E & F, easy innit?

[Stu]

Never quite sure where to put the apostrophe in ‘innit’ 🤣🤣

Anyway, having made the scope truck for my 16”, I decided to wheel it out tonight for a quick play while Mrs Stu was on a call.

Collimation took a while to sort out and the secondary is still not right, but the stars looked ok with it as it is, so I just got on with it.

Main reason for the report was, unsurprisingly given the title of the post, M42. I looked at it with the 31mm Nagler first, mainly as a finder. Views as you would imagine, but only really the main four stars on view in the Trap, perhaps hints of E. in went a 17mm Nagler and E became obvious, with hints of F.

Finally, the Docter 12.5mm. BAM, both E & F clear as day, just right there without trying. I guess the additional resolution and brightness just makes them that much easier. This scope has a huge secondary (4”!) so I don’t expect much from it at high powers necessarily and I’m sure it compromises the contrast but tonight it exceeded my expectations and gave a really great view of the Trap.

Refractor stars still trounce it, but I’ll take this gratefully.

EDIT I do wonder how much of not seeing these is just down to less sensitive eyes not picking up the faint stars, so the extra aperture just makes them that much easier for old geysers.

[JeremyS]

Great result @Stu. I wonder what colour(s) so saw in the nebula.

Don’t worry about an apostrophe in innit. There is none. Yet it is a question, so there should be a question mark at the end of the title. 😊

[Stu]

12 minutes ago, JeremyS said:

Great result @Stu. I wonder what colour(s) so saw in the nebula.

Don’t worry about an apostrophe in innit. There is none. Yet it is a question, so there should be a question mark at the end of the title. 😊

Better?

Not much colour, just hints of green really. I wasn’t dark adapted but not sure if that is a benefit for colour perception or not?

[John]

Nice report @Stu 🙂

E & F Trapezium were pretty straightforward with my 12 inch dob under any sort of decent seeing. The Ethos 8mm (198x) seemed to be a "goldilocks" eyepiece for that task with that scope.

These two fainter members of the Theta 1 Orionis group present a number of visual challenges I think, not least because they are set against a nebulous background. F of course has the added difficulty caused by the proximity of the brightest star of the "big four" in the group, C.

Onwards to G & H now then ? 😁

 

 

 

Edited February 11 by John

[Nik271]

4 inch secondary, as big as my refractor for tonight!

I was also looking at the trapezium at about 8pm and got a hint of E at x185. I find F quite hard even in my largest scope a 7 inch mak.

[Stu]

15 minutes ago, Nik271 said:

4 inch secondary, as big as my refractor for tonight!

I was also looking at the trapezium at about 8pm and got a hint of E at x185. I find F quite hard even in my largest scope a 7 inch mak.

I know, it’s a bit crazy. Need to sort a smaller one at some point.

[mikeDnight]

 

10 hours ago, Stu said:

Never quite sure where to put the apostrophe in ‘innit’ 🤣🤣

Anyway, having made the scope trick for my 16”, I decided to wheel it out tonight for a quick play while Mrs Stu was on a call.

Collimation took a while to sort out and the secondary is still not right, but the stars looked ok with it as it is, so I just got on with it.

Main reason for the report was, unsurprisingly given the title of the post, M42. I looked at it with the 31mm Nagler first, mainly as a finder. Views as you would imagine, but only really the main four stars on view in the Trap, perhaps hints of E. in went a 17mm Nagler and E became obvious, with hints of F.

Finally, the Docter 12.5mm. BAM, both E & F clear as day, just right there without trying. I guess the additional resolution and brightness just makes them that much easier. This scope has a huge secondary (4”!) so I don’t expect much from it at high powers necessarily and I’m sure it compromises the contrast but tonight it exceeded my expectations and gave a really great view of the Trap.

Refractor stars still trounce it, but I’ll take this gratefully.

EDIT I do wonder how much of not seeing these is just down to less sensitive eyes not picking up the faint stars, so the extra aperture just makes them that much easier for old geysers.

