Can anyone recommend an AZ Refractor?

[EnigmaXXIII]

Hi all,

I've posted a couple of times on this forum asking for help with an AltAzimuth Telescope system - I was originally looking at buying a Skywatcher 200p GoTo for not only visual observing, but some simple Astrophotography. I was comparing this scope with a Celestron 6SE, however, I have since found out that this might not be a good option for AP, not only because of the dew issues, but for other optical limitations too.

During my research I have found that Refractors might be best for some Astrophotography. I would like to get some views of the planets, Jupiter in particular, with both my camera and naked-eye, as well as get some views of M42. So, can anyone recommend a Refractor Telescope on an AltAzimuth mount with GoTo functionality? I am aware of the limitations of AZ AP and the strengths of an EQ mount, though for various reasons I cannot get an EQ mount at the current time.

The one thing I assume might be an issue is the fact that I cannot do long-exposures with an AZ mount, will this negate the benefits of a Refractor as it has less light gathering capabilities than say, a 200p Dob?

I'm asking quite a lot so I would be grateful for any advice you could give,

Thanks in advance,

All the best,

John.

[Capricorn]

Alt/Az will exclude long exposure imaging, that means no DSO imaging.

You need a driven equitorial mount as the least, even that when accurately polar aligned would only enable exposures of around 20-30 seconds without trailing. Longer exposures mean a guide scope and camera.

Astrophotography is not an inexpensive part of this hobby and there is no realistic way to avoid a significant outlay to get going. The HEQ5 mount is considered the minimal, then you will want to have it as a goto for future expansion into a guided system also you want to image the objects not spend imaging time locating them. The scope many use a relatively small refractor but normally apo so again expensive, even an ED scope will show a small degree of CA which is often unacceptable. Camera is DSLR or a dedicated ccd, dedicated ccd's are again costly. Add the potential cost of a guide scope and camera and you get some idea of it all.

[EnigmaXXIII]

Alt/Az will exclude long exposure imaging, that means no DSO imaging.

You need a driven equitorial mount as the least, even that when accurately polar aligned would only enable exposures of around 20-30 seconds without trailing. Longer exposures mean a guide scope and camera.

Astrophotography is not an inexpensive part of this hobby and there is no realistic way to avoid a significant outlay to get going. The HEQ5 mount is considered the minimal, then you will want to have it as a goto for future expansion into a guided system also you want to image the objects not spend imaging time locating them. The scope many use a relatively small refractor but normally apo so again expensive, even an ED scope will show a small degree of CA which is often unacceptable. Camera is DSLR or a dedicated ccd, dedicated ccd's are again costly. Add the potential cost of a guide scope and camera and you get some idea of it all.

I know most of this already. I also know it's possible with lots of short exposures to get some amazing images.

I'm simply asking whether a Refractor on an AZ mount will work for viewing and photography to a degree or whether the Celestron 6SE or the Skywatcher 200p would be better?

[jam1e1]

Hi strongly recommend invest circa 10£ on 'making every photon count' its sold by FLO it will help you understand fundamentals also pros and cons of options, there is no easy answer as always trade offs and understanding fundamentals are essential for AP

[Marki]

No idea what your budget is and I'm not an imager, but something like an iOptron Minitower II (or Pro) is an motorised alt-az and will carry a refractor (well, a shortish tube one, f7 ish) ok. Something like a starwave 102 or even a 115 (if you use the counter weights) - reckon it would struggle with longer tube refractors though (f10 or above), though not tried myself. The mount has gps and goto. I have a minitower II and it tracks really well (I use it with an 80mm apo for "grab and go"). I suppose you could use it for lunar or planetary or short exposure photography with a webcam type thing and maybe stack and derotate frames in some appropriate software? Not suitable for for long exposure stuff for widefield and DSOs I would think.

As the previous poster recommends, I'd definitely get "making every photon count" though, whatever your astrophotography ambitions. Good luck with your choice!

