.  They work well at f/6 but I'm not sure I would want to try anything quicker from them.

[ollypenrice]

22 minutes ago, carastro said:

I use a mono CCD camera and am using the Samyang lens, but I also have scopes for less wide field imaging which are F7.5 and now having tested the speed of the Samyang lens I want to speed up my telescopes.

Carole 

Don't we all. Why is your Samyang fast? Because it is has a fast F ratio? No, that is the wrong way to look at it. It is fast because it works at low resolution. It puts the light from a lot of sky onto each pixel. That's great, but it means that you cannot capture small details. The way to speed up your present imaging systems is to bin 2x2 or 3x3 and, that way, you will put the light from more sky onto what are in effect fewer but bigger pixels. But you'll lose resolution, you say?  Yup, that's right. There is no alternative. That's what your Samyang is doing.

The bottom line is this: you have a certain camera with 'x' sized pixels. You want to image at a certain resolution so that means you need 'y' focal length. This focal length and pixel size will give you the image scale you want, making M33 a certain size on your chip. Fine. Now you want it faster. There are only two ways. You use a bigger objective lens of the same focal length or you use a dual/multiple rig. A focal reducer will simply have the same effect as binning. The same number of M33 photons landing on fewer pixels. Forget F ratio unless you are talking about a fixed focal length. Is a 1000mm FL scope of F5 four times faster than a 1000mm FL scope of F10? It certainly is. Is a 1000mm F10 scope reduced to F5 four times faster? Is an apple a banana? What does a 1000mm scope FL have to do with a 500mm FL scope? Nothing. Why compare them?

Olly

 

[Alien 13]

Has anyone mentioned a Tak Epsilon....

Alan

[newbie alert]

6 minutes ago, Alien 13 said:

Has anyone mentioned a Tak Epsilon....

Alan

Someone mentioned the epsilon

https://www.firstlightoptics.com/takahashi-epsilon-reflector-telescopes/takahashi-epsilon-180-ed-f28-newtonian-astrograph-reflector.html

[carastro]

Yeah right.  Lovely scope, too much for me to handle besides the price. 

Lol

Carole 

[newbie alert]

3 minutes ago, carastro said:

Yeah right.  Lovely scope, too much for me to handle besides the price. 

Lol

Carole 

I only mentioned it  as it will match the yellow ferrari 

[andrew s]

4 minutes ago, carastro said:

Yeah right.  Lovely scope, too much for me to handle besides the price. 

Lol

Carole 

How about the 130? Half the price! Half the weight! 😋

Regards Andrew 

Edited July 3, 2020 by andrew s

[carastro]

Thanks for trying guys, but I have had a reflector and sold it after a couple of years preferring to stick to refractors as they are less maintenance and I can use a dual rig on the refractors.

Carole 

[vlaiv]

4 hours ago, Davey-T said:

Apologies for the mirth Vlaiv but have you read my thread on this scope and the CN thread ?

Dave

I remember seeing a thread over here that discussed said scope but can't remember actual detail (good or bad).

[ultranova]

22 hours ago, DaveS said:

Beware of this 'scope. I have one and it is *very* sensitive to spacing and squaring on. It is *just about* usable with a not-too-big sensor, but I think anything above an ASI1600 size will be pushing the tolerances.

@ultranova had one, and we had a very long exchange of PMs trying to sort out the spacing before he got fed up and sent it back. I think he got his through a UK dealer which made it easy, but mine came direct from TS so I ended up hanging on to it.

It may well come with a TS camera rotator instead of the tilt adjuster, which can make working out the spacing from TS site data tricky to say the least.

Indeed we did have a good chat trying to resolve the spacing issues,, I wasted 2 clear nights trying to resolve the the warped stars at the corners , it wasn't  the fact the the camera needed tilting as the star distortion was very even in all four corners,

which for me , I could not live with, and I wasn't seeking perfection,, it was a real shame as it is a beautiful scope.

