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Optolyth TBS 100 APO/HDF

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Old Saturday 21st April 2018, 18:58   #1
Bencw
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Optolyth TBS 100 APO/HDF

Hi all,
Can anyone tell me the focal length of the TBS 100 ? I did a search but can only find info on the TBS 80.

With thanks, Ben
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Old Saturday 21st April 2018, 21:14   #2
dipped
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630 mm according to this http://www.pt-ducks.com/ if this is the right or similar model TBG100. See 100mm test of scopes.
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Old Sunday 22nd April 2018, 11:57   #3
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Hi Dipped,
Many thanks for that and the link. Optolyth list the scope length at 400mm, but oddly they dont give the focal length. In the pt-ducks test they state scope length 495mm including the zoom eyepiece , the zoom eyepiece they used looks around 9mm long in the picture so that sounds about right.

Thanks, Ben
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Old Sunday 22nd April 2018, 13:40   #4
Tringa45
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Ben,
There's not a direct relationship between the physical length and the focal length of a scope. It all depends on the optical design. Significant differences between the two measurements can be found in telephoto camera lenses or reflecting telescopes for example.

John
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Old Sunday 22nd April 2018, 13:52   #5
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Thanks John,

I find it strange that Optolyth dont give the focal length on their website ad for these scopes, (unless i'm missing something, which is very possible) most others have the FL listed in the specification.

Ben
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Old Friday 27th April 2018, 15:31   #6
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Well I bought the Optolyth TBS 100 APO/HDF, pre-owned, but mint, together with a stay on cover, 30-60x 100 EP, and a 1.25" adapter all for 499, i'm clued up on binoculars, but not too familiar with used scope prices but it seemed an ok price? I had an old TBG 80 awhile back and sold it, someone here advised me not to be in a hurry to part with it and they were right, here I am back with Optolyth. I'm not overly keen on the Zoom EP, but managed to pick up a current model, used, fixed 45x EP, should arrive next week.
Thanks again for the info.

Last edited by Bencw : Friday 27th April 2018 at 18:36.
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Old Saturday 28th April 2018, 17:06   #7
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Bencw,

Since you have the astro adapter, and assuming your scope isn't too old and reach focus with 1.25" astro eps, you would gain to have the Baader Hyperion zoom. With this ep the resulting mags on the Optolyth 100 are 26-78x, the image quality results very good and with better AFOVs than the zooms from Optolyth...
I have complained to Optolyth that the 20-60x/100 zoom had almost the same TFOV from 20 to almost 30x, but the more recent 30-60x/100 zoom version doesn't make sense without having wide field of view...
The Optolyth 20/30x and the 30/45x fixed eps are better than their zooms but there are better astro alternatives for the same cost.
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Old Saturday 28th April 2018, 20:21   #8
Bencw
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Thank you David, I have read good things about the Baader, think the Baader Zoom will focus and work in my Optolyth 100 APO/HDF, using the adapter, I dont know how old it is, but think its not that old, I think they may possibly be still selling the same model new. Photo attached. It is just the length of the EP nose that might stop it fully engaging. I guess the best thing would be to take my Optolyth zoom to the shop and compare it, it will then be easy to see if it fits. Ben.

PS: Would you know the length of the Baader Hyperion Zoom nosepiece by any chance David?
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Old Saturday 28th April 2018, 22:23   #9
DRodrigues
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At http://www.pt-ducks.com/cr-telescope...r%20experience, you can see that it should focus if the serial number of your scope is higher than 126475 but will not focus if smaller than 125528. If within 2 serial numbers I can help if you take a photo of the eyepiece hole of the telescope, without the eps - the older version has a big ring inside reducing the diameter that is absent in the less old, so allowing the astro eps to get more inside and reach focus.
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Old Sunday 29th April 2018, 08:51   #10
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Ah, thanks David, it's the older one, the number is 123303, and I can see the ring you mention. Ok, will forget about the Baader and try fixed EPs.
So the Astro adapter is actually no good for this scope, probably the reason for sale.
Many thanks.

Last edited by Bencw : Sunday 29th April 2018 at 09:08.
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Old Sunday 29th April 2018, 10:30   #11
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That's a shame Ben, it's one of the reasons I sold my Optolyth. Although you can get the Baader to fit, I'm not sure if it will focus to true infinity.
What's the zoom like you have at the moment. Is it the 22x60 0r the newr 20x60?

Ron

Last edited by giosblue : Sunday 29th April 2018 at 11:39.
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Old Sunday 29th April 2018, 13:15   #12
Bencw
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Quote:
Originally Posted by giosblue View Post
That's a shame Ben, it's one of the reasons I sold my Optolyth. Although you can get the Baader to fit, I'm not sure if it will focus to true infinity.
What's the zoom like you have at the moment. Is it the 22x60 0r the newer 20x60?

