EdgeHD 800, Reducer & KAF-8300 Chip

[PhotoGav]

This is sort of a WANTED ad really, but didn't know where best to put it...

Does anybody out there use a Celestron EdgeHD800, the 0.7x Reducer and a KAF-8300 chip. I am questioning the results from my edge with reducer and QSI 683 and would just like to see a single sub taken with that setup by somebody else. So, if you can help I would truly appreciate it.

Thank you!

[Barry-Wilson]

Hi Gav

Adam Jaffe is a great imager (also resident on The Astro Imaging Channel) and he uses an Edge 800 and 8300 ccd (though 0.8 reducer; also uses WO Star 71) - ABin gallery http://www.astrobin.com/users/Footbag/

HTH

Barry

[PhotoGav]

Thank you Barry, that's very helpful. Shame he's not on here. His images on astrobin look excellent. Do you know where he is located? Does he have particularly good skies?! Anyway, certainly makes me think that I should be getting better out of my scope.

[Barry-Wilson]

He posts on Cloudy Nights and is in the USA (north somewhere I think), http://www.cloudynights.com/topic/416471-loose-rooster-observatory/

Good luck with your quest, Barry

[PhotoGav]

2 minutes ago, Barry-Wilson said:

He posts on Cloudy Nights and is in the USA (north somewhere I think).

Thank you, I will see if I can find him. In the meantime hopefully somebody on here will stumble upon this thread and have something to share.

[ollypenrice]

If you're worried about your raw data you could post a sub on here, too...

Olly

[Chris]

Hi, would one of the very questionable images from when I had an C8 Edge help?

I used the .7 reducer and Canon 350D AP-C sized sensor.

I can try and dig out a snap if it helps compare

[PhotoGav]

37 minutes ago, ollypenrice said:

If you're worried about your raw data you could post a sub on here, too...

Olly

I know that there is an issue, I don't need to post a sub!! I could post one for interest's sake when i have a comparison sub.

[PhotoGav]

26 minutes ago, Chris Lock said:

Hi, would one of the very questionable images from when I had an C8 Edge help?

I used the .7 reducer and Canon 350D AP-C sized sensor.

I can try and dig out a snap if it helps compare

Chris, that would be really helpful, yes please. All I'm after is a single raw sub with stars across the whole field. Thank you.

[Chris]

No problem, here you go

Using a very poorly EQ6 unguided at the time, so a bit of trailing.

IMG_3118.CR2

Top left corner doesn't look great. I have another sub of NGC40 that looks a bit better thinking about it, but I've exceeded my 20meg limit on this thread so would need to email it to you

 

[PhotoGav]

Thank you Chris, that's very interesting. Here's your sub:

 

And mine:

 

 

The left side of mine has something dodgy going on. Your sub certainly confirms that it can be a great deal flatter... Thank you.

 

[Chris]

I see what your saying. Is your imaging train slightly out of orthogonal? My NGC40 sub looks even rounder in the corners, so maybe the reducer is sensitive to camera placement and can vary a bit each time it's attached? 

[PhotoGav]

That is possible, though I can't see how to change anything... The reduced is screwed onto the visual back, the T-adapter is screwed onto the reducer and the CCD is screwed on to the t-adapter. So everything should be fine and I can't adjust anything anyway. The strange thing is that without the reducer the stars are much rounder all over. I've tried a second reducer and results were identical. I conclude that there is a misalignment internally to the OTA that I can't do anything about that shows itself at the edge of the light cone that only the reducer brings on to the chip. I've spoken with David Hinds and they advise that shipping it back to Celestron USA, testing and subsequent replacement parts would probably clock up to more than several hundred pounds. I think that I will probably buy a new EdgeHD 800 as I do like the scope and can't find a suitable alternative with such a long focal length. Just beware of a cheap EdgeHD 800 appearing on astro buy & sell!

[Chris]

Oh mate that's not great news, from what you've said I think you're right in your conclusion  I take it it's not in warranty still? Don't Celestron have a big base in the UK?

I'm glad it hasn't put you off, I had one for a year a while ago and would definately buy another in future. Great scopes when working right. 

[PhotoGav]

I bought it second hand about a year and a half ago, so no warranty and the shop that I bought it from shut down about six months ago anyway! No, not ideal, but sometimes these things happen... I don't think Celestron have more than distribution centres in this country.

As for not being put off - astrophotography is one incident after another, constantly battling to get any subs at all, not to mention the weather here in the UK! If I were a normal person I would have been put off ages ago. However, when it works the results are so astounding that I am completely addicted to it. I am now striving for perfection ever more with each new project. Unfortunately this scope is not up to the job for me, so it must be euthanised! Hopefully it will make a good cheap scope for somebody that doesn't want to use a reducer.

Thank you for your help.

[Chris]

If I didn't now have to find another 7.5K for stamp duty after the 1st of April for the house we're buying, I would have been very tempted to buy it from you for visual and planetary. I'm sure It will still fetch a reasonable price, probably similar to XLT models maybe?

What do you think? 

[PhotoGav]

Yes, it isn't too bad really. I've managed some half decent images with it without the reducer. I will probably put it up for about £400, I think that is a bargain yet representative price.

Good luck with the house purchase and move. Somewhere suitably dark I hope!

[PhotoGav]

Humpf, I've just read this thread: 

It's made me think that perhaps the problem is with the reducer after all... More testing required before my Edge receives the lethal dose...

[Chris]

12 minutes ago, PhotoGav said:

It's made me think that perhaps the problem is with the reducer after all... More testing required before my Edge receives the lethal dose...

Your comment here also made me re-question things:

38 minutes ago, PhotoGav said:

Yes, it isn't too bad really. I've managed some half decent images with it without the reducer. 

 

39 minutes ago, PhotoGav said:

Good luck with the house purchase and move. Somewhere suitably dark I hope!

Thanks, It's right on the edge of town with open countryside to the south. I think it will be darker than our current in town location, so it should be good

[Chris]

Definately hold off the lethal dose for now. Worth trying another .7 reducer if you can.

[PhotoGav]

42 minutes ago, Chris Lock said:

Definately hold off the lethal dose for now. Worth trying another .7 reducer if you can.

That's my plan. Fingers crossed!

[pyrasanth]

I extensively use the Edge HD optics.  I know that there is a far greater attention to detail with regard to assembling & collimating these optics.

David Hinds advise that the only Celestron authorised source for testing & evaluation is to send the OTA back to Celestron in the USA. It is possible that the lens assembly in the baffle is the problem as if the OTA has taken a knock they might have come out of alignment so a focal reducer change might not correct the issue. This is such a shame as the images can be outstanding and are potentially so good I'm moving up to a 14" within the next few months.

I hope you get the issue sorted as there is nothing more irritating than a problem that frustrates you at every turn and I agree the British weather sucks at the moment.

[gorann]

Have you tried rotating the reducer in relation to the scope? I would presume that if the eggy stars are caused by the reducer then they would rotate with the reducer. I assume you know that you need to have the camera within a mm or less of the ideal focal plane given in the manual.

[Uplooker]

Hi,

currently on my phone, so not able to see all info and peoples locations etc. properly but have tried contacting Steve Collingwood at SC Telescopes, sure he would be able help / advise. Certainly a lot cheaper than shipping to and from Celestron

http://sctelescopes.com/about/

[PhotoGav]

At last, a story with a happy ending...

I tried a new reducer last night (thank you FLO for being wonderfully understanding and second to none with your customer service) and here is the result:

I think you will agree that it looks far more like it should and I am now going to close the case on 'PhotoGav vs Dodgy Edge Stars'.

Phew!