Astrobiscuit is looking for quality astrophotographers to join the Big Amateur Telescope (BAT)

[rorymultistorey]

Hey folks, 

If you can shoot deep space targets well then I'd love you to join the BAT. Our goal is to gather amateurs from all over the world and for us all to shoot the same target, share our data and produce images that will rival big professional scopes. We are training folks up to shoot high resolution deep space images using the LUCKY IMAGING technique. The resolution we are able to achieve is really exciting but for the BAT to work we need lots of data and for that we need more good quality astrophotographers to join. The BAT members are working together on my discord server which is excellent for sharing ideas and working through problems together. If you want to join up here is the invite: https://discord.gg/WK8qmrqcpq
 

This is the video which really set the whole thing off and explains how us lowly amateurs are able to achieve resolution similar to that of multi million dollar telescopes

 

[Tiny Clanger]

I do hope you & Riktenstein will be coming up with a BAT theme song ... perhaps something along the lines of:

'Like a BAT imaging the heavens, I'll be gone when morning comes ... '

Seriously, love the vids, and even tho' astro photog.  is not my thing, I'll enjoy watching the outcome of the project

Heather

[rorymultistorey]

Obviously the most important thing is the theme song and the logo...

[saac]

Best video yet Rory and the others were already brilliant.   I'm always blown away with what you are achieving from London and in pushing your kit  - inspirational for sure.  And yes, we need a song  

Jim 

[DaveS]

This looks to be a job for CMOS rather than CCD. Not sure I have anything that fits the bill, though the TS apo with my QHY266M might do, but at barely 0.85"/px.

Possibly my old Trius 694 on the ODK would be interesting, giving sampling at near the Rayleigh limit, but a stupidly small FoV. A QHY 368 would be a similar resolution but at £nearly £4k a bit too much.

[Rob]

Great work once again. I've watched a few times now... great fun

Regards

Rob

[vineyard]

That's another fun video @rorymultistorey.  I'm actually learning mirror- & telescope- making from Terry - he's brilliant & the rest of the society are a good bunch as well. Nice to see them in the footage - no meetings have been possible for a while b/c of the pandemic ☹️ so a partially made mirror sits in a box on a shelf, biding its time.  How could you butcher the red tube like that you philistine 😂.  Will check out the discord server👏🏾

[vlaiv]

3 hours ago, rorymultistorey said:

We are training folks up to shoot high resolution deep space images using the LUCKY IMAGING technique.

What is the resolution you are aiming for?

[badhex]

6 hours ago, vineyard said:

That's another fun video @rorymultistorey.  I'm actually learning mirror- & telescope- making from Terry - he's brilliant & the rest of the society are a good bunch as well. Nice to see them in the footage - no meetings have been possible for a while b/c of the pandemic ☹️ so a partially made mirror sits in a box on a shelf, biding its time.  How could you butcher the red tube like that you philistine 😂.  Will check out the discord server👏🏾

I am also an alumnus of Terry's class. I moved to Germany a while ago so my part-finished mirror also sits in a box in storage! It was great to see the old gang on @rorymultistorey's video. 

Edited June 29, 2021 by badhex

[tomato]

Great video, your results with the lucky imaging show real promise, but getting our atmosphere to behave itself even for just 5 seconds at a time is asking a lot.

I have a similar fledgling project underway with @Tomatobro entitled the SNSLA (the Shropshire Not So Large Array), but I’d be happy to contribute to the BAT if my kit is compatible. My Esprit 150/ASI 178 combo can image down to 0.47 arcsec per pixel, but small targets only.

[rorymultistorey]

8 hours ago, DaveS said:

This looks to be a job for CMOS rather than CCD. Not sure I have anything that fits the bill, though the TS apo with my QHY266M might do, but at barely 0.85"/px.

Possibly my old Trius 694 on the ODK would be interesting, giving sampling at near the Rayleigh limit, but a stupidly small FoV. A QHY 368 would be a similar resolution but at £nearly £4k a bit too much.

You sir know what your talking about. I would really love you to join. BTW do you mean 268 not 266. I am very keen to get more folks in who know their onions. 0.853"/px is fine.

[rorymultistorey]

6 hours ago, vlaiv said:

What is the resolution you are aiming for?

