TSA120 on M51/M42

[jetstream]

In my eager dream to test the new 2.5mm XO, I set the TSA120 up for lunar and initiated the final cooling process. Not wanting to waste this observing time I set out to see a couple of favourites, M51 and M42.

Avg (-) transparency had the NELM around 5.9, not the best, but OK.

M51 was low during the cooldown time but it was in between the trees and so observable. I'm not sure how many have played round with smallish scopes on this object but the views can be very good. In these scopes its best (to me) to play around with the mags and try a bunch of different eyepieces.

The 24ES 68 found M51 manually and presented a nice very distinct set of galaxies, however experience told me there was much more in there. In goes the excellent 18BCO and some intermittent "mottling" appeared in the outermost of M51, knowing what this meant the 16T5 Nagler came out.

If you ever observe M51 as round with no spirals, but with intermittent streaks in the outer portion of it, you are actually seeing the spirals. These streaks can be seen as faint small mottling or in my case last night as distinct, faintish intermittent streaks. Magnification brings these out and usually around a 2mm exit pupil in small scopes works well.

A very fine view!

M42! What can I say! The Tak bought out a highly green core with massive wings espc on the one side and M43 showed a nice but small comma shape. The extensive glow of the Running Man was in your face and the whole thing was dazzling!

The 18mm BCO and in particular the 16T5 presented an almost delicate, highly contrasted view that reflectors do not. Pinpoint tiny stars, jet black background, yes the frac was doing its job very well.

Wait until it sees the best skies...

I wont mention the diag differences and some other things, Ive been yapping too long lol which is not uncommon if you know me

Gerry

 

Edited March 11, 2023 by jetstream

[JeremyS]

Sounds like great views. But with the TSA 120 performing like that, do you really want to get an FC 100? (Says the guy that got an FC 100 to complement his TSA 120 😊)

[jetstream]

1 minute ago, JeremyS said:

Sounds like great views. But with the TSA 120 performing like that, do you really want to get an FC 100? (Says the guy that got an FC 100 to complement his TSA 120 😊)

Well, maybe you can help me out with this.

My temps can fall substantially for a long time right when the moon/planets are great to view ie just after dusk. Eventhough the TSA120 is "acclimated" during these times it can lag the temp drop a bit.

I'm talking say from +5c down to -15c or 0C to -20c etc. Normally, later on in the evening the temp stabilizes.

Will the doublet Tak 100 keep up substantially better than the triplet during these temp drops?

Please say yes

[JeremyS]

9 minutes ago, jetstream said:

Well, maybe you can help me out with this.

My temps can fall substantially for a long time right when the moon/planets are great to view ie just after dusk. Eventhough the TSA120 is "acclimated" during these times it can lag the temp drop a bit.

I'm talking say from +5c down to -15c or 0C to -20c etc. Normally, later on in the evening the temp stabilizes.

Will the doublet Tak 100 keep up substantially better than the triplet during these temp drops?

Please say yes

Yes 😊

Though in my locale, we don’t often get such large rates of decline, so the TSA 120 is not so slow to acclimate. 

If you want something that is very fast to deploy AND gives stunning images, maybe the FOA 60Q is worth thinking about. Superb on doubles and brighter DSOs. But it won’t show you details in M51

[jetstream]

Just now, JeremyS said:

Yes 😊

Though in my locale, we don’t often get such large rates of decline, so the TSA 120 is not so slow to acclimate. 

If you want something that is very fast to deploy AND gives stunning images, maybe the FOA 60Q is worth thinking about. Superb on doubles and brighter DSOs. But it won’t show you details in M51

Whew!!!

Ive been looking for an excuse to buy one and the wife is finally on board with my latest reason😁

Coming in sad, bummed out because my scope wont keep up to the drop , only giving 225X lunar views 😔

Ive been rehearsing for a while

[Sunshine]

My 102 will cool a bit quicker than your 120, maybe we should trade? 😂  

Edited March 11, 2023 by Sunshine

[jetstream]

@JeremyS In all seriousness, I dont want to miss great seeing opportunities because of the acclimation issue or local seeing issues- Ive addressed the latter ie thermal slide, base etc.

I plan on the Tak 100 next to the 120 side by side and if things work out I slide over to the 15" which is always in the wings.

[jetstream]

2 minutes ago, Sunshine said:

My 102 will cool a bit quicker than your 120, maybe we should trade? 😂  

😁

I'll trade you a bit of cash for it but I'll probably be buried with my Taks (and fishing rod)

[Mr Spock]

It's surprising how capable 120mm scopes are. My old achro 120mm gave me the best views I've had of M42 - lovely extension to the 'wings'. Sadly my LP has gotten worse and even the 12" doesn't get there now 

[mikeDnight]

6 hours ago, jetstream said:

In my eager dream to test the new 2.5mm XO, I set the TSA120 up for lunar and initiated the final cooling process. Not wanting to waste this observing time I set out to see a couple of favourites, M51 and M42.

Avg (-) transparency had the NELM around 5.9, not the best, but OK.

M51 was low during the cooldown time but it was in between the trees and so observable. I'm not sure how many have played round with smallish scopes on this object but the views can be very good. In these scopes its best (to me) to play around with the mags and try a bunch of different eyepieces.

The 24ES 68 found M51 manually and presented a nice very distinct set of galaxies, however experience told me there was much more in there. In goes the excellent 18BCO and some intermittent "mottling" appeared in the outermost of M51, knowing what this meant the 16T5 Nagler came out.

