How do I interpret Takahashi diagrams?

[Deadlake]

9 hours ago, jetstream said:

I think that f6 or 7 with the 50mm ?plossl with be fine for f3 or 4 equivalent.  I look forward to showing people the views with one- theres no chance a first time observer will see Barnards Loop without it for example.

There is the Losmandy AZ mount too, but it looks very precisely made with slow mo controls- guaranteed not to work in the cold.Even the diag holder threads tighten up too much, some wont work.

Best results for NV, F6 is upper limit. With the Televue compresssor will get you to F2.4,  hence the use of an FSQ-106 which will be around F2. Popularity of Boren-Simon newts is local F and flat field, but yes multi use is hard to do.

Edited February 17, 2021 by Deadlake

[Deadlake]

9 hours ago, JeremyS said:

Of those 3, I’d go for the FC 100 DZ. that’s what I did in the end.

Not sure about lightweight mount. The ScopeTech on Berlebach Report is very light, but the DZ is on the high side for it.

Deadlake mentions a lighter mount for the TSA120. I sometimes put mine on a WO EZTouch (no longer made) on Berlebach Planet. The mount and tripod are grab and go: UNI 28 would be more so. 

I think they where by ayo, still available

http://www.aokswiss.ch/ayo/main_ayo.html

when back in stock I’ll get one of these

https://global.vixen.co.jp/en/product/25164_3

As much as I like wood it’s a lot lighter and passes the nudge test.

[mikeDnight]

I spent an hour looking at stars and a few fuzzies with my DZ after the clouds cleared last night, and the need to understand Takahashi diagrams suddenly became unimportant. The seeing was ok but certainly not steady, and there was a haziness all around.   M42 was dropping low behind the tree line towards my south west, yet the E star was instantly obvious with the scope straight out of the house. I couldn't make out the F star, but the trees were in the way. The soot black nebulosity in M42 stood out solidly against the brighter nebula.   It was a glorious sight made all the more impressive given the poor position of Orion.   I played around with various eyepieces for a while, enjoying the views of rich star fields and open clusters.   The Pleiades,  despite being low was still enmeshed in subtle nebulosity.  But the most pleasurable and memorable part of the evening were the stars themselves. Despite the less than perfect seeing the star images were simply exquisite,  and the little DZ with a 2mm Vixen HR eyepiece stood 400X with ease, it wasn't even breaking into a sweat, and still it gave textbook images.  I also found that eyepiece choice makes a real difference. The HR's are a perfect match with the DZ and double stars, and my old Ultrascopic's kept pace quite well in giving perfect star images. But quite surprisingly, my 10XW compared to my 10mm Ultrascopic, was not quite upto delivering the sharpest stars, even on axis. It is still a beautiful eyepiece though, but perhaps nolonger good enough!? So it seems you don't need to worry about graphs, you just need to look at the stars.

[JeremyS]

37 minutes ago, mikeDnight said:

I spent an hour looking at stars and a few fuzzies with my DZ after the clouds cleared last night, and the need to understand Takahashi diagrams suddenly became unimportant. The seeing was ok but certainly not steady, and there was a haziness all around.   M42 was dropping low behind the tree line towards my south west, yet the E star was instantly obvious with the scope straight out of the house. I couldn't make out the F star, but the trees were in the way. The soot black nebulosity in M42 stood out solidly against the brighter nebula.   It was a glorious sight made all the more impressive given the poor position of Orion.   I played around with various eyepieces for a while, enjoying the views of rich star fields and open clusters.   The Pleiades,  despite being low was still enmeshed in subtle nebulosity.  But the most pleasurable and memorable part of the evening were the stars themselves. Despite the less than perfect seeing the star images were simply exquisite,  and the little DZ with a 2mm Vixen HR eyepiece stood 400X with ease, it wasn't even breaking into a sweat, and still it gave textbook images.  I also found that eyepiece choice makes a real difference. The HR's are a perfect match with the DZ and double stars, and my old Ultrascopic's kept pace quite well in giving perfect star images. But quite surprisingly, my 10XW compared to my 10mm Ultrascopic, was not quite upto delivering the sharpest stars, even on axis. It is still a beautiful eyepiece though, but perhaps nolonger good enough!? So it seems you don't need to worry about graphs, you just need to look at the stars.

But what MTF did you use, Mike?

