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lucid

Edge HD 8" or 9.25"

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So after a long while researching I feel the best place to spend my money is on the 8" Edge HD OTA... I think...

Why does the 9.25" cost two and a half times more?

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Are you doing deep sky photography? If not and you are visual only, then the standard C9.25 is only a few pounds more than the 8" Edge and is considerably better on planets.

The only reason to get an Edge is if you need coma free optics for AP.

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Are you doing deep sky photography? If not and you are visual only, then the standard C9.25 is only a few pounds more than the 8" Edge and is considerably better on planets.

The only reason to get an Edge is if you need coma free optics for AP.

True.

And if you want to do deep sky astrophotography are you sure you want to do it at this kind of focal length and focal ratio? Do you understand the issues? They are numerous, believe me.

Olly

http://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/22435624_WLMPTM#!i=2277139556&k=FGgG233

Edited by ollypenrice
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I have an Edge HD 8 and a C11 and had a C6. For visual use only, the Edge 8 to me has a refractor-like feel to it. The moon with Delos eyepieces has been stunning. I know a few other people who have said "what till you see the moon in an Edge!"

I loved my C6 and my C11, they are great scopes. But I have never had a feeling from them that they were refractor-like - they have other advantages and still give a great view. I'm not saying the Edge is the same as a frac, just that for me it is much closer to that feeling than my regular SCTs.

I have a lot more observing to do with my Edge, but I can definitely say the advantages are not just for imaging if you will do general observing with them, especially with wide eyepieces. Mine will also be ideal used on my giro mount, as targets drift away from the centre and the sharper edge will pay off.

I did intend to dabble with DSO imaging with my Edge, but I would consider one for visual use only if that type of scope fits your needs. The big issue though is the price. Is it worth the extra over the regular SCTs? This I think is a personal choice. The Edge 8 seems fine price-wise to me, but I don't think I would go for the 9.25 or 11 Edge on current prices based on my needs and budget. For the price of an Edge 9.25, I got my 16 inch goto dob and one or two quality eyepieces. For my needs, the latter is the better value.

I'm not saying I don't think they are worth it, quality costs, just that for me a dob would represent better value. For imaging planets (I have only had a few dabbles) I think I would be drawn to the C9.25 having seen Damien Peach's amazing images and incredible talent. If it was good enough for him to use...

Can't lose either way. A well-priced regular SCT, or the excellent edge performance.

As said, I have not used the Edge exhaustively, so I hope others will chip in who have and definitely best to check out reviews from people who can tell you far more about it than I can.

PS I would agree that SCT's are not the easiest scopes to image DSO's with. The Edge 8 should be a bit easier for me than the C11, with its mirror lock and air vents, shorter focal length, light weight, etc. I am however probably going to enjoy imaging the moon with it more, as I like pottering around with my webcam.

Edited by Luke

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Because it's almost 2.5 inches more :eek:

It seems a big price gap for 1.25" more... but Im a newb, I don't know, that's why I'am asking.

Also, my plan is to keep the scope with me in the boot of my car, as I travel around a lot, so perhaps the smaller scope if a better fit for my circumstances?

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True.

And if you want to do deep sky astrophotography are you sure you want to do it at this kind of focal length and focal ratio? Do you understand the issues? They are numerous, believe me.

Olly

http://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/22435624_WLMPTM#!i=2277139556&k=FGgG233

Well I've had a long interest in "traditional" photography and I can see myself sooner or later extending this into AP (and Im particularly thinking DSO), so that's why I thought it wise to invest in a scope that might be suited to that ambition (without breaking that bank too badly).

Is the Edge HD 8" on an EQ mount not a good option for AP? Is there a different set-up I should be considering.

I realise AP is going to be a challenge... but that's what I'm after! I just don't want to waste good money on a scope that might not be fit for purpose.

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Olly is eluding to the criteria for picking a scope and mount to satisfy the purpose you have planned for it. As has been mentioned the Edge series are particularly desireable for the flat fields they produce. But they do have long focal lengths giving sharp contrasty views making them very nice for  imaging planets where you have a lot of light - but with a narrower fov than you'd have in a dso imaging scope.

