Celestron edge hd scopes.

[vince 66]

Has any one on here owned a standard c8 and then moved on to a edge hd 8 inch scope. I am asking this because I have read a lot of rave reviews on the net about the edge hd scopes. Jaw dropping views sharper images etc. I have also read that there is no difference for visual use or very little. Can any one throw any light on this subject.

[Naemeth]

From what I've read, you won't notice much difference visually, and if you are only doing planetary imaging then there is no difference between the Edge and the Standard. However, if you are doing DS-imaging, the difference of Edge optics is noticeable.

HTH

[DrRobin]

Hi,

I bought a C11Edge, but didn't own a large SCT before. With a Canon 600D the stars are sharp right to the edge of the frame without the need for a flatener or corrector lens. I also notice very little difference in light across the full frame, although I still take 'flats' they probably aren't really needed.

I would say for visual, the planets and small chip cameras there is very little to justify the price. If however, you have a APS or large format camera then it really comes in to it's own. I bought mine as they were on special offer at the time and FLO had an ex demo that narrowed the gap a bit against a standard C11.

You also get a bigger rear cell, large diagonal and huge eyepiece (both unused by me), together with mirror locks and vents to improve cool down. I don't have any figures on the improved cool down time but I doubt the vents do very much, they are so small and with no fans the air flow through them will be very small. They do however, allow the scope to breathe which might be an advantage.

So overall, if you want to do large format DSO imaging, or you can get one at a good price, then go for it. If not I would seriously consider the standard C11, things like focal reducers are cheaper for the standard scope.

Robin

[vince 66]

At the moment I only do visual. So if I was to purchase a edge hd I would first and foremost be looking for a improvement in visual performance over a standard sct . Ap is something I am tempted to have a go at later on.

[Rickstar]

I have the Edge 9.25 and the Ethos 13mm EP gives 180x and a field filling image with no sign of curvature or other image degradation right to the edge. The Edge field flattening lens assemby clearly works.

[ollypenrice]

I never saw much difference in visual use with visiting Celestrons but I never had them back to back.

For DS imaging the Edge is better by miles but the F ratio is far too slow for me and the reducer is expensive. I would, personally, have no interest whatever in doing DS imaging at F10 even with a cooled CCD capable of half hour or even longer subs. My own bottom line is F7 and even that is pushing it. What I don't know is the size of the image circle with Celestron's reducer? They seem to be a bit quiet on this one.

Olly

[DrRobin]

You could buy the Optec Lepus 0.62 focal reducer for a C11Edge from below. Back focus has to be set to 100mm, requiring a custom spacer, but that brings the F ratio in to your limits Olly.

http://www.optcorp.com/op-19411-lepus-hd-telecompressor-c11-edgehd-edition.html

http://www.optecinc.com/astronomy/prices/astronomy_price_list.pdf

$275 for the FR, Around $60 for the camera mounting plate, + delivery, import duty and 20% VAT, will be around £330 in the UK.

I haven't gone for one yet as I haven't settled on a camera/wheel combination and I also use a Crayford on the back of mine so the length is wrong, but might try this in the future.

Robin

[Rickstar]

I have the Edge 9.25 and the Ethos 13mm EP gives 180x and a field filling image with no sign of curvature or other image degradation right to the edge. The Edge field flattening lens assemby clearly works.

I meant to say "a field filling image of the moon"

[ollypenrice]

You could buy the Optec Lepus 0.62 focal reducer for a C11Edge from below. Back focus has to be set to 100mm, requiring a custom spacer, but that brings the F ratio in to your limits Olly.

http://www.optcorp.c...hd-edition.html

http://www.optecinc...._price_list.pdf

$275 for the FR, Around $60 for the camera mounting plate, + delivery, import duty and 20% VAT, will be around £330 in the UK.

I haven't gone for one yet as I haven't settled on a camera/wheel combination and I also use a Crayford on the back of mine so the length is wrong, but might try this in the future.

Robin

The link doesn't work for me but how big is the image circle of the Lepus reducer? I've seen 22mm bandied about but that is absurdly small and I hope it's wrong. I think Celestron claim 42mm for theirs. That woudn't be enough for my cameras but it would cover DSLRs and 8300s OK.

Olly

Edit; Link now active but no specified image circle for the Lepus reducer. That's not a good sign...

[DrRobin]

Optec's website says the Lepus is capable of fully illuminating a 22mm diagonal chip, so probably won't fully illuminate you 11000 chips. If the Celestron one does, I guess this is why they are so expensive.

Mind you have a job finding a scope that will correctly illuminate a fully frame ccd.

Robin

[ollypenrice]

Optec's website says the Lepus is capable of fully illuminating a 22mm diagonal chip, so probably won't fully illuminate you 11000 chips. If the Celestron one does, I guess this is why they are so expensive.

Mind you have a job finding a scope that will correctly illuminate a fully frame ccd.

Robin

That's true! However, 22mm is very small, hence the low price. Ah me, no free lunches anywhere!

Olly

[Davey-T]

The link doesn't work for me but how big is the image circle of the Lepus reducer? I've seen 22mm bandied about but that is absurdly small and I hope it's wrong. I think Celestron claim 42mm for theirs. That woudn't be enough for my cameras but it would cover DSLRs and 8300s OK.

Olly

Edit; Link now active but no specified image circle for the Lepus reducer. That's not a good sign...

Didn't Per have an Edge hd and Optec reducer in his sig until recently ? don't know if he ever used it.

Dave

[DrRobin]

There is a Celestron C11Edge 0.7 focal reducer on ABS at the moment. I am tempted, but it is still more than the Optec 0.62 new and the Optec is a bigger reduction. Hmm, will have to have a think.

Robin

[ollypenrice]

There is a Celestron C11Edge 0.7 focal reducer on ABS at the moment. I am tempted, but it is still more than the Optec 0.62 new and the Optec is a bigger reduction. Hmm, will have to have a think.

Robin

Bigger reduction but what can you do with a 22mm image circle? From your sig the H16HRC would be OK. Not the Canon by a million miles.

Olly

[DrRobin]

I am toying with the idea of buying an Atik 4000 mono, which is within a 22mm circle. My Canon is 22x15mm approx. I guess the Lepus would correctly illuminate a square of 15x15mm in the middle of the sensor and just ignore the dark edges?

It would be interesting to see someone who has a C11Edge and Lepus to see what it looks like?

Robin

[Baffa]

How good are those new Meade ACF otas? Think they are f8 and with a reducer, if they exist, might bring em to a quite fast light bucket.

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[ollypenrice]

I am toying with the idea of buying an Atik 4000 mono, which is within a 22mm circle. My Canon is 22x15mm approx. I guess the Lepus would correctly illuminate a square of 15x15mm in the middle of the sensor and just ignore the dark edges?

It would be interesting to see someone who has a C11Edge and Lepus to see what it looks like?

Robin

I can't comment on the C11/Lepus but the Atik 4000 is a great camera, not much used, and the square chip makes the most of any light cone. You can get a larger but less responsive chip with the 383 but I liked the 4000 more than a lot.

Olly

[perfrej]

Yes I did. No more. It kind of didn't fit into my world of astro imaging, so I sold it. It did do OK with 8300 camera - just a very slight vignette, easily outflatted.

It is refractors for me (or an MN)

/per