What makes the EdgeHD 1400 so good?

[Hypnotist]

Hi guys,
Since I've been thinking about buying a Celestron CGE 1400 Pro, I was wondering if I should upgrade to a Celestron CGE 1400 Pro EdgeHD. What makes the EdgeHD so good? Can it see so much more than a plain CGE 1400 pro? What do you think about it?

Thanks
Bart

[NorthernLight]

Hi Bart,

it has been advertised as a much better off-axis performer than the regular SCT´s hence the name edge-hd (high definition). So I would assume it has been developed to rival Meades ACF (advanced coma free) SCT´s. The edge-hd´s I think are fully compatible with faststar (shooting at f/2) and have carbon fibre tubes (that prevent focus shift under changing temperatures), so if you are serious about AP the edge-hd is the way to go.
I was considering the 10" version but since the new GSO Ritchey-Chretien scopes came out I changed my mind.
Hope that helps a bit.
Cheers

[renormalised]

I'd still get the Edge HD and ACF over the RC's. Simply because their fields are flatter. The RC probably has very slightly better off axis coma reduction, but it's not by much. They're all pretty much of a muchness. Just that the RC is cheaper than the Edge HD and the ACF.

They're all good scopes.

[marki]

There is a lot of talk about these scopes on CN. Basically it is a standard SCT design with a field flattener glued into the rear of the baffle tube to give a big well corrected field for AP. As this seals the tube they have had to add cooling fans to have any real chance of reaching thermal equalibrium. They have also added mirror locks aka Meade LX200's. The basic gist of the conversation is that off axis performance is very good although there seems to be some conjecture over on axis performance improvement with many owners saying this is unchanged and one owner stating that he has owned a standard SCT which did a better job. There is still reported shift when using the focuser(celestron say there shouldn't be) but mirror flop is said to have been eliminated by the mirror lock which appears to be a good design. As celestron did not change the mirror design they are faststar compatable but you will not benefit from the corrected optics as the light never reaches the FF when using this system. So the advantages over the standard celestron SCT are a flat field, cooling and mirror locks. Are they worth the extra money? At the prices lists on the OZ sites I doubt it.

Mark

[Hypnotist]

Thanks guys,
but do you think it's a good scope, even though it isn't quite as good as celestron says it is?
Does it also produce fairly good deep sky images?

Thanks
Bart

[mch62]

Bart , I have an 8" I take with me on my travels and at both Hyperstar focus and Cassegrain focus the stars are nice tight pin points from centre to edge on my QHY10 at least, visually as well with TV eyepieces. Mirror shift is not a problem in the 8". i have fitted a feathertouch micro focus for hyperstar imaging as getting focus at F2 is a challenge but quite doable now. cool down is not a concern as you simple remove the secondary and with the bottom vents allow the natural air flow. i would think some one will come out with fan forced aftermarket units soon.
The much and long awaited focal reducer has not turned up from Celestron yet I think, but optic has one they say works???
I have had SC from both companies in the past and this is by far the best Sc I have had to date.
I would love to post a sample but my brand new laptop has died 2 days after transferring all my data over and is in at the doctors getting repaired. I haven't lost the data just have not got access to it for about a week. Go to the Yahoo groups for pictures.
Would i get a 14" --you betcha if I was not building an 18" Newtonian for a lot less:P (in OZ that is--say no more on that one):screwy:
Mark

[marki]

Hi Bart

You are in the US so it would be worth the plunge as by all means some of the pics these scopes are producing are nice. Here we would be better off buying a CDK as the price is not that much different. In OZ a CDK 12.5" is advertised for 14K AU and a CDK 17" for about 29K AU. Some of the early ads I saw for the HD's were up to 34K AU. Funny how no one is advertising them here now :P.

Mark

[Sylvain]

Bart,

It would depend if you are planning to do some SERIOUS AP.
It means you'll have to have the mount & other equipment to handle to very long focal length.
If you plan to go the fastar way, then as Mark said, the HD won't be worth the updgrade.
I won't "see" anything more, it is only supposed to deliver a flatter field, useful mainly for AP.
If I were you, I wouldn't bother, and I'd spent the extra cash in getting a couple of very nice eyepieces.