If I was you Carole I would really take your time on deciding and picking something, as Like Olly said, unfortunately, like most things you only get what what you pay for , there are exceptions I dare say but very rare. 

 

[Davey-T]

7 hours ago, vlaiv said:

I remember seeing a thread over here that discussed said scope but can't remember actual detail (good or bad).

Mostly extremely poor QC, however TS are supposedly checking all those they sell before despatch but whether this goes as far as completely disassembling them to find all the screws they haven't bothered to tighten I don't know.

Dave

These screws are not visible without removing all the adjusting screws and rear cover plate

 

[ultranova]

Wow, that's not good, glad you found the issue and sorted it.

Paul

[carastro]

OK, I am off to pick up the loan of Ray's TS80 Photoline this lunch time - socially distanced and masked etc of course.

So will be giving that a try out - thanks Ray.

Carole   

[gorann]

Why not go for the 80mm Esprit? About the same price as the TS, f/5 and proven high quality. You should of course get it with the dedicated Esprit 80 flattener.

https://www.firstlightoptics.com/esprit-professional-refractors/skywatcher-esprit-ed-80-pro-triplet.html

[carastro]

Quote

Why not go for the 80mm Esprit? About the same price as the TS, f/5 and proven high quality. You should of course get it with the dedicated Esprit 80 flattener.

https://www.firstlightoptics.com/esprit-professional-refractors/skywatcher-esprit-ed-80-pro-triplet.html

Esprit's are on my list too, but if I get one it will probably be the Esprit 100.  I have just come back from Ray's where I took a look at his Esprit 100 and after discussion with him I think that may well be the one I will end up with, but I am going to try out his loaned TS80 Photoline in the first instance and see how I get on with it.

Carole 

Edited July 4, 2020 by carastro

[gorann]

1 minute ago, carastro said:

Esprit's are on my list too, but if I get one it will probably be the Esprit 100, and after just coming back from Ray's I took a look at his Esprit 100 and after discussion with him I think that may well be the one I will end up with, but I am going to try out his loaned TS80 Photoline in the first instance and see how I get on with it.

Carole 

My first idea was actually to suggest an Esprit 100, since I have one and love it, but then I thought you were in the market for an 80mm refractor. You cannot go wrong with a FLO tested Esprit 100.

[carastro]

Quote

My first idea was actually to suggest an Esprit 100, since I have one and love it, but then I thought you were in the market for an 80mm refractor. You cannot go wrong with a FLO tested Esprit 100.

I was trying to get a similar FOV, but using Imaging toolbox today, the Esprit 100 interestingly gives a slightly widely FOV than my ED80, plus is has better design features than the Esprit 80 that suit my needs.  It's a fair bit more expensive, but I am sure will be worth it.  

Carole    

[RayD]

Good to see you, Carole.  Hopefully you'll enjoy having a play with the 80mm Photoline.

As I mentioned and, as noted by @gorann, you won't find much wrong with the Esprit 100 and it has the ring mounting rather than the foot mount which you want.

If you have any questions about the TS just shout.

[carastro]

Thanks Ray, was nice to see you and do something normal after all these months, albeit with masks and rubber gloves on.   Nice to see your mum and observatory too.

Have just shot off some questions to FLO. 

Carole 

 

Edited July 4, 2020 by carastro

[ollypenrice]

 

What an absolutely lovely and classic SGL thread this has turned out to be!

Olly

 

[gorann]

4 hours ago, carastro said:

I was trying to get a similar FOV, but using Imaging toolbox today, the Esprit 100 interestingly gives a slightly widely FOV than my ED80, plus is has better design features than the Esprit 80 that suit my needs.  It's a fair bit more expensive, but I am sure will be worth it.  

Carole    

Carole, you may not want to wait for too long to order your Esprit 100 - deliveries of refractors (and other astrostuff) are now drip feeding in from China and who knows what it will be like in the future - as noticed in this thread. I just got an ASI2600 camera that I ordered in February:

 

Edited July 4, 2020 by gorann