Skywatcher Skymax 102/1300 - any good for AP?

[Alveprinsen]

So, I've recently done some imaging of M42 with my Skywatcher Evostar 80ED Pro, but 600mm just doesnt cut it for me. I want to fill the whole chip. So, I've suggested putting in a 2x barlow, which people in the community tells me is a very bad idea...

I've suggested putting a reducer in my 2700mm Skywatcher Skymax 180/2700, but I am told that the reducers often if not mostly produce a poor image, unless its a really expensive high-end kick-ass reducer...

SO! ... How about this... I buy myself a Skywatcher Skymax 102/1300... for M42 and any other equally sized heavenly object... Is this scope any good for astro photography? Anyone have any experience with it?

Considering the price-tag: 206 Euros - it would be worth it to image M42 in all its splendor.

What do you guys think/know?

Sincerely, Alveprinsen.

[nmoushon]

This would not be a good scope to image any DSO. Maybe planetary  but I'm not expert in that area so I'll leave it alone. But for DSO imaging, like M42, this would be horrible. The reason being is it has a very very slow f/ratio at f/12.7. This would require extremely long images and lots of them. Another problem is the focal length. You will need a mount that is hooked up with guiding to be able to image at the long focal length other wise you would only be able to get an image of maybe one second before you start getting star trails. Long FL imaging tends to require higher end equipement and thus tends to be more expensive. Sorry to burst your bubble.

I know that you want to "fill up your chip" and I have the same desire. Depending on your camera but with my 450D and ED80 with reducer M42 and M31 fit very nicely in my FOV and fill up the frame almost all the way. Which for me is nice because it gives a bit of the space around the target to help give a bit of scale and more stars.  Here are my M42 and M31  and here is my M8 and M20 all shot with my Canon 450D and my ED80. M8 and M20 are a bit smaller  than the other two so doesn't fill up the chip as much as M31 and M42 but all were very slightly cropped just to get rid of the corners that didn't quite line up because I had different imaging session that were months apart.

If you are serious about getting as long a FL as possible the I would look into the fast imaging Newtonians. They can be between 600-1200mm in FL but are fast at a ratio of f/4. Depending on which one you get will dictate which mount is needed to be able to sope with the telescope. Obviously the shorter the FL the less expensive the mount you will need.

[Alveprinsen]

The reason being is it has a very very slow f/ratio at f/12.7. This would require extremely long images and lots of them. Another problem is the focal length. You will need a mount that is hooked up with guiding to be able to image at the long focal length other wise you would only be able to get an image of maybe one second before you start getting star trails. Long FL imaging tends to require higher end equipement and thus tends to be more expensive

Thank you for the input.

If I invest in this 102/1300 maksutov, I would be running it side-by-side with my Orion Starshoot Autoguider hooked up to my Evostar 80 ED with 2x barlow. The autoguider exposure time when running at 600mm with no barlows is like 0,5 sec. Even with a 2x barlow boosting the scope to 1200mm I should be good with a 2 - 4 sec exposure time for the guiding scope.

My NEQ6 Pro mount with guider runs pretty smooth, and 10 minute subs should be no problem. Considering the high F-ratio, I might need to go a bit higher than that too. Perhaps even 15 minutes.

But if an F ratio of 12 is an absolutely no-go for deep space astro photography, I guess I will have no choice but to look for other options.

I have to admit, I am no fan of those newtonians. They appear to me as big and clumsy things, with the the eye-piece in the wrong end of the tube.

Sincerely, Alveprinsen.

[nmoushon]

Thank you for the input.

If I invest in this 102/1300 maksutov, I would be running it side-by-side with my Orion Starshoot Autoguider hooked up to my Evostar 80 ED with 2x barlow. The autoguider exposure time when running at 600mm with no barlows is like 0,5 sec. Even with a 2x barlow boosting the scope to 1200mm I should be good with a 2 - 4 sec exposure time for the guiding scope.

My NEQ6 Pro mount with guider runs pretty smooth, and 10 minute subs should be no problem. Considering the high F-ratio, I might need to go a bit higher than that too. Perhaps even 15 minutes.

But if an F ratio of 12 is an absolutely no-go for deep space astro photography, I guess I will have no choice but to look for other options.

I have to admit, I am no fan of those newtonians. They appear to me as big and clumsy things, with the the eye-piece in the wrong end of the tube.

Sincerely, Alveprinsen.

Good to hear you already have a good mount a guiding setup. That really helps.

The f/ratio is a really big killer for AP. I don't know the exact math but a 15min exposure at f/12.7 would by like a 1 or 2min exposure at f/4. It is just straight up impractical and a waist of money and time. GREAT for planetary view but not AP.

If you aren't a fan of the Newts then how about looking at a 6" RC. Has long FL and with a reducer can be a very good imaging scope. I forget who has one here but they have post in the last week or two some great shots with it. I've heard it can have some collimation issues but once thats sorted out its a real treat. The 6" or 8" RC will be my next scope purchase when I can afford it. My ED80 is an amzaing wide field scope and will be keeping it forever. But like you I desire the long FL as I'm a big fan of galaxies and they tend to be very small. So I know where your coming from. Another added bonus is the EP at the right end

[Alveprinsen]

...how about looking at a 6" RC. Has long FL and with a reducer can be a very good imaging scope...

I must honestly say, I did not know what you ment by "RC". For me, RC is like Royal Coca Cola...

I assume you mean one of these: GSO Ritchey-Chretien RC 152/1370?

Its F ratio is 9 though... still twice whats recommended I guess?

And its about as expensive as a 250/1300'ish newtonian at F4,7

[nmoushon]

Thats what I'm talking about. Sorry about the confusion.

Yes they are a bit pricey for their size but the optics are very good. Yes the f/ratio is still high but with a recuder it can bring it down to around f/6 or so. Which is about a normal f/ratio. F/4 is considered fast so f/6ish is normal and f/9 is slow and f/12.7 is sluggeshly slow lol.

They are pricey and is why Newts are very popular because with a Newt you get a lot for your money.

Sorry but I just noticed where this is post is posted at. If you copied and pasted these posts in a new post under Equipment->Scopes/Whole Setup you'll get a lot more responses. If you pm a GM they could move this whole post over for you.

[Alveprinsen]

Thats what I'm talking about. Sorry about the confusion.

Yes they are a bit pricey for their size but the optics are very good. Yes the f/ratio is still high but with a recuder it can bring it down to around f/6 or so.

Sorry but I just noticed where this is post is posted at. If you copied and pasted these posts in a new post under Equipment->Scopes/Whole Setup you'll get a lot more responses. If you pm a GM they could move this whole post over for you.

I've been adviced not to use a reducer since rumors has it reducers generally give poor results.

Besides, if I use a reducer and cut the 1300 in half, I'm pretty much back to where my 600mm Evostar is at... Which is kind of the point.. I want to double my 600mm.. Cant use a barlow, because it will be too slow, and cant use my 2700mm with a reducer because image will be Rubbish.

I guess its either buy a 10k euro Cassegrain, OR, a 400 euro Newtonian...

[rowan46]

I don't know if they do this on your side of the pond its fairly new over here 

http://www.firstlightoptics.com/reflectors/skywatcher-explorer-130p-ds-ota.html

you will need the coma corrector too

http://www.firstlightoptics.com/coma-correctors/skywatcher-coma-corrector.html

[nmoushon]

I've been adviced not to use a reducer since rumors has it reducers generally give poor results.

Besides, if I use a reducer and cut the 1300 in half, I'm pretty much back to where my 600mm Evostar is at... Which is kind of the point.. I want to double my 600mm.. Cant use a barlow, because it will be too slow, and cant use my 2700mm with a reducer because image will be Rubbish.

I guess its either buy a 10k euro Cassegrain, OR, a 400 euro Newtonian...

I think you got this reducer thing fixed up. They were saying a reducer with you current scope would be rubbish because of the current f/ratio that its at and thus would need an expensive one.

Reducers are used all the time with great results. I use a reducer with my images. A reducer is a great piece of hardware that can really improve your imaging. And your correct that the reducer will reduce you focal length but not by half. The typcal reducers are between .65 and .85. They do have .5 but they aren't typical. The reducer you would get with the RC would bring it between f/5.85 and f/7.65 and bring the FL to 890mm-1164mm. The only other way you are going to get the long FL without reducers is going with a Newt. or increase your budget and look at different scopes. But reducers are not a bad thing at all. Don't be afreaid to use them as long as you get the approriate one that suits your scope.  They have a range were the work well in but are not universal.

Even the 10k Cass uses a reduser if they want to image with it. Even the large semi-proffessional telescopes use reducers. Like a 1m RC will use a reducer...though that reducer tends to be more expensive then most of our entire budgets but thats not the point lol.

[johnrt]

DSO imaging is mainly about 2 things. Firstly a sturdy and secure imaging platform - you have this covered with the NEQ6 which will allow you to take long guided exposures of 10/20 minutes without issue.

Secondly f/ratio. The scope you propose running at f/12 is woefully slow for DSO work, I assume judging by the fact you will be able to still fit in M42 at 1200mm focal length you are using a DSLR. This is never going to work.

I have the 6"RC mentioned above and use a x0.67 reducer to bring it down to a f/6. This is the slowest I would consider for DSO work. For example, a 10 minute exposure at f/6 on my scope would need a 40 minute exposure on your f/12 scope to match it.