So we are splitting our imagers into two camps. The regulars are aiming to get the FWHM of their stars to less than 5arcseconds wide and the elite lucky imagers are currently aiming to go less than 2.5arcseconds wide. Obviously we will start to push for more resolution soon. We haven't actually started lucky imaging yet what with it not getting dark and all but its clear a lot of folks need help with collimation etc before they can even start thinking about lucky imaging. We currently only have a handful of ELITEs who are nearly ready to push their kit to attain higher resolutions and I am very keen to find more. It would take me too long to explain everything here, suffice to say that their is a mountain to climb but we can see a path to the top.  I'm very lucky to have a good team helping. Now we need to get in more imagers who know what they are doing.

 

[DaveS]

Ha, urk yes, QHY 268, my rubbish typing.

[rorymultistorey]

1 hour ago, badhex said:

I am also an alumnus of Terry's class. I moved to Germany a while ago so my part-finished mirror also sits in a box in storage! It was great to see the old gang on @rorymultistorey's video. 

Everyone loves the Terry scene (except me!) Terry hasn't watched the video yet bc he doesn't have speakers on his computer. Bless!

[badhex]

Just now, rorymultistorey said:

Everyone loves the Terry scene (except me!) Terry hasn't watched the video yet bc he doesn't have speakers on his computer. Bless!

Classic Terry 😂 The Foucault tester looks exactly the same as it did seven or eight years ago and AFAIK he's had it for most of the life of the class. What a legend. Emailed a few of them after I saw the video, was nice to see everyone again - it actually made me quite homesick! 

[rorymultistorey]

1 hour ago, tomato said:

Great video, your results with the lucky imaging show real promise, but getting our atmosphere to behave itself even for just 5 seconds at a time is asking a lot.

I have a similar fledgling project underway with @Tomatobro entitled the SNSLA (the Shropshire Not So Large Array), but I’d be happy to contribute to the BAT if my kit is compatible. My Esprit 150/ASI 178 combo can image down to 0.47 arcsec per pixel, but small targets only.

Your Kit is amazing. I'd absolutely love to get you involved.  I can make a special channel just for the Shropshire Not SO Large Array that only you and your buddies can see and edit etc...  And of course you'll be able to access all the other channels that we're putting together to help build the BAT too. Together we're stronger. I think the platform we're setting up has the foundations to grow. I have a great team all working for free on   this project - one guy images at the Keck observatory - but to succeed we need to tempt the very best astrophotgraphers... not necessarily the biggest scopes  but folks who really understand how we can make this project  fly.

[rorymultistorey]

19 minutes ago, DaveS said:

Ha, urk yes, QHY 268, my rubbish typing.

thats actually the camera I want to lucky image with but don't currently have the funds to buy!

[rorymultistorey]

15 minutes ago, badhex said:

Classic Terry 😂 The Foucault tester looks exactly the same as it did seven or eight years ago and AFAIK he's had it for most of the life of the class. What a legend. Emailed a few of them after I saw the video, was nice to see everyone again - it actually made me quite homesick! 

Please can you thank them from me. Terry didn't want to give me their emails which is fair enough.

[vlaiv]

1 hour ago, rorymultistorey said:

The regulars are aiming to get the FWHM of their stars to less than 5arcseconds wide and the elite lucky imagers are currently aiming to go less than 2.5arcseconds wide.

So between about 3"/px and 1.5"/px as far as sampling rate goes?

That should be easily attainable with 6" scope, good mount and decent seeing without lucky imaging.

[rorymultistorey]

51 minutes ago, vlaiv said:

So between about 3"/px and 1.5"/px as far as sampling rate goes?

That should be easily attainable with 6" scope, good mount and decent seeing without lucky imaging.

Yes it should be obtainable... easily. And yet few manage it. There is no point in even trying lucky imaging until you reach this level of sharpness with  your set up. Also I just work in FWHM of stars in arcseconds I don't really know what you mean by - 3"/px and 1.5"/px as far as sampling rate goes - . I think about 0.5arcseconds per pixel is probably quite good but like I said I suspect I'm not understanding what you mean.

 

[vlaiv]

44 minutes ago, rorymultistorey said:

Yes it should be obtainable... easily. And yet few manage it. There is no point in even trying lucky imaging until you reach this level of sharpness with  your set up. Also I just work in FWHM of stars in arcseconds I don't really know what you mean by - 3"/px and 1.5"/px as far as sampling rate goes - . I think about 0.5arcseconds per pixel is probably quite good but like I said I suspect I'm not understanding what you mean.