I’m sure we could do a fast Fourier transform on your impressions. 
 

🤣

[jetstream]

9 hours ago, Deadlake said:

I think they where by ayo, still available

I truly wish I could purchase from here to avoid the current shipping/import mess. Using the TSA120 last night for high power lunar only confirmed the need for a substantial mount for it.

It would be nice to get a crank up Berlebach, with enough mount to handle both the TSA120, the FC100DF and the Mewlon 180mm. This could be just a dream though...

I'm looking at Vixen mounts as well, possibly used ones.

[Deadlake]

10 minutes ago, jetstream said:

I truly wish I could purchase from here to avoid the current shipping/import mess. Using the TSA120 last night for high power lunar only confirmed the need for a substantial mount for it.

It would be nice to get a crank up Berlebach, with enough mount to handle both the TSA120, the FC100DF and the Mewlon 180mm. This could be just a dream though...

I'm looking at Vixen mounts as well, possibly used ones.

What sort of mount? I have an SXP2 but thats because I like it for tracking fast moving objects in the summer when the planets are high and large magnification. With my scope tech constantly twiddling the slow-mo's.

Why not the AZ100 as a mount, then you could have a Mewlon or Newt side by side with an APO?

Checkout the US CN thread, AZ100 seems to be arriving on those shores.

Forgot to mention I was checking out NV album on CN, Jeff has got some nice shoots with his 210 Mewlon.
 

Edited February 17, 2021 by Deadlake

[jetstream]

3 minutes ago, Deadlake said:

Why not the AZ100 as a mount,

There is a fine line between precision and function when it comes to working in the cold. The Rowan AZ100 looks superb- I wonder how those gears will work in the cold? Same for the Losmandy.

[andrew s]

3 hours ago, JeremyS said:

But what MTF did you use, Mike?

I’m sure we could do a fast Fourier transform on your impressions. 
 

🤣

Takahashi refractor owners tend to drone on so just a few low frequencies from the fft.

Regards Andrew 

Edited February 17, 2021 by andrew s

[johninderby]

Rowan uses Aeroshell 33 grease which is rated down to -54C and has adjustable gear mesh so should be no problem.

[Deadlake]

10 minutes ago, johninderby said:

Rowan uses Aeroshell 33 grease which is rated down to -54C and has adjustable gear mesh so should be no problem.

How often does it need to be greased up, once a year... 🤣 😀 😂

Edited February 17, 2021 by Deadlake

[johninderby]

4 minutes ago, Deadlake said:

How often does it ned to be greased up, once a year... 🤣 😀 😂

They do say every year or two.

Aeroshell 33 is expensive £££££ but great stuff. Is also known as airframe grease as used on jets. The sell big packs for various aircraft. 😁

Edited February 17, 2021 by johninderby

[jetstream]

3 minutes ago, johninderby said:

Rowan uses Aeroshell 33 grease which is rated down to -54C and has adjustable gear mesh so should be no problem.

This looks to be an extremely well made mount and good to know about the grease. Its the gears tightening up in the cold that is my concern, its a lot of money. Any North America vendors?

[Deadlake]

2 minutes ago, jetstream said:

This looks to be an extremely well made mount and good to know about the grease. Its the gears tightening up in the cold that is my concern, its a lot of money. Any North America vendors?

https://telescopes.net/store/rowan-astronomy-az100-altaz-mount-head.html

In stock...

 

[johninderby]

They ship to North America so no problem getting hold of one direct from Rowan or. FLO. You might ask Rowan. about any gear adjustments need for extreme cold. 

Or ask Dek Rowan Astro who is an SGL member.

Edited February 17, 2021 by johninderby

[jetstream]

39 minutes ago, johninderby said:

They ship to North America so no problem getting hold of one direct from Rowan or. FLO. You might ask Rowan. about any gear adjustments need for extreme cold. 

Or ask Dek Rowan Astro who is an SGL member.

Just talked to a CDN vendor who will talk to them, thanks.

[jetstream]

20 hours ago, Deadlake said:

In stock...

You runnin the Rowan?

[Deadlake]

10 minutes ago, jetstream said:

You runnin the Rowan?