Dso's tend to be a lot fainter than planets and the equipment you choose will have different properties to the Edge. Apertures tend to be larger for their extra light gathering ability. And wider fov's because you'd be imaging much larger objects like nebulae and galaxies.You would also be peering deeper into space and want to gather photons quicker so you'd be looking for a lower focal ratio instrument.

The Edge will have a focal ratio of f-10 or above whilst a wide field imaging refractor would want to be f-5 or less. Also whilst imaging planets can be very successful on an alt/az mount, but for dso's an equatorial mount is pretty much mandatory. In either case it has to be accurate and large enough to support and move not only the ota with ease, but also a second "guide" scope and camera. Plus all the ancilliary equipment that will be installed on both (filter wheels, motor focuser, dew controler, etc).

My advice would be to get a copy of "Making Every Photon Count" by Steve Richards and give it a good read before choosing an imaging rig: http://www.firstlightoptics.com/books/making-every-photon-count-steve-richards.html

Hope that helps and gives you a few points to ponder :)

Edited by brantuk
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As Kim and Olly have said, if you want to get into DSO AP you should start with something more modest.  An ED80 on a HEQ5 or NEQ6 is the daddy and is almost the de facto standard for newcomers.  The NEQ6 mount will future proof you more.  ED80 = inexpensive, easy to use and well corrected to create some fabulous results.  Now that I have my FSQ-85 I still marvel at how good the ED80 truly is.  it is 10% of the cost and delivers 85% of the performance.  You pay a LOT for that extra 15%.

Guiding 2.5m of FL is going to be tricky and you coudl get discouraged even as a very competent terrestrial photographer.   I urge you to reconsider your plans.  I'd suggest a regular C9.25 SCT - a superb instrument (see what Damian Peech has to say) for your visual uses and for planetary photography if thats what you want to do and the aforementioned ED80 or a Altair Astro Wave 80.  Search for Badger's review of this instrument.

Good luck with your choice.

Steve

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Yes, I wouldn't go for a long focal length instrument of any kind when starting in DS imaging. I'd always start at a focal length of around 500mm. That actually remains my favourite FL but I'm passionate about widefield imaging going deep. It's great to have a long FL for galaxies but I'd get the hang of it first.

A Tak FSQ85 with a good small pixel CCD camera and a relatively modest mount will produce truly stunning images very consistently. A cheaper small semi apo will get close, especially on the smaller chips. Much of the cost of the premium scopes goes into increasing the corrected field.

Olly

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Yes, "Making Every Photon Count" is already in the basket, along with whichever telescope I settle on.

I think the reason the SCT attracted me was the apparent versatility with imaging, being able to mount the camera to the back or front (for shorter FL/ wider Ap, giving a flexible range of options?), in a system that seems very portable and storable. I live in a flat at the moment and envisage taking my scope with me wherever I'm working that week, or to the New Forest on weekends etc. To begin with (and I might be looking for the holy grail here), I'm looking for a good all-round telescope to learn about all kinds of visual astronomy, viewing the moon, planets and hunting for DSOs, knowing full well I will photograph everything I find. Perhaps I'm being naive... perhaps I've swallowed too much marketing from Celestron re the capabilities of their scopes?

And speaking of good all round equipment, what is the view on the Advanced VX that the Edge 8 comes with? Or is the opinion that generally the Skywatcher mounts are better?

I think I'm pushing my budget as far as I can justify with approx £1500. If you had that budget and were in my situation, but with the benefit of hindsight, what would you choose?

Thanks for taking the time to share your experience. Hopefully, I can avoid a costly mistake, with your input.

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Unfortunately there really isn't an "all around scope". Every scope will be better at one thing and not as good (or down right not good) at another thing.