 

Indeed - few people manage it, but I suspect it is down to few things:

1. Optics.

For that kind of resolution - namely 2.5" FWHM, you need good optics with enough of aperture. Using 80mm ED doublet and expecting 2.5" FWHM stars in OSC image is not really reasonable thing to do. Similarly using 6" Newtonian that is not properly collimated or CC spacing is not perfectly dialed in (or using CC that produces spherical aberration) is not going to do it.

2. Mount / guiding

Most people don't have enough guide resolution to precisely measure their total RMS because they are using small 50mm class guide scopes. These are fine for about 1-1.5" RMS guiding, but you need sub 1" RMS for 2.5" FWHM stars. Mount must be able to do it and guide resolution must be able to measure it properly.

3. Seeing of course. It is only doable on a night of good seeing - like <1.5" FWHM seeing (two second exposure).

Here is sort of a guideline:

150mm with 0.8" total RMS and 1.5" FWHM seeing will produce 2.5" FWHM stars if optics is diffraction limited

As for sampling rate - well, you can choose any sampling rate you want, but if you aim for say 2.5" FWHM stars - then you don't need to sample below 1.5"/px as you'll be over sampled. Many people sample at higher resolutions than that - and that wastes SNR.

There is simple relationship between the two (this is actually approximate relationship as we approximate PSF with Gaussian of certain FWHM) - sampling_rate = star_FWHM / 1.6

When someone is using say 0.86"/px - well if their stars are not 1.376" FWHM - then they are over sampling.

[rorymultistorey]

9 hours ago, vlaiv said:

Indeed - few people manage it, but I suspect it is down to few things:

1. Optics.

For that kind of resolution - namely 2.5" FWHM, you need good optics with enough of aperture. Using 80mm ED doublet and expecting 2.5" FWHM stars in OSC image is not really reasonable thing to do. Similarly using 6" Newtonian that is not properly collimated or CC spacing is not perfectly dialed in (or using CC that produces spherical aberration) is not going to do it.

2. Mount / guiding

Most people don't have enough guide resolution to precisely measure their total RMS because they are using small 50mm class guide scopes. These are fine for about 1-1.5" RMS guiding, but you need sub 1" RMS for 2.5" FWHM stars. Mount must be able to do it and guide resolution must be able to measure it properly.

3. Seeing of course. It is only doable on a night of good seeing - like <1.5" FWHM seeing (two second exposure).

Here is sort of a guideline:

150mm with 0.8" total RMS and 1.5" FWHM seeing will produce 2.5" FWHM stars if optics is diffraction limited

As for sampling rate - well, you can choose any sampling rate you want, but if you aim for say 2.5" FWHM stars - then you don't need to sample below 1.5"/px as you'll be over sampled. Many people sample at higher resolutions than that - and that wastes SNR.

There is simple relationship between the two (this is actually approximate relationship as we approximate PSF with Gaussian of certain FWHM) - sampling_rate = star_FWHM / 1.6

When someone is using say 0.86"/px - well if their stars are not 1.376" FWHM - then they are over sampling.

thx dude. You know this ain't my first time around the block.  I disagree with the old school view of sample rate. Take planetary imagers for example. That's all I'm going to say on the matter. Respectfully  you go your way and I'll go mine.

[vlaiv]

1 hour ago, rorymultistorey said:

thx dude. You know this ain't my first time around the block.  I disagree with the old school view of sample rate. Take planetary imagers for example. That's all I'm going to say on the matter. Respectfully  you go your way and I'll go mine.

Trying to be helpful and meant no offense, but sure, no need to discuss that further if you don't feel like it.

[rorymultistorey]

1 minute ago, vlaiv said:

Trying to be helpful and meant no offense, but sure, no need to discuss that further if you don't feel like it.

Its time that's my problem I don't have time and now I feel bad. I probably deserve to feel bad. Apologies

 

[vlaiv]

3 minutes ago, rorymultistorey said:

Its time that's my problem I don't have time and now I feel bad. I probably deserve to feel bad. Apologies

 

Please don't feel bad. Everything is fine. I'm looking forward to seeing the results of this collaboration.