Ron
Hi Ron,

The zoom is a newer one, 30x-60x -- x100, its better than the old 22-60x I had on my old TBG80, but I still find it not a great zoom, and as David pointed out, narrow FOV. One of the reasons I sold the old one was it wouldn't take a decent zoom, I thought all the later models would, and thought this one would. Still, its a good scope, better than my old one. The big retaining ring in the scope is roughly 15mm deep so may possibly be replaceable with a narrower ring, but even if thats possible, I still dont think it would leave enough depth for the nosepiece in order to focus to infinity.

Ben
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Old Sunday 6th May 2018, 21:42   #13
Bencw
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Quote:
Originally Posted by DRodrigues View Post
At http://www.pt-ducks.com/cr-telescope...r%20experience, you can see that it should focus if the serial number of your scope is higher than 126475 but will not focus if smaller than 125528. If within 2 serial numbers I can help if you take a photo of the eyepiece hole of the telescope, without the eps - the older version has a big ring inside reducing the diameter that is absent in the less old, so allowing the astro eps to get more inside and reach focus.
I have had a good look at the big retaining ring, it is only a fraction too tight for a 1.25" EP. It looks easily removable along with the small glass lens at the bottom, I know some one who could take 0.5mm off the inside diameter of the ring with a lathe to allow an astro EP to fit, but the drawback would be if this scope is gas filled?
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Old Monday 7th May 2018, 06:42   #14
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Ben, I don't think you would need to remove the glass protector. When I had my Optolyth TBS 80 it didn't touch the glass when the Baader was fitted. I'm using the Baader on my Pentax scopes at the moment, it's an excellent piece of kit. I’f you can get it to fit it would certainly be worthwhile.
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Old Monday 7th May 2018, 19:02   #15
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Originally Posted by giosblue View Post
Ben, I don't think you would need to remove the glass protector. When I had my Optolyth TBS 80 it didn't touch the glass when the Baader was fitted. I'm using the Baader on my Pentax scopes at the moment, it's an excellent piece of kit. If you can get it to fit it would certainly be worthwhile.
Hi Ron,
I didnt mean remove the glass permanently, but looking at it, I think it would have to come out to get the big retaining ring out, in the TBS 100 it looks like the round glass is fitted/threaded into the bottom of the of the big ring with a smaller retaining ring, it is differrent to my old TBG 80, I think that had a a sort of glass pane inside. That is why just taking out the ring and replacing it with a 1.25" ID 37mm 0.75 pitch is a non runner, the glass would not fit back into that. I think it would be an easy job for someone who knows how to use a lathe to take a fraction off the rings inner diameter down as far as the section that takes the glass, then the Baader would fit fine. I may give it a go, I dont know if this scope is nitrogen filled though or if it would really matter.
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Old Monday 7th May 2018, 19:54   #16
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What about removing 0.5mm from the eyepiece barrel?

I don't know if the Baader eyepiece lens elements fall out if dismantled, or if it has a separate barrel.
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Old Monday 7th May 2018, 23:18   #17
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Bencw,
In fact, eventually can be easier to reach focus with the Baader Zoom than with most astro-eps - if you remove the 1.25" adapter from the Baader it goes all inside the Optolyth body (just confirmed that), and most probably will reach focus - will confirm you that tomorrow. Unfortunately Baader doesn't produce an adapter ring for Optolyth scopes but it can be done with a CNC machine, even adapting the optolyth astro-adapter to the Baader Zoom thread...
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Old Tuesday 8th May 2018, 09:26   #18
Bencw
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Thanks David
Thank you David, this sounds promising, I have ordered 2 Baader hyperion zoom mark IV as I spotted two for sale at a very good price. If it does not work out with the scope, I will anyway use them in my 100mm semi APO binocular although they only have a focal length of 460mm so might not get the max out of the zoom. It will be good if it works in the Optolyth scope as that gives by far the best image.

Hi Binastro,
It seems from what David said the barrel will remove, but I dont really want to remove anything from the Baader barrel as I would also like to sometimes use it with my semi APO binocular or maksutov scope. I find the maksutov I have is not that good, but might possibly be improved with the Baader EP.
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Old Wednesday 9th May 2018, 00:10   #19
DRodrigues
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Ben,
The Baader zoom reached focus on the older Optolyth 100, with the Baader 1.25" adapter removed but even with the larger ring where it screws in. Since mine is the MK3 and yours the Mk4, you will get even more focus range. Now you have to find someone to do an adapter ring in a CNC machine... Good luck!
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Old Wednesday 9th May 2018, 09:26   #20
Bencw
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Quote:
Originally Posted by DRodrigues View Post
Ben,
The Baader zoom reached focus on the older Optolyth 100, with the Baader 1.25" adapter removed but even with the larger ring where it screws in. Since mine is the MK3 and yours the Mk4, you will get even more focus range. Now you have to find someone to do an adapter ring in a CNC machine... Good luck!
Hi David,
Many thanks, thats great news, I look forward to trying my Baader on my Optolyth scope.
Thank you very much for taking the trouble to test it, I am grateful.

Ben
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Old Wednesday 9th May 2018, 10:58   #21
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If you remove the 1.25in adapter the Baader Zoom should fit. It did on mine with an O ring to secure it. It worked really well. You can always put he adapter back on when you need to.
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