Cheers

[Hypnotist]

Sylvain,
The only dslr camera I have is the Nikon D40x. It's a good camera and I'm very happy with it. Do you think I could also use it for AP with the EdgeHD 1400?
Bart

p.s. I'm getting the CGE Pro mount together with that telescope, I've heard it's an excellent mount!

[Sylvain]

Bart,

I do no know much about the performance of the D40 for AP. You will have to check in the options regarding the noise correction, and to which extend it can be disabled. Also, since it is a Nikon it - to my knowledge - cannot receive the baader modification. This is assuming you are talking about deep sky. For planetary, a dslr is not suited. If this is what you want to do, go the DMK or webcam way.

You have to think about what you want to do with this scope. Given that you only have a D40, I assume you are more leaning towards visual observation? If this is the case, you will benefit little from the features of the HD.

To be completely honest, I do not quite understand the motives behind a flat field modification for these SCT expect when used on very high ends mounts with top notch equipment and aimed at small and faint objects (some planetary nebulas). A 3500mm focal length instrument is just extremely difficult to use in Deep Sky AP. Planetary no problem, but deep sky? You'd need a C8 or more to do a decent autoguiding on this! Especially since there is no focal reducer at this stage!

So besides planetary, deep sky AP with this tube means super heavy duty mount, and super accurate autoguiding, and that usually comes together with a nice dedicated CCD to make the most out of your package.

Sorry Bart, I don't thinks this is helping much, maybe you should try to explain what your priorities are, under which sky you will be observing etc.

Sylvain

[Bassnut]

Well put. For planetary, go for it, but not with DSLR. The stock mount that comes with it for serious DS would render the flat HD aspect mute. 3500mm FL is a whole different ball park. If you really must go that FL , just go with the SCT, you have a lot more to deal with than just a flat field.

A 14" HD tube on a Losmandy Titan mount or better and a sensitive CCD though would be a very nice rig.

[Hypnotist]

Sylvain,
So you think the CGE 1400 EdgeHD isn't suited for deep sky viewing or deep sky AP? Or are you telling me the D40 is a bad camera for deep sky imaging?

Clear skies
Bart;)

[DavidTrap]

The 1400 is not a beginner's scope for AP - try starting with a focal length ~600mm. You need to learn to walk before you run!

The D40 is not an ideal camera for AP - it will get you started, but there are significant limitations using Nikon (less software, less experience with modification) - I tried with my own Nikon gear and then bought a second hand Canon.

Save yourself a lot of dollars - join a club and look at what people are using and what sort of images they are producing - I speak from experience here!

DT

[mch62]

I found 3 frames from when I first night i got the 8"EDGE these were taken at F10 with an unmoded Canon D7. They are single frames reduced and compressed only no cropping. I didn't have the hyperstar then or the QHY10 but at Hyperstar the images show nice round stars across the field.
These were taken on an EQ6 and i have forgotten how long but from memory about 4-5 mins each. Hyperstar your time per frame reduces down to 30 secs to a minute depending on subject and of coarse the focal length reduces.I was also trying my QHY5 guider through a modified 50x9 finder for guiding and wanted to see how it went at 2000mm focal length.
One thing to remember is the distance from the internal reducer lens and the image plane is critical. Not sure what it is in the C14 but go the Yahoo forums have the distance. If you get it wrong the images will show stars out of focus towards the edge of field.This is at Cassegrain F10.
As of yet i have not tried any planetary imaging as I was looking more for the short focal length wider field for DSO's.

Mark

[Sylvain]

Bart,

I think David said it all. It would be a very good idea for you to join a local club or go to a few star parties before pulling the trigger on this purchase. Nothing beats experiencing for yourself, seeing what imaging with this or that equipment involves, what results can be obtained etc.

All very much depends on what you want to do with your scope!
As David said, the 1400 is no beginner scope for AP! It really is a better idea to start with a ~600mmish focal length scope. You will see that it already is a MISSION. And just have a look at all the nice images produced by the small 80mm eds! In AP, small scopes can produce wonderful wonderful images not accessible to bigger scopes.