Whoever told you reducers are rubbish and don't make good images is frankly wrong. They are in virtually EVERY imaging rig of any quality I have ever seen. I can't believe that without a reducer/flattener using a DSLR and the Skywatcher ED80 you get a useable field of view to the edge, the scope with display elongated stars caused by the curves in the optics.

Why do you wish to fill the whole chip of your camera? If you are printing up an A0 poster of your images then fair enough, but for display on the internet or just on a PC screen there is simply no need for all those pixels - simply crop out the edges of the picture and your nebula will fill the field of view.

[Alveprinsen]

I don't know if they do this on your side of the pond its fairly new over here 

http://www.firstlightoptics.com/reflectors/skywatcher-explorer-130p-ds-ota.html

you will need the coma corrector too

http://www.firstlightoptics.com/coma-correctors/skywatcher-coma-corrector.html

I dont see this giving me a focal length of 1200mm though. Unless I stick a 2x barlow in that thing, which would bring it up to like F10 - rendering it useless.

[rowan46]

I dont see this giving me a focal length of 1200mm though. Unless I stick a 2x barlow in that thing, which would bring it up to like F10 - rendering it useless.

Sorry I misread the post for some reason the thread started  started halfway through your post  apologies for the non sequiter

[Alveprinsen]

Whoever told you reducers are rubbish and don't make good images is frankly wrong. They are in virtually EVERY imaging rig of any quality I have ever seen. I can't believe that without a reducer/flattener using a DSLR and the Skywatcher ED80 you get a useable field of view to the edge, the scope with display elongated stars caused by the curves in the optics.

Why do you wish to fill the whole chip of your camera? If you are printing up an A0 poster of your images then fair enough, but for display on the internet or just on a PC screen there is simply no need for all those pixels - simply crop out the edges of the picture and your nebula will fill the field of view.

Hello.

I do have a 0,5 reducer, but I believe its a cheap one, and not matched specifically to my 180/2700 Mak. Its a 2" though, and fits.. just havent had the chance to try it out.

I've posted an image of M42 in this thread. The first picture is an un cropped pic taken with no flattener or anything, camera is a Nikon D3100 DSLR unmodded. If you look real close towards the edges, the stars are ever so slightly elongated. Elongation like this does not bother me though, since its not really that bad.

I wish to fill the entire chip because when I first invest time and effort into taking pics, I wish to avoid wasting space on the chip, thus making me have to take brand new ones with brand new equipment later. I'd rather fill it out with the object in order to get a closer look at finer details. And yes, I plan on having enlarged pictures of my future more successful images on my livingroom walls. I'm one of those guys who thinks size matters when it comes to photographs on the walls. My largest picture is a 160cm by 100cm full-frame super high-rez photo taken by a friend of mine. I want to be able to see details in the picture on the wall, without having to use a magnifying glass. Hence, I want to make full use of the chip.

[johnrt]

Your M42 image displays star elongation from the curved optics across 50 % of the field, about half way to the edge in each direction. You could add a flattener that does not reduce to sort this out. Skywatcher make a reasonably priced good one I believe.

If you do wish to have large prints then the only way to increase the focal length and maintain a useable f/ratio is to increase the aperture. To image at 1200mm focal length you will need about 250mm of aperture, in fact one of these.

http://www.firstlightoptics.com/reflectors/skywatcher-explorer-250p-ds-ota.html

Good luck!

[nmoushon]

There are very few objects as large as M42 and M31. So most of the time you won't be filling out your chip anyways. There are a decent about of nebula that you might have to even do a mosic with but that is usually a couple different objects close together making up one larger object. Which is fine just more of an FYI. Though if you ever get into galaxies then you can probably count the number on your hands that would even come close to filling out your chip even at 1000-1200mm FL. They are just so small that unless you have access to several meters of FL galaxies wont be filling out your ship.

But it really comes down to - if your set on aiming for around 1200mm FL at a decent f/ratio than the best bang for your buck is a Newt. Hands down. Especially with your budget. If you can wait a save to increase your budget then there are more options available to you. i.e. Mak-Newts, large SCT w/ reducer, large RC w/ reducer, large fracs. But those all can get very expensive. But seriously don't be afraid of a reducer. They are your friend

[JamesF]

Hmmm.  These were all taken with an f/11.8 127 Mak (I've not been at this very long, so I accept that none of them are stunning):

So I'd dispute that DSO imaging isn't possible with such a scope  However, look at this:

Not really comparable, is it?

The bottom line is that you really need to match your camera to your telescope to your target.  On a well-aligned mount that guides well it's perfectly possible to image some DSOs with a long focal length and get reasonable results.  Others, particularly the fainter or more extended targets just aren't really viable.

