Tak TOEs 👉 Jupiter 🥂

[mikeDnight]

On 28/09/2021 at 22:48, JeremyS said:

I don’t look at the Moon 😳

Maybe you should invest in a goto mount Jeremy. 😂

[Andrew_B]

2 hours ago, mikeDnight said:

Maybe you should invest in a goto mount Jeremy. 😂

Either that or overcome his fear of becoming a werewolf. 😛

[Deadlake]

Managed to get some clear skies tonight so went out with BBHS T2 diagonal and TOE 4 mm to compare with Baader 2" max star bright diagonal.

My LZOS 130/F6 does not have enough back focus. I'll  need to get a StarLight extension for the focuser so I can use the T2 BBHS mirror diagonal or something is wrong with the T2 BBHS mirror diagonal, it’s optical path length is between the T2 prism and 2” prism?

T2 prism 38 mm

T2 mirror 48 mm

2 " Baader mirror 112 mm.

Very surprised about that as it's usually running out of in-focus which is the problem.

Not a total loss, Jupiter did look great thru the TOE 4 mm, saw a lot more belts that previous nights, rich details and colour.

Hopefully I'll be able to compare some other night.

Edited October 2, 2021 by Deadlake

[Highburymark]

On 28/09/2021 at 21:43, JeremyS said:

I had similar thoughts about the Q with my TSA 120. Since I got the Q, I’ve actually left it installed all the time. Which means I’m not us using my shorter FL eyepieces.

The Q is transparent, I.e you don’t notice it’s there. And it’s very comfortable to use

It also works well with my Zeiss binoviewer. And the 2-inch BBHS

Jeremy - is it the 1.5x ED extender you have for the TSA rather than the Q 1.6x? I’d be interested to hear if there are any issues reaching focus with extender/TSA 120, either with or without BVs? I’ve got an ED 1.5x on order too - will mean I can use 25mm Zeiss OPMI microscope eyepieces on planets and the Moon, and double stars in single ep mode.

[Highburymark]

15 hours ago, Deadlake said:

Managed to get some clear skies tonight so went out with BBHS T2 diagonal and TOE 4 mm to compare with Baader 2" max star bright diagonal.

My LZOS 130/F6 does not have enough back focus. I'll  need to get a StarLight extension for the focuser so I can use the T2 BBHS mirror diagonal or something is wrong with the T2 BBHS mirror diagonal, it’s optical path length is between the T2 prism and 2” prism?

T2 prism 38 mm

T2 mirror 48 mm

2 " Baader mirror 112 mm.

Very surprised about that as it's usually running out of in-focus which is the problem.

Not a total loss, Jupiter did look great thru the TOE 4 mm, saw a lot more belts that previous nights, rich details and colour.

Hopefully I'll be able to compare some other night.

Those light paths look right. Does sound like you need more out-focus. With T2 diagonals, easy option is to use Baader T2 spacers to find focus - either before or after the diagonal.

[JeremyS]

42 minutes ago, Highburymark said:

Jeremy - is it the 1.5x ED extender you have for the TSA rather than the Q 1.6x? I’d be interested to hear if there are any issues reaching focus with extender/TSA 120, either with or without BVs? I’ve got an ED 1.5x on order too - will mean I can use 25mm Zeiss OPMI microscope eyepieces on planets and the Moon, and double stars in single ep mode.

Yes, I use the Tak extender ED x 1.5, Mark. This one: https://www.firstlightoptics.com/takahashi-extenders/tak_tka37595.html

Ive had no issues with reaching focus with it and my 2-inch BBHS mirror diagonal. I also have no issues with my Zeiss binoviewer + 1.7x GPC + Baader 1.25-inch mirror diagonal (not tried with the 2-inch)

[Deadlake]

1 hour ago, Highburymark said:

Those light paths look right. Does sound like you need more out-focus. With T2 diagonals, easy option is to use Baader T2 spacers to find focus - either before or after the diagonal.

I have 5 mm spacers around will give those a go. Also will try out in my SD103S, now I can side-by-side mount...

[Highburymark]

38 minutes ago, JeremyS said:

Yes, I use the Tak extender ED x 1.5, Mark. This one: https://www.firstlightoptics.com/takahashi-extenders/tak_tka37595.html

Ive had no issues with reaching focus with it and my 2-inch BBHS mirror diagonal. I also have no issues with my Zeiss binoviewer + 1.7x GPC + Baader 1.25-inch mirror diagonal (not tried with the 2-inch)

Excellent - thanks. I’m thinking it will probably work nicely with other non-Tak refractors too? I have a little TV85 that I’ll experiment with. Great that it doesn’t add to eyepiece stacks. F/11.25 TSA sounds like fun!

[JeremyS]

31 minutes ago, Highburymark said:

Excellent - thanks. I’m thinking it will probably work nicely with other non-Tak refractors too? I have a little TV85 that I’ll experiment with. Great that it doesn’t add to eyepiece stacks. F/11.25 TSA sounds like fun!