[EnigmaXXIII]

Jam1e1,

Thanks for this info. I'll definitely check it out.

----

Mark,

There are pros and cons for each of the three scopes I've been looking at, and I literally cannot decide what pros and what cons outweigh each other...

[rowan46]

This is a bit left field it's not a recommendation merely a suggestion what about a http://www.firstlightoptics.com/reflectors/skywatcher-explorer-130p-ds-eq3-pro-goto.html

[EnigmaXXIII]

This is a bit left field it's not a recommendation merely a suggestion what about a http://www.firstligh...3-pro-goto.html

Unfortunately I'm not able to an an EQ mount at the current time. I live on the third floor and getting the scope and mount down will be a pain each night, especially with a weighty EQ mount.

[rowan46]

eq3 weight 7.5 kg + 130 pds ota weight 3.66kg= 12kg aprox

nexstar 6= 13.5 kg aprox

[EnigmaXXIII]

eq3 weight 7.5 kg + 130 pds ota weight 3.66kg= 12kg aprox

nexstar 6= 13.5 kg aprox

Oh wow. Interesting. I've never actually looked at the weights, I've only gone by how it feels. To me the EQ mount alone felt heavier than the 6SE...

[rowan46]

http://www.amazon.co.uk/Powertec-1605-Tri-Truck-Multi-Functional/dp/B000JJRA8W/ref=sr_1_6?ie=UTF8&qid=1354410987&sr=8-6

[EnigmaXXIII]

http://www.amazon.co...54410987&sr=8-6

>.>

I don't quite see how that's going to help me get it down the stairs... I'll end up with a broken Telescope before I've even started...

[rowan46]

pack the mount in a case or two bungee it it the trolley and put the ota in a backpack

[EnigmaXXIII]

pack the mount in a case or two bungee it it the trolley and put the ota in a backpack

I'm not continuing with this farce conversation.

[rowan46]

I used to do it with my scope and used to walk a little under a mile to a site for observing admittedly not down 3 flights of stairs just a couple of steps and 1 flight of stairs to the canal. Just pointing out there are compromises you can make when you are desperate enough. I'm sorry you think my observing routine was a farce unfortunately I took it quite seriously as it really was the best I could do until I downsized

[jnc71106]

I'm not continuing with this farce conversation.

How to make friends and influence people. Well done

[rowan46]

the reason nobody is firing off suggestions for what to use on an alt az mount is essentially it can't be done you can do planets and a few of the m numbers mainly m42 and clusters with 20 sec exposures. for other nebulas you need longer than 20 sec exposures

[EnigmaXXIII]

I'm not having ago at your routine, in fact, if you had explained that to begin with instead of posting a link or two with a few words before it I might have understood. However, it still won't work as lugging all of that down three flights of stairs every night just isn't practical. That's why I was looking at a smaller more portable system.

I am to the firm belief that anything can be done with the correct knowledge and determination. I am simply trying to learn and gain such knowledge. There are many work arounds that can produce some fantastic results. I'm simply asking for a scope recommendation that is somewhere inline with the two previously mentioned scopes.

[nightfisher]

If this set up is with on your budget Celestron Nexstar 5SE would serve you well for viewing and imaging planets and lunar, also using the correct filter you could view and image the sun with it, BUT be aware of the safety precautions with solar!

You might be able to get some image`s of some of the brighter deep sky objects using plenty of short images stacked together, but it would be hard work

i posted a link but having a little trouble, but you can find the celestron on First Light optics website

[John]

the reason nobody is firing off suggestions for what to use on an alt az mount is essentially it can't be done you can do planets and a few of the m numbers mainly m42 and clusters with 20 sec exposures. for other nebulas you need longer than 20 sec exposures

I think this is correct.

There is a huge amount of practical experience on this forum and it's given freely to beginners and the more experienced alike in good faith and is, in my experience, well worth taking account of, even if it does not always tally with your own expectations.

Many folks come to the forum with certain expectations, myself included, and find they need to modify them in the light of the advice they get.

