123 replies to this topic

[TCW]

The utility lights.

[clamchip]

I'm still working on a way to reduce power when observing with the C14. Ideally a 70mm eye piece would be great which would be 56X. But I'm worried about buying an expensive eye piece and seeing the shadow of the secondary in the field of view. I know you can have this problem if you try and go too low power. I doubt anyone sells a 70mm anyway.

None of my attempts so far have been very satisfactory, the tele-compressors (f6.3 and f3.3 focal reducers), camera lenses, copy machine lenses, etc.

This eye piece in the photo came with my Fecker and I don't have any idea what it is but it appears to be only one element, or at the most 2 elements cemented together, it does not have a 2nd group of elements or element, or  field lens. It has over an  inch eye-relief and I would say it cuts the power of the C14 to around 70X because my 40mm is 98X.

The element is contained in a brass cell with 'B171964' stamped into it, and that cell screws into the 1.25" aluminum barrel which fits our standard focusers.

Anyone have any experience using the C14 at low power?  or what the eye piece that came with my Fecker is all about?

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Edited by actionhac, 20 September 2014 - 06:53 PM.

[PiSigma]

Celestron made a 2" 70mm Kellner back in the day. Good luck finding one though.

[clamchip]

Thats what I need.

I wonder if it was from the Blue and White era or if it was meant for the C14.

I did a quick search and I think your right Jon a pretty rare eye piece.

 

Robert

[PiSigma]

There are a couple of old sales on AM. Definitely from the C-14 era.

[TCW]

In my orange tube C14 manual, Celestron lists 70, 60, 50, 40 and 32 mm eyepieces.

[CHASLX200]

Too bad they don't make a 70mm Ethos. You can pretty much forget wide field low power work with a C14. My C14 lived at around 450 to 800x most of the time i had mine and it was pretty **** when it came to the optics.

 

Chas

Edited by CHASLX200, 21 September 2014 - 08:43 AM.

[John Higbee]

Just bought a Russell Optics 72mm "super Plossl"...will let you know how it and the C14 get along once I have it.

 

John

[clamchip]

Thanks John.  Russell Optics looks great to me too so I just ordered one! thank you!

 

Robert

[clamchip]

The 72mm eyepiece is perfect John again thanks. It is 54X and nice and sharp. It came today and I  immediately tried it out. Its a  sunny day  and the C14 is great, very sharp focus. I normally can't focus on a day like today the C14 has too much power. The 72mm throttles the scope down nicely. A little like going grocery shopping in a top fuel dragster. 

 

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[De Lorme]

Here's a site{ http://www.asterism....als/tut14-1.htm} that really made collimating my new{to me}C14"XLT easy.

 

What about using a Russell 56mm instead of the 72mm?  Are these super plossl 55 degree eyepieces? Thanks De Lorme

[clamchip]

That a neat collimating guide, thanks.

The 56mm will give you 70X in the C14 and that would be a nice power. 40mm was my lowest which is 98X, and now I have the 72mm which is 54X and probably the lowest power practical with the C14.

I wanted a low power for  nights when the seeing is not the greatest, and also so I can make some distance between me and my subject, its difficult for me getting use to the C14's 154 inch focal length.

Here is Russel Optics and eyepiece specs:

http://www.russell-optics.com/

 

Robert

[De Lorme]

Robert, I'm so glad I ran into that web site. Following the simple instructions{in very small increments}and I was done in about 45 minutes.

I'm going with the 56mm.  Thanks for the web site.  De Lorme

[John Higbee]

Robert - great to hear that the 72mm is working so well for you...I just came back from a weekend trip and mine had arrived...unfortunately, the clear skies had departed!

 

How did it do under the stars?

 

John

[clamchip]

I have not had a chance to try the new 72mm under the stars. Its a great eyepiece and passed all my usual daytime tests but of course the stars are the what separate the men from the boys.

 

Robert

[bob midiri]

I have not had a chance to try the new 72mm under the stars. Its a great eyepiece and passed all my usual daytime tests but of course the stars are the what separate the men from the boys.

 

Robert

good timing on this, as I was just looking at this russell 65mm XL SP eyepiece.  http://www.ebay.com/...nts. thanks bob

Edited by bob midiri, 29 September 2014 - 09:09 AM.

[nexstar11]

 

 

I have the big orange Celestron drive corrector with a orange hand box. The drive works but I don't' think the slew works. When I get a chance I am going to take the base apart and see why.