For your intentions I think first you need to decide if you would be willing to lug around the extra size and weight of the C9.25 vs the 8. If you are then go with that. If not go with the C8. For imaging DSOs they will be pretty similar apart from the bit of extra focal length on the 9.25. If you get the dedicated reducer for the Edge series and not the standard .63 reducer the price is cheaper for the 8 than the 9.25. Just to keep in mind. For planetary imaging and viewing the 9.25 will have the edge over the 8. I believe because of the added contrast it brings...if I'm rembering this right. Viewing DSOs again the 9.25 will win but not by much. You might get a small but noticable difference at dark sites but LP skies I don't think the add 1.25" will provide that noticable of an improvement.

Since you are planning on imaging I would first spend the most money (with in reason of course) on the mount. It will make long exposure imaging that much easier. Though don't get me wrong, at both those FL guiding isn't the easiest. Then with what money you have left determine what scope to buy. Don't forget to include all the extras you're going to need in that too.

Thats what I would do anyways. Even with imaging with an ED80 I'm super super super glad that I did not stick with the CG-5 for a mount and jumped to the HEQ5. That was the single best desicion I've made in purchasing my equipement so far. Never try to go short with the mount. Especially when it comes to long FL. Yes, you can push a smaller mount to do what you want but it takes more work and will cause more problems. It might be just me but I prefer as little problems as possible.

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I guess you're talking about the Hyperstar. This has things going for it but be aware that it is a tricky animal because of its phenomenal speed. The light cone at around F2 is incredibly steep and so the focal plane is vanishingly shallow, meaning focus is critical. The SCTs focus using a simple moving mirror system and the standard system is not really up to the Hyperstar F ratio. Very fast systems are, in a nutshell, a can of worms and in reality can be devils to tune into good behaviour. Just be aware of what you're getting into. The biggest danger in AP is reading a product description and assuming it will actually work out of the box. It ain't necessarily so!

Olly

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and taking a largish scope, very large mount, guiding rig, camera, power pack, laptop, spiders web of cables etc etc etc with you everywhere in your car would be a nightmare! I cannot imagine it would be easy to pack away tidily and then set up every time you fancied a quick bit of imaging! Plus would your car insurance cover for the contents?

Alternatively, and i will probably get shot down in flames - as you say you are already into traditional photography, hows about you buy a smaller/cheaper mount and just image using your DSLR mounted directly on to it with a half decent lens? You may already have an appropriate lense and not realise it. If you have a search on here there are a few chaps making lovely images with just a dslr. Then whilst thats doing its' thing', look at the skies with something like an 8" truss tube dob. Whole lot will probably cost less, be much simpler to set up and take up a significantly smaller amount of space and give you what you want.

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I think an 8 inch scope is probably a good fit for me, in terms of portability for now. So then the next question becomes whether to get the standard or Edge HD. With only a £200ish price difference I'm leaning toward the Edge. I had initially looked at the Nexstar series, but discounted that as it seems an EQ mount might be more useful in the long run, albeit with a bit more to learn to begin with. I'm hoping the Advanced VX is going to be a reasonable mount, for a reasonable price.

Yes, I had thought that a few of my existing camera lenses would be useful. In particular I'm hoping to mount my Canon 28-300 L. Its a fairly big heavy lens tho, do you think it can be mounted on top of the OTA, with the Advanced VX mount?

I don't plan to live in my current flat forever. The plan is to look for a house in the next couple of years when my girlfriend has finished all her training. So then a bit more of a static backyard setup will be an option. I want whatever I plump for finally to grow with me, if possible.

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Before you spend a penny, then please research. Imaging DSOs at f10 on a mount like the Advanced VX is going to be very, very tricky (are you prepared to chuck subs in the bin?). Have you budgeted an extra £279 for the Edge focal reducer if you opt for the Edge?  How are you going to guide? Guidescope or OAG? What guide camera are you using?

If you want to image DSOs then an 80mm 'frac might be a better option. Much lighter, far easier to use (with good results) on a mount like the VX, a LOT faster than f10.