A fast imaging newt may collect a lot of light, but if it doesn't have the focal length you still won't get the image scale you're after.  On the other hand, whilst a metre and a half of focal length gets you the image size it collects light very slowly and if your target is too faint it may well be asking too much of your guiding.  At some point you have to start making compromises and those must be driven by the types of target you're interested in imaging.

The 102 Mak may work ok if you want to image globs and some of the brighter planetary nebulae, but for faint targets it will struggle.  For small, faint targets you probably need to accept that you're not going to get large scale images or go looking for a monster focal length scope on a mount that makes the NEQ6 look like it's made of rubber.

James

[Alveprinsen]

Your M42 image displays star elongation from the curved optics across 50 % of the field, about half way to the edge in each direction. You could add a flattener that does not reduce to sort this out. Skywatcher make a reasonably priced good one I believe.

If you do wish to have large prints then the only way to increase the focal length and maintain a useable f/ratio is to increase the aperture. To image at 1200mm focal length you will need about 250mm of aperture, in fact one of these.

http://www.firstlightoptics.com/reflectors/skywatcher-explorer-250p-ds-ota.html

Good luck!

You Sir, have the eyes of a hawk!

So I guess I need to get one of these flatteners then... Hmm, my equipment-list seem to be piling up!

Thank you very much for sharing your insight. I guess I will have no choice but to get myself one of those newtonians afterall... Oh well.

[Alveprinsen]

There are very few objects as large as M42 and M31. So most of the time you won't be filling out your chip anyways. There are a decent about of nebula that you might have to even do a mosic with but that is usually a couple different objects close together making up one larger object. Which is fine just more of an FYI. Though if you ever get into galaxies then you can probably count the number on your hands that would even come close to filling out your chip even at 1000-1200mm FL. They are just so small that unless you have access to several meters of FL galaxies wont be filling out your ship.

Hmm...

I've been wanting to attempt a full-chip sized M101. I can do it with my 180/2700... but.. at F15... hehe I'll give it a shot later this winter and see how it goes. My setup is pretty automated now, so if I set it to like.. 20 minute exposures, and just have it loop that for.. 9 hours or so... I think I should be able to start seeing something. I would use an off-axis guider as well for that. This is gonna be interesting.

Guess I'll have to get myself one of those big clumsy newtonians afterall then... hehe

[Alveprinsen]

Hmmm.  These were all taken with an f/11.8 127 Mak (I've not been at this very long, so I accept that none of them are stunning):

The bottom line is that you really need to match your camera to your telescope to your target.  On a well-aligned mount that guides well it's perfectly possible to image some DSOs with a long focal length and get reasonable results.  Others, particularly the fainter or more extended targets just aren't really viable.

For small, faint targets you probably need to accept that you're not going to get large scale images or go looking for a monster focal length scope on a mount that makes the NEQ6 look like it's made of rubber.

Actually, those pictures gave me a littlebit of hope... I will ditch my plans for this 102/1300 mak... and try out my 0.5 reducer on my 2700, see how that works out.

As for the small faint targets... and quote: "monster focal length scope on a mount that makes the NEQ6 look like it's made of rubber" .. I HAVE been considering the EQ8 Pro... But not until I get a more permanent setup on my own property. My rubbery EQ6 Pro and "short" focal length 2700mm mak will have to do for now..

but one day... EQ8 with one of those long focal length cassegrain kickass scopes...

Alveprinsen.

[Alveprinsen]

You could add a flattener that does not reduce to sort this out. Skywatcher make a reasonably priced good one I believe.

Are we talking one of these by any chance?

I am about to put in an order with FLO for some other stuff, I might just throw this one in the pile as well if its a good one.

[johnrt]

Are we talking one of these by any chance?

I am about to put in an order with FLO for some other stuff, I might just throw this one in the pile as well if its a good one.

Yes that's the one

[RikM]

The blurb says for f/5.5 - f/6. The ED80 is f/7.5, is it a close enough match?

[nmoushon]

The blurb says for f/5.5 - f/6. The ED80 is f/7.5, is it a close enough match?

1. I don't think the OP is looking to buy an ED80

2. On that note not sure if that is the right field flattener. It looks a lot like the one for the ED80 as Rik is suggesting.

[Alveprinsen]

The blurb says for f/5.5 - f/6. The ED80 is f/7.5, is it a close enough match?

Must be, cuz I'm using it...

[Alveprinsen]

Must be, cuz I'm using it...

Scratch that.. I misinterpeted the meaning..

So, is that flattener suitable for an 80ED or not? hehe, I'd hate to order it only to realize I've made a fool of myself...