 

I'd like to see some pics of this thing.  Assuming this is the heavy duty one from Sidereal Electronics?

 

Will do. It says Celestron on it but I will check the label.

 

Yes the pictures you posted were the HD dual axis drive corrector from Sidereal Electronics.   I have a black one exactly like that.  Hoping it's a loose wire and not another component. 

[clamchip]

I still have not been able to try out the new 72mm eyepiece under the stars, its been very foggy here.

Look at these images taken with a C14 of our moon:

http://www.damianpeach.com/lunar.htm

Isn't that amazing, wow.

 

Robert

[John Higbee]

Robert - I am planning to try my 72mm out on the C14 tonight.  Here in Northern VA, we're seeing the tail end of the big nor'easter that spun up yesterday off the Virginia Capes...high winds all last night, and high winds through this afternoon (gusting to 45), but the clouds are breaking up! 

 

Seeing will probably be mediocre (a lot of "boiling") but transparency should be good...not bad conditions for first lighting that eyepiece.

 

I mentioned before that my C14 came without the two 3 pound chrome OTA counterweights...and I've been looking for them without success for the last 8 months. So, I decided to improvise.  Meade still sells the old style OTA counterweights - five pounds, vice three, and in standard black, vice chrome.   The only problem is that the hole through the counterweight is 13/16" - the C14 bar comes in at 3/8".  I used some clear plastic tubing from the local hardware store (a piece of 3/8" ID, 1/2" OD, inserted into a piece of 1/2" ID, 3/4" OD), to rightsize the OTA hole (picture below). 

 

It works like a champ...the weight slides easily (with slight resistance) on the C14 bar, and the weight setscrew works great compressing the plastic tubing to get a secure grip on the OTA bar.

 

all the best, John

[bob midiri]

John did you have a chance to try this eyepiece the other night? What is the AFOV with these? How did the stars look..Im looking at this one or the 65mm XL super plossl. I just sent a question to Gary Russell about the AFOV of the 65mm. Bob

[John Higbee]

Bob - I did get to first light the 72mm Russell Super Plossl earlier this week.  I was pleased with the view...stars were pinpoints pretty much across the whole field (might have gotten a bit soft at the extreme edge of the field, but not really noticeable).  

 

What was really noticeable was the LONG eye relief...around 2"!  If you've got significant ambient light (street/porchlights etc) at your observing site, you might want to block it since it would be peripherally visible...I didn't have that, since I'm observing off a second story deck in my back yard (well screened by trees).

 

Found several interesting comments on the Australian "Ice in Space" site re: the Russell long focal length eyepieces (quotes follow):

 

"Gosh! The eyerelief is extraordinary! I had to pull my head back from the EP (note: he's talking about the 65mm here) a full inch to be able to see the whole FOV. This only got longer with the others, about 50mm for the 72, and a full 3" to use the 85mm."

 

"The True Field of View (TFOV)was the same in all Russell eyepieces. That is, the same amount of sky was seen, no larger or smaller. This is due to the limitation of the 2" barrel. This is what I meant to say when I mention AFOV. The TFOV visible in all of these is essentially the same as that given by a 40mm 68deg eyepiece.

The Apparent Field of View (AFOV) as a result gets smaller as the focal length increases. All of these eyepieces have a field stop of 43mm. The AFOV of the 65mm is approximately 38deg. This gets smaller with the 72mm and smaller again with the 85mm. The AFOV of the 72mm is 34.2deg, and that of the 85mm is only 29deg."

 

I like the 72mm, and will continue to use it...but if I were to get a "do-over", I'd go with the Russell 65mm - 25mm eye relief and wider AFOV would more than compensate for the slightly higher power (60x for the 65mm, vice 54X for the 72m (this calculated for the 3911mm focal length of our C14s).

 

Hope this helps...all the best, John

[bob midiri]

Thanks John, ive been in contact w Gary Russell...decided on a 65mm Koenig that he was experimenting with. It will be here Monday. It has a slightly wider AFOV then the 65mm XL plossl, with LESS eye relief...which is what I wanted. Ill interested in its performance when Im off the following week. Thanks for cluing me in on Russell eyepieces. bob

[Terra Nova]

Russell eyepieces are really nice. I have a couple of his 2" wide fields. And Gary is a super nice guy.

[bremms]

For me any EP over about 55mm just has a narrow FOV. A 40mm 68 degree has the same TFOV, a darker background, less sensitive to eye aberrations, does show the off axis coma and field curvature more though.