The risk if you just go with this scope thinking that you will do some AP, is that you might get frustrated and lose motivation pretty quickly. Again, mastering a 3500mm focal length requires LOTS of experience and an excellent mount and guiding equipment. This FL will also prevent you from imaging large DSO. In fact at this FL, you will be unable to image many DSO, unless you do some crazy compositions - a whole new level.

So it's not that the 1400 is not suited for deep sky viewing or imaging, it's that it is a very specialised scope. I have seen some wonderful deep sky images with C14s, but of very specific objects - typically small in apparent diameter and faint.

If you are interested in general AP, then I do not recommend getting this big of a scope. For AP, the mount is generally more important than the scope - as long as its a decent scope. And also you would need something better than your current dslr if your goal is to do some serious AP.

All this to say: the 1400 is good for certain very specific objects, and requires extensive experience and equipment to master. From our discussion here, it seems to me that your are a beginner in AP. If this is the case, I strongly suggest to join a club and rethink what equipment to buy.

I cannot stress David's recommendation enough: join a club, go to star parties, go see for yourself!!! Really, this might save you a lot of dollars, a lot of frustration, and might avoid you spending a lot of money on some equipment that will not be suited for your needs.

Best of luck!
Sylvain

[DavidTrap]

To put it another way,

"It's not the size of the wand, but the magic that you perform with it."

DT

[el_draco]

There are some universal truths huh.... :D

[Hypnotist]

Sylvain,

Thanks for your concern. However when I get this scope my priority will be just plain viewing through the eyepieces with friends and family. As soon as I'm familiar with this scope, I will start to use it for some AP. I basically just want the best scope to have and work with, since I've had a Meade ETX 70 (it's not very good) for eight or nine years now and I know a lot about how it functions. The C14 can't be too different:P!

Thanks again
Bart

[DavidTrap]

All the best to you Bart.

DT

[Hypnotist]

Thanks David.

Bart

[Sylvain]

Bart,

I am sure you will enjoy the views through the eyepiece with the C14!
Its light gathering ability is just phenomenal! :D
Something you could do is maybe get the regular C14 but buy yourself a long focal length very wide angle eyepiece! This will tremendously improve your enjoyment of Deep Sky Objects!

Of course, if you have the budget for it you can go the HD way and also get the eyepiece! Just be careful these get very pricey!

When you start to get into AP, look for focal reducers! Hopefully these will be released soon. It will bring the F/D of your C14 to 6.3 resulting in a 2200mm focal length. Still big, but easier to manage than a 3500mm and more objects will fit in!

I reckon that when you start AP, start with Planetary! The C14 is a killer on these targets!!! There is A LOT to do, and it is much easier to set up than a Deep Sky rig. You will learn the ropes of cooling, collimation, acquisition, focus, processing, use of softwares, and importantly: it will be very rewarding! You will be able to get good planetary images pretty quickly, which will keep your interest and motivation at its top!
A nice thing is that getting started in planetary is not very pricey! You can use a webcam (cheapest option - pretty good results!) or a dedicated camera such as the DMK21. A cam like the DMK will also be useful in the future as it is able to autoguide your mount for long exposure deep sky imaging.

The C14 is a challenging instrument to master. It however is very doable with time and patience :). The key is to not lose motivation in the beginning, as it can get pretty frustrating. This, in my opinion, is where many give up using such big setups. If you keep your spirit up, keep taking your scope out and using it, the C14 will provide you with a lifetime of possibilities!

I think you are going down the right path starting with visual. My suggestion is to start AP with planetary, and then move on to DSO when you know a bit more how this whole thing works.

Also, while you'll be in the visual stage, keep your eyes open for that focal reducer! It can also be used in visual! A C14 at F/6.3 will have a much wider field of view for you to enjoy with your long focal length, wide field eyepieces!

I wish you all the best Bart, and if you can, please keep us updated with your progress! Also post some pics of your scope when you get it! It's always cool!
Sylvain :)

[Hypnotist]

Thanks Sylvain,

I guess I'll do what you told me to. It sounds very right. The deal is, I won't be getting the 1400 HD until my b-day celebration on October 30., so you'll have to wait awhile with my pics. But when November comes along keep your eyes peeled!

Thanks again and clear skies
Bart:thumbsup: