Altair Astro 72EDF arrived today

[John]

I'm not an imager but that looks very fine to me

[Yawning Angel]

10 minutes ago, StaceStar said:

First light

57x60s

I'd be very happy with that - enjoy your new toy!

[StaceStar]

7 minutes ago, Yawning Angel said:

I'd be very happy with that - enjoy your new toy!

 

9 minutes ago, John said:

I'm not an imager but that looks very fine to me

Thanks very much both. I'm not the best at processing.... Still learning but I'm quite happy. 

[Chris]

22 hours ago, John said:

If the scope has a strehl ratio of .990 and is figured to 1/13th wave peak to valley then it should show a practically perfect star test under decent seeing conditions.

The test report on paper at least looks a bit confusing to me. 0.990 Strehl is astoundingly good, but then why is the computer generated star really trainglular and pinched. In other words, how can a pinched looking star focus 99% of the light in exactly the same plane? 

I'm glad to see the real life results look good  

[StaceStar]

1 minute ago, Lockie said:

The test report on paper at least looks a bit confusing to me. 0.990 Strehl is astoundingly good, but then why is the computer generated star really trainglular and pinched. In other words, how can a pinched looking star focus 99% of the light in exactly the same plane? 

I'm glad to see the real life results look good  

[StaceStar]

Just now, StaceStar said:

That's an upclose of the simulated star. I spoke to Altair about this, it was a polishing artefact most likely. If you look at the wave height it's really a none issue. I work with lasers in my job a little, and after having it all explained to me it's all a bit clearer. Basically this lens is a bit of a fluke

[StaceStar]

We also discussed the strehl scores from the rest of the batch. All are very good. Just not as good as this one

[Chris]

22 hours ago, GavStar said:

John, what about this as a comparison?

 

This looks better, more inline with the high Strehl. The main thing is that you understand and are happy as it's your scope. You're clearly happy with it as you should be looking at the real life results. Looks very good, I hope you enjoy the scope   

[StaceStar]

1 minute ago, Lockie said:

This looks better, more inline with the high Strehl. If polishing artifact is the explanation of the pinched test star, and the real life star looks different to this, then I can't say I understand, it's a bit over my head. The main thing is that you understand and are happy as it's your scope. You're clearly happy with it as you should be looking at the real life results. Looks very good, enjoy   

I probably didn't explain the best either. Its not my forte ? but you are right. The stars look good. No crazy shapes 

[Chris]

1 minute ago, StaceStar said:

I probably didn't explain the best either. Its not my forte ? but you are right. The stars look good. No crazy shapes 

I once bought a fast 8" f/4 Newtonian, and the previous owner had glued the entire back of the primary mirror to the mirror support.....I swear the stars were figure of eight shaped "8"!

[StaceStar]

3 minutes ago, Lockie said:

I once bought a fast 8" f/4 Newtonian, and the previous owner had glued the entire back of the primary mirror to the mirror support.....I swear the stars were figure of eight shaped "8"!

Whaaaaaaaat ????

[Adam J]

57 minutes ago, StaceStar said:

First light

57x60s

AA72edf, AA lightwave 0.8 reducer, AA hypercam 183c pro, Skywatcher Heq5 pro

Looks good though you might want to tweak the spacing on your flattner slightly. Don't worry to much about the test report, lots of people buy scopes without any report at all and they don't dwell on it so long as the images look good.  

[StaceStar]

10 minutes ago, Adam J said:

Looks good though you might want to tweak the spacing on your flattner slightly. Don't worry to much about the test report, lots of people buy scopes without any report at all and they don't dwell on it so long as the images look good.  

Thank you. Will do

[GavStar]

34 minutes ago, Lockie said:

This looks better, more inline with the high Strehl. The main thing is that you understand and are happy as it's your scope. You're clearly happy with it as you should be looking at the real life results. Looks very good, I hope you enjoy the scope   

Lockie,

I should explain that this picture is from the test report from my Altair 72mm that I received yesterday. However my Strehl was not the crazy high 0.99 but still over nicely over 0.95.

First light tonight hopefully ?

[StaceStar]

5 minutes ago, GavStar said:

Lockie,

I should explain that this picture is from the test report from my Altair 72mm that I received yesterday. However my Strehl was not the crazy high 0.99 but still over nicely over 0.95.

First light tonight hopefully ?

Interesting, I've probably got a bit of your test report in my inbox (no way of identifying though) Altair sent me a few excerpts from the batch to compare 

[Chris]

2 minutes ago, GavStar said:

Locker,

I should explain that this picture is from the test report from my Altair 72mm that I received yesterday. However my Strehl was not the crazy high 0.99 but still over nicely over 0.95.

First light tonight hopefully ?

Hey Gav, I did wonder were the other test report came from; was it a replacement test report I thought due to the first one being wrong? I'm having one of those days where I'm confused by almost everything, so not a good day to questions things in hindsight :d  Good luck with first light, I did see your new additions on the show me your frac thread, very nice indeed.

[Louis D]

5 hours ago, Lockie said:

I once bought a fast 8" f/4 Newtonian, and the previous owner had glued the entire back of the primary mirror to the mirror support.....I swear the stars were figure of eight shaped "8"!

If he/she had simply glued it at three points (to determine a plane), it would have been fine.  Small, lightweight mirrors don't really need a complex mirror cell.

[StaceStar]

One airy disc, slightly off on the one side as my camera is slightly tilted. I've worked that out now. But yeah it looks pretty much exactly the same on the other side of focus.

[astrosathya]

18 hours ago, StaceStar said:

First light

57x60s

AA72edf, AA lightwave 0.8 reducer, AA hypercam 183c pro, Skywatcher Heq5 pro

You're Astrostace from some other forum on Facebook? just curious.

[StaceStar]

5 minutes ago, astrosathya said:

You're Astrostace from some other forum on Facebook? just curious.

That's me!

[John]

15 hours ago, StaceStar said:

One airy disc, slightly off on the one side as my camera is slightly tilted. I've worked that out now. But yeah it looks pretty much exactly the same on the other side of focus.

Need to get the camera level before interpreting anything. With that image the objective appears out of collimation (airy disk not central) and the diffraction rings are unevenly illuminated. But as you say the camera was tilted so that would explain that. 2nd diffraction ring seems quite bright too. I'm probably reading too much into this though - it's easy to get OCD about things !

Here is a set from a Celestron ED80:

 

 

[StaceStar]

35 minutes ago, John said:

Need to get the camera level before interpreting anything. With that image the objective appears out of collimation (airy disk not central) and the diffraction rings are unevenly illuminated. But as you say the camera was tilted so that would explain that. 2nd diffraction ring seems quite bright too. I'm probably reading too much into this though - it's easy to get OCD about things !

Here is a set from a Celestron ED80:

 

 

I think you might be. I'll do it again properly without the camera tilt ??. Others have said it looks great though so I'm very happy . 

[John]

2 minutes ago, StaceStar said:

  so I'm very happy . 

That is really the most important thing

Probably best to press on with using it for what you enjoy doing with it rather than messing around with star tests.

[StaceStar]

3 minutes ago, John said:

That is really the most important thing

Probably best to press on with using it for what you enjoy doing with it rather than messing around with star tests.

I guess I like to help people out that's all I'll probably get round to it at some point. Maybe in winter, when darkness isn't such a premium