If you don't agree with the advice offered that's your perogative but please don't criticise those who are trying to share.

[J_M_Franklin]

Good Grief, people are trying to help and your putting up fences...13.5kg is around 30 pounds...that is NOTHING for a backpack. I used to run 20 miles in 3 hours with a 75 pound ( ~34kg) whilst carrying a personal weapon..Now I know your not in the Army and I know that you may be of slight frame and not physically strong...

But the solution to any problem is COMPROMISE. Instead of seeing barriers, see solutions and you will find this a whole lot easier.

First Light have This in their arsenal..well worth a look and would solve the problem if you can put both the OTA and this on your back...Where there is a will, there is ALWAYS a way..

[EnigmaXXIII]

I'm not trying to criticise or put up fences at all. I'm saying that for the moment I really don't want to get an EQ mount, no matter the weight or the gear used to transport it. I want to get an AZ system and am asking which is a good system to get in light of the limitations of AZ AP. I know that there are certain compromises, fair enough, and I know that I won't be able to take some 'professional' grade images, but I also know that imaging is perfectly possible with AZ systems... I used to do it with my manual 200p Dob and obtained some quite respectable results!

All I'm asking is which out of the three options is better suited to AZ AP in light of the obvious limitations:

- Skywatcher 200p GoTo Dob.

- Celestron 6SE / 8SE (if necessary)

- Some kind of Refractor.

I apologise if I've previously seen rude, but I have said before I am fully aware of the restrictions and am willing to put up with them!

[rowan46]

in light of the obvius limitatations . There is no point spending the money for an ap refractor if you are going to put it an an az mount. therefore you may as well use the 6se, It's not suitable for ds imaging but then you know that. however you will be able to get m42, the planets and a few of the brighter clusters will stack at 20 secs. I honestly couldn't say how good the dob would be but it would have the same problem of field rotation hence I am pretty sure that you will be limited to the same sort of targets. Also I wouldn't like to carry an "8 goto dob down 3-flights of stairs without help. A wedge on the se mount may get you 5- 10 secs on your exposures which may get you a few more targets but it's still not ideal and you will probably be better with an lx modded toucan or lx modded spc900 rather than a dslr as the reduced weight will help tracking accuracy

[ollypenrice]

I have some sympathy for the OP who asked a specific question after adding that he was aware of the limitations of the alt-az system for DS imaging. (I will just say that DS taken in alt az would never get within a million miles of anything I'd call 'amazing,' though. You can get a squeak of the brighter objects and the nearer the celestial pole the better. Amazing? No.) However, if Alt Az is the question then here's my answer and it mirrors an earlier one.

I'd go for one of the iOptron towers. The larger one was favourably reviewed in Astronomy Now by Ian Morrison, a man who might just be said to know his telescopes . You'd then need to check out the length of refractor that would swing past the tripod. I could certainly recommend a few but that would be via PM if you're interested. If planetary imaging is your goal then a 4 inch apo will get fairly close to anything that's possible for visual planetary observing. (I remember watching a shadow transit from beneath a sodium street light in the middle of Wirksworth, once, in a Genesis.) However, for planetary imaging it will lack focal length and a C6 might be better. Personally I'd greatly prefer a good 4 inch apo for all other purposes but that's an old minefield so I'll just state my strictly personal preference and leave it.

Olly

[dph1nm]

the reason nobody is firing off suggestions for what to use on an alt az mount is essentially it can't be done you can do planets and a few of the m numbers mainly m42 and clusters with 20 sec exposures. for other nebulas you need longer than 20 sec exposures

This is not really true - you can do virtually anything you can do with longer subs, you just just need to collect more total exposure time to overcome the read noise. Short exposures are less efficient, but it doesn't mean they don't work if you are willing to put up with the extra times needed. I happily use a 4 " refractor on an alt-az mount for imaging - I would not hesitate to try any Messier/Caldwell object.

NigelM