I fear that you will end up blowing your budget on kit that you will later find to be unsuitable for your purposes.

Yes, "Making Every Photon Count" is already in the basket, along with whichever telescope I settle on.

I think the reason the SCT attracted me was the apparent versatility with imaging, being able to mount the camera to the back or front (for shorter FL/ wider Ap, giving a flexible range of options?), in a system that seems very portable and storable. I live in a flat at the moment and envisage taking my scope with me wherever I'm working that week, or to the New Forest on weekends etc. To begin with (and I might be looking for the holy grail here), I'm looking for a good all-round telescope to learn about all kinds of visual astronomy, viewing the moon, planets and hunting for DSOs,

There's no such a thing. Planetary imaging needs a long focal length, big apertures and cameras that record movies at fast frame rates (the SCT is perfect for this.)

DSO imaging needs a fast focal ratio (the SCT is f10), probably guiding (very tricky at 2 metres focal length), and a camera that can expose for long periods.

knowing full well I will photograph everything I find. Perhaps I'm being naive...

DSO imaging is totally counter intuitive to normal daytime photography. Read the book before spending a penny.

. perhaps I've swallowed too much marketing from Celestron re the capabilities of their scopes?

LOL...I'll wait for Olly to comment on SCT telescope manufacturers marketing departments....

Yes,

And speaking of good all round equipment, what is the view on the Advanced VX that the Edge 8 comes with?

it looks undermounted to me. Especially if trying to do DSOs at 2 metres focal length.


I think I'm pushing my budget as far as I can justify with approx £1500. If you had that budget and were in my situation, but with the benefit of hindsight, what would you choose?

HEQ5, ED80 scope, finderguider and QHY5 guide camera.  Then a normal SCT (8" or 6") and a modified webcam for planetary.

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HEQ5, ED80 scope, finderguider and QHY5 guide camera.  Then a normal SCT (8" or 6") and a modified webcam for planetary.

I could not have put it better myself.  That would be a fantastic setup. I would push the boat out slightly more though and go for the C9.25 and the NEQ6.

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There can be a temptation to think "big is better and more 'powerful' ". Not always true in astro photography. Many popular dSOs are quite large and the scope needs to focus the light on the sensor,not necessarily magnify the object massively.

Sent from my iPhone using Tapatalk

Edited by kirkster501
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I could not have put it better myself.  That would be a fantastic setup. I would push the boat out slightly more though and go for the C9.25 and the NEQ6.

It'd blow the budget though, and mean a much heavier mount to setup. The HEQ5 would be perfect for a 80mm frac and will easily carry a SCT for planetary or Lunar imaging/observing. A Mak would be good for planetary, but the cooldown times might be a bit much for a portable setup.

Edited by Zakalwe

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Different scopes for different strokes... that's the message coming across! :)

With my budget I'll start somewhere and inevitably add to it over time, but thanks for the varied advice.

Book is on order!

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One option I don't see mentioned... using two scopes with the one mount :D the Edge 8 + AVX is a great combo for visual and will give you the long focal length for planetary imaging. When you feel you want to move on to DSO imaging, keep an eye out in the classifieds or Astro buy and sell for a used ED80. Problem solved ;)

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Thanks. Would the AVX be robust enough to hold an edge 8 and an ED80?

It'd be perfect for visual with both and for planetary/Lunar with the Edge*. No need to mount both together and you'd use the 80mm or DSO imaging (perhaps with a small guidescope).

*Unless you intend to do DSO imaging, then there'd be little advantage of going for the Edge. Get a standard SCT and save some of your budget.

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One option I don't see mentioned... using two scopes with the one mount :D the Edge 8 + AVX is a great combo for visual and will give you the long focal length for planetary imaging. When you feel you want to move on to DSO imaging, keep an eye out in the classifieds or Astro buy and sell for a used ED80. Problem solved ;)

ahem :grin:

HEQ5, ED80 scope, finderguider and QHY5 guide camera.  Then a normal SCT (8" or 6") and a modified webcam for planetary.

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