I’ve read that ppl do use the Tak reducers with other makes. Worth a try. Interesting that the Tak reducers are advertised as being specific for some models. For example, they recommend a different reducer for my FC 100DZ than for my TSA 120. I have both, one for each scope. Sometime I will get around to doing  a swap test.

[Deadlake]

There is a CN thread on this:

https://www.cloudynights.com/topic/691274-takahashi-extender-ed-15x-on-non-takahashi-refractors/

I'll wait for next planet season and then try one out...

Jupiter starts getting obscured by roof tops at around 11:30 pm and seeing is best around mid night...

This quote got me having high hopes for my 130/F6

I use the 1.5x extender regularly on my FSQ-85EDX and TSA-120 and it works perfectly. More recently I tried it out on my A-P 130GTX and to my astonishment the views of Jupiter and Saturn were nothing short of spectacular.

Edited October 2, 2021 by Deadlake

[Stu]

1 hour ago, JeremyS said:

Yes, I use the Tak extender ED x 1.5, Mark. This one: https://www.firstlightoptics.com/takahashi-extenders/tak_tka37595.html

Ive had no issues with reaching focus with it and my 2-inch BBHS mirror diagonal. I also have no issues with my Zeiss binoviewer + 1.7x GPC + Baader 1.25-inch mirror diagonal (not tried with the 2-inch)

Without wishing to sound totally ignorant, what is the difference between this and, a barlow? I get that it’s only x1.5 vs the normal x2, but does it correct for anything else? I have a Zeiss Abbé barlow, and also an AP Barcon which I can remove the element from to get less that x2.

[Deadlake]

18 minutes ago, Stu said:

Without wishing to sound totally ignorant, what is the difference between this and, a barlow? I get that it’s only x1.5 vs the normal x2, but does it correct for anything else? I have a Zeiss Abbé barlow, and also an AP Barcon which I can remove the element from to get less that x2.

Extenders are Telecentric:

• No change in eye relief
• Can be placed any where in the optical chain

Barlows are usually two negative lens, whereas extenders have 2 negative and 2 positive lens.
Barlows will modify the focal plane, extenders will not.

Another example would be something like this:

https://astrograph.net/epages/www_astrograph_net.sf/en_GB/?ObjectPath=/Shops/www_astrograph_net/Products/AGAPMCTEL2

It's a good question as there are other alternatives to a Q extender...

 

Edited October 2, 2021 by Deadlake

[Stu]

21 minutes ago, Deadlake said:

Extenders are Telecentric:

• No change in eye relief
• Can be placed any where in the optical chain

Barlows are usually two negative lens, whereas extenders have 2 negative and 2 positive lens.
Barlows will modify the focal plane, extenders will not.

Another example would be something like this:

https://astrograph.net/epages/www_astrograph_net.sf/en_GB/?ObjectPath=/Shops/www_astrograph_net/Products/AGAPMCTEL2

It's a good question as there are other alternatives to a Q extender...

 

Thanks. Yes, well aware of difference between barlow and telecentric. Much like a Powermate then.

[Highburymark]

1 hour ago, Stu said:

Without wishing to sound totally ignorant, what is the difference between this and, a barlow? I get that it’s only x1.5 vs the normal x2, but does it correct for anything else? I have a Zeiss Abbé barlow, and also an AP Barcon which I can remove the element from to get less that x2.

My only criticism of the excellent Barcon is its (grrr - why does spellchecker always want to change this to it’s?!!!!) limited power when used after the diagonal - think it’s around 1.65x. Using it with 25mm eyepiece to try and get up to much higher powers requires a huge stack. The Zeiss Abbé is better in this regard. The newer AP Baradv has a bit more punch than its predecessor too. 

[Deadlake]

1 hour ago, Stu said:

Thanks. Yes, well aware of difference between barlow and telecentric. Much like a Powermate then.

Q extender can go telescope side of diagonal, but cannot see any other difference.

[JeremyS]

1 hour ago, Deadlake said:

Q extender can go telescope side of diagonal, but cannot see any other difference.

Nice shiny blue box with the Tak

[Deadlake]

46 minutes ago, JeremyS said:

Nice shiny blue box with the Tak

Yep, nothin like new Takahashi kit. 

[Andrew_B]

8 hours ago, Stu said:

Thanks. Yes, well aware of difference between barlow and telecentric. Much like a Powermate then.

The dedicated extenders also designed for use with specific telescopes which could allow for greater optimisation of the design.

In the case of the 1.7x extenders for the FS-60CB/FC-76DCU and FOA-60 they have the advantage of having a fixed position relative to the objective so they turn the scope into a true quadruplet or sextuplet design and should be capable of even better performance.