If you ever observe M51 as round with no spirals, but with intermittent streaks in the outer portion of it, you are actually seeing the spirals. These streaks can be seen as faint small mottling or in my case last night as distinct, faintish intermittent streaks. Magnification brings these out and usually around a 2mm exit pupil in small scopes works well.

A very fine view!

M42! What can I say! The Tak bought out a highly green core with massive wings espc on the one side and M43 showed a nice but small comma shape. The extensive glow of the Running Man was in your face and the whole thing was dazzling!

The 18mm BCO and in particular the 16T5 presented an almost delicate, highly contrasted view that reflectors do not. Pinpoint tiny stars, jet black background, yes the frac was doing its job very well.

Wait until it sees the best skies...

I wont mention the diag differences and some other things, Ive been yapping too long lol which is not uncommon if you know me

Gerry

 

Thanks for sharing your experience with youre superlative 120. It sounds like you had terrific fun.   You started by mentioning your 2.5mm XO. Did you have fun with that too?

Edited March 11, 2023 by mikeDnight

[jetstream]

Just now, mikeDnight said:

You started by mentioning your 2.5mm XO. Did you have fun with yhat too?

I had a great observing session Mike!!

After the DSO adventures I came in the house and waited for the moon to rise watching "On Golden Pond"

And dozed off 😂

At 11:30 I went out and checked the moon and it was behind the tree tops with its current trajectory so I packed up and went to bed. I must be getting old... a few years ago I would have carried the AZEQ6 down to the lake to obs....

This is another reason (excuse) for the 100mm Tak- for a light portable set up.

[dweller25]

5 hours ago, jetstream said:

Well, maybe you can help me out with this.

My temps can fall substantially for a long time right when the moon/planets are great to view ie just after dusk. Eventhough the TSA120 is "acclimated" during these times it can lag the temp drop a bit.

I'm talking say from +5c down to -15c or 0C to -20c etc. Normally, later on in the evening the temp stabilizes.

Will the doublet Tak 100 keep up substantially better than the triplet during these temp drops?

Please say yes

Yes 🙂

But a 128mm Fluorite doublet does too but with better views 👍

Just saying 🤣

[jetstream]

Just now, dweller25 said:

Yes 🙂

But a 128mm Fluorite doublet does too but with better views 👍

Just saying 🤣

I was hoping you didnt say that 😁 The thought crossed my mind... and Ive seen some remarkable test results of the FS128... very remarkable.

Hey😈 you got one youll sell me?!

[mikeDnight]

Just a thought Gerry.  Could the lagging performance be due to atmospheric ice particles forming in the low temperatures, and washing out the definition?  

[jetstream]

28 minutes ago, mikeDnight said:

Just a thought Gerry.  Could the lagging performance be due to atmospheric ice particles forming in the low temperatures, and washing out the definition?  

Thats part of it for sure at times and combine this with my scope at say 0C and a steady, fairly quick drop in temps the view suffers. Last night I could see light high cloud "haze" around the moon (after waking up lol) and no doubt ice crystals were at play here too, it was cold -17c or so last night.

The views the TSA give are amazing and in reality I need another scope like a hole in the head

 

[dweller25]

13 hours ago, jetstream said:

Well, maybe you can help me out with this.

My temps can fall substantially for a long time right when the moon/planets are great to view ie just after dusk. Eventhough the TSA120 is "acclimated" during these times it can lag the temp drop a bit.

I'm talking say from +5c down to -15c or 0C to -20c etc. Normally, later on in the evening the temp stabilizes.

Will the doublet Tak 100 keep up substantially better than the triplet during these temp drops?

Please say yes

It just dawned ( or should that be dusked 🤣) on me that an actively cooled 6” F/8 Newtonian with premium optics could be a option for keeping up with rapidly dropping temperatures.

[jetstream]

4 hours ago, dweller25 said:

It just dawned ( or should that be dusked 🤣) on me that an actively cooled 6” F/8 Newtonian with premium optics could be a option for keeping up with rapidly dropping temperatures.

Ya but then I wouldnt have go worry about longitudinal chromatic aberration or spherochromatism or if I have fluorite and ultra high low dispersion glass or ,or

What would I do then?!! Id be bored silly 😐

[dweller25]

1 hour ago, jetstream said:

Ya but then I wouldnt have go worry about longitudinal chromatic aberration or spherochromatism or if I have fluorite and ultra high low dispersion glass or ,or

What would I do then?!! Id be bored silly 😐

Aaah, your a refractor guy 😱😂

Me too 👍

…..apart from the Mewlon 😆

Edited March 12, 2023 by dweller25

[jetstream]

3 hours ago, dweller25 said:

Aaah, your a refractor guy 😱😂

Me too 👍

…..apart from the Mewlon 😆

Me too

aside from the VX10, 15",24" 🙄

I'm looking at Mewlon CRS with active cooling... I wonder if there is a visual advantage to these regarding cooling etc?

[dweller25]

Yes I think so,

Apart from the quicker time to reach ambient temperature, active cooling will also remove the boundary layer that clings to the primary surface so views will look better earlier even when the primary is still trying to reach ambient, as you probably see in your Newts.

I saw this many times with my Intes 715. Before it had reached ambient views were compromised but when I turned the cooling fan on it sharpened up instantly. But eventually the corrector would dew up on the INSIDE so it was game over.

Mewlons do not have that problem and they are VERY comfortable to view with 🙂

Edited March 13, 2023 by dweller25