No, however if I get a Newt/Mewlon for NV I'd get one. Also holding out to find out what the tracking upgrade is like. The AZ100 will track an object when electric motors are added. I would like that option.   I'd like to put an Observatory in the garden, with the SXP2 in there. Then use an AZ100 to be mobile around the garden avoiding trees in neighbours garden. I live in a conversation area, so chopping down a tree without a permit costs you £20000. Council tracks with street view etc...

Edited February 18, 2021 by Deadlake

[jetstream]

19 minutes ago, Deadlake said:

costs you £20000.

Seriously?

You have lots of trees there then? What is a conservation area in UK?

Nice mount btw that SXP2. I hauled the out the EQ6 assembled, counterweight, etc and all last night-got a new technique lol! Superb views- the Takahashi MTF was very high last night!!Excellent seeing.

I think the Rowan will give excellent Tak MTFs from the lack of shakes . Are Berlebachs that much better for steadiness than the steel tripod? What do you use?

 

[Deadlake]

6 minutes ago, jetstream said:

Seriously?

You have lots of trees there then? What is a conservation area in UK?

Nice mount btw that SXP2. I hauled the out the EQ6 assembled, counterweight, etc and all last night-got a new technique lol! Superb views- the Takahashi MTF was very high last night!!Excellent seeing.

I think the Rowan will give excellent Tak MTFs from the lack of shakes . Are Berlebachs that much better for steadiness than the steel tripod? What do you use?

 

When we moved in had some dead trees taken out, needed a permit from the council per tree. 

Conversation area, very strict on planning laws, removing trees etc. I live in the South Downs, area of outstanding nature beauty and not far from Dark Sky preserve. 

Do you find your EQ6 loud, SXP2 has belt drives, so very quite.

Berlebachs are good, tempted, however my brain says carbon to cut down on weight. Berlebachs is 7 kg, Vixen carbon is 2.5 kg. Depends how much you are moving it, no idea of temperatures effect, another consideration. Both pass the nudge test. I have an aluminium HAL tripod, but will change once carbon tripods are back in stock.

[Cornelius Varley]

13 minutes ago, jetstream said:

What is a conservation area in UK?

Most towns in the UK will have a conservation area. Any new builds in that area have to maintain the look and style of the existing buildings (you can't fit uPVC windows to an 800 year old cottage). Trees in conservation areas (and elsewhere) have TPOs (Tree Preservation Orders) which means that the tree can only be felled under exceptional circumstances ie the tree is causing structural damage to a nearby property or is diseased. A diseased tree can be removed but has to be replaced with a similar specimen. Unauthorised removal of a tree can land you with a £20000 fine

[jetstream]

1 minute ago, Deadlake said:

Do you find your EQ6 loud, SXP2 has belt drives, so very quite.

Sounds vg there nice spot, no idea where it is though maybe I'll look it up.

I havn't used the AZEQ6 much.., but yes its kinda loud. Carbon fibre- I'll check then out.

[Deadlake]

10 minutes ago, jetstream said:

Sounds vg there nice spot, no idea where it is though maybe I'll look it up.

I havn't used the AZEQ6 much.., but yes its kinda loud. Carbon fibre- I'll check then out.

In AZ100 thread here:
 

And CN

https://www.cloudynights.com/topic/708353-rowan-astronomy-az100-arrived/?p=10393748

Would lookalike a very good setup for visual usage...

Dark sky site is around 30 mins from my house, I'd hope to find one closer.

https://www.darksky.org/our-work/conservation/idsp/reserves/southdowns/

 

Edited February 18, 2021 by Deadlake

[KP82]

The Rowan AZ100 + encoders + tracking/GOTO motors are going to be the ultimate heavy duty alt-az mount. The only downside could be its cost, probably going to be close to £3k.

Edited February 18, 2021 by KP82

[Deadlake]

5 minutes ago, KP82 said:

The Rowan AZ100 + encoders + tracking/GOTO motors are going to be the ultimate heavy duty alt-az mount. The only downside could be its cost, probably going to be close to £3k.

Does anyone have an idea of specs, or all in flux at the moment?

I don't know of a similar product.

Edited February 18, 2021 by Deadlake

[Sunshine]

On 14/02/2021 at 18:58, JeremyS said:

Interesting, John. There are a few owners of TSA 102’s on here that could try. 

Challenge accepted! soon as the weather clears, only issue is this pair at its highest will be fairly low in the SW sky from my location, leaving it directly over a major metropolitan centre from my vantage point.