[Deadlake]

On 02/10/2021 at 16:01, JeremyS said:

Yes, I use the Tak extender ED x 1.5, Mark. This one: https://www.firstlightoptics.com/takahashi-extenders/tak_tka37595.html

Ive had no issues with reaching focus with it and my 2-inch BBHS mirror diagonal. I also have no issues with my Zeiss binoviewer + 1.7x GPC + Baader 1.25-inch mirror diagonal (not tried with the 2-inch)

Out looking a Jupiter with 5 mm spacer, image is better with BBHS mirror diagonal then the prism flavour. TOE 4 mm is really performing as is HR 3.4 mm. Both show belts and various shades of red tonight. Seeing is 3.5 out of 5 otherwise I’d of tried a HR 2.4 mm.

Edited October 4, 2021 by Deadlake

[Highburymark]

17 minutes ago, Deadlake said:

Out looking a Jupiter with 5 mm spacer, image is better with BBHS mirror diagonal then the prism flavour. TOE 4 mm is really performing as is HR 3.4 mm. Both show belts and various shades of red tonight. Seeing is 3.5 out of 5 otherwise I’d of tried a HE 2.4 mm.

I really like the BBHS mirror too. My T2 Zeiss prism usually lives on the TV85 for solar work - haven’t had chance to test it with the TSA yet. Makes sense that you’re getting better results with the mirror because your scope is relatively fast. With my F/7.5, I’m not expecting any noticeable differences between the two diagonals, but we shall see.
I’ve ordered a TOE 4 to replace my Delite 4, and complete the mini set.

[Deadlake]

12 minutes ago, Highburymark said:

I really like the BBHS mirror too. My T2 Zeiss prism usually lives on the TV85 for solar work - haven’t had chance to test it with the TSA yet. Makes sense that you’re getting better results with the mirror because your scope is relatively fast. With my F/7.5, I’m not expecting any noticeable differences between the two diagonals, but we shall see.
I’ve ordered a TOE 4 to replace my Delite 4, and complete the mini set.

A tele centric extension would be the next and final step. I suspect apart from the moon my othe HR’s will not be used…

[mikeDnight]

18 minutes ago, Deadlake said:

A tele centric extension would be the next and final step. I suspect apart from the moon my othe HR’s will not be used…

I wouldn't write them off just yet. They are absoloutly exquisite for studying binary stars. Some time ago while testing out my DZ I barlowed my 1.6mm HR. That gave me a rediculous 1000X magnification. The star image was so perfect and the HR so comfortable to use, (the mount was a driven EQ), that I repeatedly kept checking I was using the 1.6mm because I couldn't believe the view could have possibly been so good. Of course it's challenging to centre a star at 1000X, but for me it was well worth the effort. Still using the 1.6mm but removing the barlow gave me 500X, which was a much easier power to use, yet with just as much of a wow factor.

[JAC51]

On 02/10/2021 at 19:32, Highburymark said:

My only criticism of the excellent Barcon is its (grrr - why does spellchecker always want to change this to it’s?!!!!) limited power when used after the diagonal - think it’s around 1.65x. Using it with 25mm eyepiece to try and get up to much higher powers requires a huge stack. The Zeiss Abbé is better in this regard. The newer AP Baradv has a bit more punch than its predecessor too. 

I have it's successor the Baradv and with it being a long focal length barlow (about 100mm )your right  about the length of the stack behind it. AP quote the optimum range of the Baradv as being between x1.8 and x2.5. With the standard extension that came with it, some 75mm, I'm indeed getting a measured x1.8 or so . I guess very sensibly AP give the minimum tube length needed as its easier to add an extension to get to x2 and x2.5 the cut down the one you have.

Meanwhile I  can get you x1.65 figure by putting a Morpheus 9mm into the Baradv 75mm extension in 2" mode. With the field stop now below  the 2" shoulder of the Morpheus the mag of the barlow is down to x1.65 as said.

 

[Highburymark]

3 hours ago, JAC51 said:

I have it's successor the Baradv and with it being a long focal length barlow (about 100mm )your right  about the length of the stack behind it. AP quote the optimum range of the Baradv as being between x1.8 and x2.5.

 

Useful to know optimum range from AP - didn’t know that. They certainly perform well above that power too - at least to my not perfect eyes.

[Andrew_B]

On 02/10/2021 at 17:24, JeremyS said:

I’ve read that ppl do use the Tak reducers with other makes. Worth a try. Interesting that the Tak reducers are advertised as being specific for some models. For example, they recommend a different reducer for my FC 100DZ than for my TSA 120. I have both, one for each scope. Sometime I will get around to doing  a swap test.

From what I remember Jeremy, extenders and flatteners are less fussy about which scope you pair them with, but reducers are best if they're matched for the particular scope they're going to be paired wit, while other combinations can perform noticeably worse.

I haven't been able to test it personally but I've seen it mentioned and I notice that on Astrograph they advise that the reducers they sell are designed to operate with specific telescopes and are not interchangeable unless another scope falls within the tolerances of that model. Takahashi have a multi-flattener that works with all current FS and FC models (and many older ones apparently), but the FS-60 has its own reducer and there's a separate one for the FC-76 and FC-100 models so presumably the focal ratio of the 60mm (f5.9) compared to the larger scopes (f7.4 and slower) is what makes the difference.