I think it should be i'n'n'it, just to be safe!

I took my DZ out tonight, and the E star was immediately obvious. The F star not so tonight  but the seeing was truly terrible. 

 

Edited February 12 by mikeDnight

[Stu]

4 minutes ago, mikeDnight said:

I think it should be i'n'n'it, just to be safe!

That’s what I thought too!! 🤣🤣

[Captain Scarlet]

Clear and dry night for me too for a change, and I’ve been vacillating whether or not to take out an easy scope (105) - your post has persuaded me to do it and give it an hour or so.

4” secondary is big but so is your primary: according to Suiter a 25% CO is still just about where you wouldn’t notice a difference contrast-wise from 16” unobstructed. So assuming the mirror is good and collimated, high powers and contrast should be no problem. Slightly jealous actually.

M

[Stu]

9 hours ago, John said:

Nice report @Stu 🙂

E & F Trapezium were pretty straightforward with my 12 inch dob under any sort of decent seeing. The Ethos 8mm (198x) seemed to be a "goldilocks" eyepiece for that task with that scope.

These two fainter members of the Theta 1 Orionis group present a number of visual challenges I think, not least because they are set against a nebulous background. F of course has the added difficulty caused by the proximity of the brightest star of the "big four" in the group, C.

Onwards to G & H now then ? 😁

 

 

 

Yes, it’s been a while since I used a larger scope, 8” is my normal max, and when I had a 12” I was back near London with poorer seeing and transparency. I was genuinely surprised to see them so easily. I’m sure G and H are beyond me, my skies and my eyes though!

[badhex]

Nice report @Stu!

The smallest (in fact only) scope I've managed both Trap E and F with is my 102ED, aroumd this time in 2022 - as I recall it was not that easy! 

[Mr Spock]

I've not looked at them recently. I'll have to give both scopes a go. I remember they were very easy in the C9.25 with the 22mm LVW.

[F15Rules]

Great stuff, Stu! (Innit!!😜🤭😄)..

I got out last night with Superfox, my new Vixen SD115S.

In between quite a few clouds passing over, I was able to see both E & F stars after about 20 minutes, with direct vision - with my "good" left eye..with my "poor" right eye, no chance of either! Same with binoviewers, I havent so far seen E or F with BVs, even in my old FS128.

Seeing last night was poor, but transparency between the clouds was good, and I find that for seeing E and F transparency is more important than seeing.

This evening I got out again, but this time both seeing and transparency were poor, and I couldn't see either E or F. I did manage to split Rigel and Alnitak, but not pretty images, and Sirius was a colourful dancing mess!!

And now the rest of this week looks end to end cloudy!🤦‍♂️😩..Innit?!!😁

Dave

[Flame Nebula]

On 12/02/2024 at 11:43, Mr Spock said:

I've not looked at them recently. I'll have to give both scopes a go. I remember they were very easy in the C9.25 with the 22mm LVW.

That's good to know, as I'm thinking of getting a C9.25 later this year, all being well. I have been oscillating between that scope, the C11 or a 10" dobsonian, but I'm particularly interested in planets, including AP, and splitting doubles. So, everything I've read suggests the C9.25 is best compromise. 

[bosun21]

The last time I seen the E & F stars was with a 150mm Mak. They are much easier to see with my 10" dob though. The 12" I used to own was the same although sky conditions and LP can be detrimental to large aperture scopes.

[bosun21]

On 11/02/2024 at 21:41, Stu said:

Collimation took a while to sort out and the secondary is still not right, but the stars looked ok with it as it is, so I just got on with it.

Do you have a Concenter Stu? I could borrow you my 2" one as they make collimating the secondary easy and accurate.

[Stu]

12 minutes ago, bosun21 said:

Do you have a Concenter Stu? I could borrow you my 2" one as they make collimating the secondary easy and accurate.

I do actually, thanks for the offer though.  I did give it a quick go the other night but think slightly more extensive adjustments are needed on the secondary to get it right. The support is three vanes and not quite as easy to adjust as a four vane spider.