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Monster in the making

John

By John
in Discussions - Eyepieces

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John

John

Posted
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The photo below has been posted on another forum. It's apparently a new 3 inch eyepiece that is under development, possibly by Explore Scientific. I don't know the focal length but I'd guess somewhere in the 50mm - 80mm range. It is intended for use in large aperture SCT's I believe. The likely price is reported to be in the $1,200 - $1,500 range but more shockingly it's weight is thought to be in the region of 10 lbs :shocked:

In the photo for scale are a 2" eyepiece and a 1.25". Truly a monster in the making !

post-118-0-04654100-1352334912_thumb.jpg

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alan potts

alan potts

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Wow,

I have a 55mm TV Plossl which is not that heavy. I dropped it a couple of years back and just put my foot out to stop it hitting concrete directly. I stopped it but it still got a dent on the edge of eyecap rubber top part, still the glass is fine. Now try that with this, broken foot and a dent in the concrete I think.

Alan

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DirkSteele

DirkSteele

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Who do you think they copied on this one, maybe that 4 inch Zeiss monster that was on a thread a few weeks back.

Possible they are cloning Siebert Optics. They have been manufacturing 3 and 4" EPs for professional observatories and larger amateur scopes for some time.

http://www.siebertoptics.com/SiebertOptics-eyepieces-observatory.html

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John

John

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Apparently it is indeed an Explore Scientific 30mm 100° ep. What a monster!!

I missed that Damo. Not as long as I'd thought then. The diagonal is going to be a whopper too though - this guy has made his own 3" diagonal and look at the 31mm Nagler for scale !:

post-118-0-50230000-1352368953_thumb.jpg

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DirkSteele

DirkSteele

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Apparently it is indeed an Explore Scientific 30mm 100° ep. What a monster!!

If that is true I am getting rather excited. Might well become the only non Televue EP in my collection but I am already thinking about what it might do for me with my 7 inch triplet f/7 Apo that I am taking delivery of in February.....2.4 degree field of view. Exciting. And less issues with balance given all the weight with the Apo is up the front.

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Damo636

Damo636

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I missed that Damo. Not as long as I'd thought then. The diagonal is going to be a whopper too though - this guy has made his own 3" diagonal and look at the 31mm Nagler for scale !:

Thats just unreal John, it would take one hell of a focuser to support that lot!!

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John

John

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If that is true I am getting rather excited. Might well become the only non Televue EP in my collection but I am already thinking about what it might do for me with my 7 inch triplet f/7 Apo that I am taking delivery of in February.....2.4 degree field of view. Exciting. And less issues with balance given all the weight with the Apo is up the front.

A 3" eyepiece with a 3" diagonal could weigh around 15llbs or more - thats a lot of counterbalance to the objective end !

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E621Keith

E621Keith

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John,

Who do you think they copied on this one, maybe that 4 inch Zeiss monster that was on a thread a few weeks back.

Alan.

I don't think they need to copy anyone. 25mm ES100 and 9mm ES120 were original designs as far as I know.

After making modified TV for so many years, JOC would have trained enough talented engineers to come up with their own designs. For a start, it's unlikely JOC could get the exact same glass used in TV eyepieces for their ES82 and ES100, so they need to modified TV's designs to match the glass accessible to JOC. In that process their engineers would have learnt a lot of eyepiece design and fabrication techniques necessary for coming up with something original. It's the same process the Japanese went through decades ago. Nikon used to make Zeiss and Leica clones, but look at it now.

Furthermore, TV make their eyepieces in Taiwan and some engineers at that factory may have been head hunted and now work for JOC.

There are several problem though,

1. There aren't that many scope with 3" focuser

2. Celestron and Meade use different visual back for their large SCT and most SCT are already back heavy, this can cause a balance issue.

3. 3" accessories are rare. I've never seen a 3" filter or a 3" coma corrector.

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DirkSteele

DirkSteele

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A 3" eyepiece with a 3" diagonal could weigh around 15llbs or more - thats a lot of counterbalance to the objective end !

Almost enough to allow the tube rings to be at the centre of the telescope tube, rather than near the objective! This is definitely going to be a development to watch. I assume that Explore Scientific will also manufacture a 3" diagonal to go with this bad boy.

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alan potts

alan potts

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I don't think they need to copy anyone. 25mm ES100 and 9mm ES120 were original designs as far as I know.

After making modified TV for so many years, JOC would have trained enough talented engineers to come up with their own designs. For a start, it's unlikely JOC could get the exact same glass used in TV eyepieces for their ES82 and ES100, so they need to modified TV's designs to match the glass accessible to JOC. In that process their engineers would have learnt a lot of eyepiece design and fabrication techniques necessary for coming up with something original. It's the same process the Japanese went through decades ago. Nikon used to make Zeiss and Leica clones, but look at it now.

Furthermore, TV make their eyepieces in Taiwan and some engineers at that factory may have been head hunted and now work for JOC.

There are several problem though,

1. There aren't that many scope with 3" focuser

2. Celestron and Meade use different visual back for their large SCT and most SCT are already back heavy, this can cause a balance issue.

3. 3" accessories are rare. I've never seen a 3" filter or a 3" coma corrector.

Keith,

Very good points you make and i can agree with them, I thought Televue were made in Japan though.

I guess the filters and such like, if you can afford the eyepiece and diagonal you can commission someone to make them.

I am sure my LX would not like 12-15 pounds on the back. I think it is enough with the two inch diagonal and a 41mm Pan. I use a counterweight system by ADM as well. I don't think the bearings would last long with 12 pounds of weight at the front and back.

Alan.

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E621Keith

E621Keith

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Keith,

Very good points you make and i can agree with them, I thought Televue were made in Japan though.

Televues are made in Japan and Taiwan and then shipped to US for QC and distribution. You can read about it here, in the Manufacture and Quality Control section.

http://www.televue.c..._page.asp?id=78

!!!

I wasn't aware there were 120* EPs!

Here is a CN thread talking about it. There are a few user reviews, including one in a F4 dob. Read from post #5444623

http://www.cloudynig.../fpart/all/vc/1

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