Tip-tilt adaptive optics needed

capeorion

Your excellent cameras would benefit from a tip-tilt adaptive optics system. There are essentially few AO systems available to the amateur astronomer that are affordable. A well executed system utilizing ZWO cameras are a natural next step for your product line and will greatly expand the company’s market share. Please give this idea serious consideration.

riklaunim

For DS imaging or do you want one for Solar System imaging?

I'm afraid that patents and general knowledge of companies doing AO maybe something that will make it really hard for others to overcome. Orion had some AO but right now it looks like they dropped those products, while SBIG or SX systems start at 1000-1500 EUR.

capeorion

riklaunim wrote:
For DS imaging or do you want one for Solar System imaging?

Actually both DS and Solar system would benefit as the system reduces the effects of atomspheric seeing. It could turn a seeing night of 3 , which is just good to a seeing night of 5 , which is excellent.

I'm afraid that patents and general knowledge of companies doing AO maybe something that will make it really hard for others to overcome. Orion had some AO but right now it looks like they dropped those products, while SBIG or SX systems start at 1000-1500 EUR.

I am not aware of any intellectual property barriers regarding AO as most of the early research and development was funded by the US government and conducted at public universities. Regardless, it makes no sense to reinvent the wheel. The shortest path to success would be to work with SBIG ( diffraction limited.com) and develop an adapter that would retrofit their existing product offerings to work with the ZWO cameras. That way everyone wins.

benni

I have an AO and have written here about the effects that I see

https://bbs.astronomy-imaging-camera.com/viewtopic.php?f=27&t=7167#p17245

ZWO sensors allow short exposures that render mount errors are not observable.

On the other hand the current ao setups for the amateur are not fast enough to remove seiing effects.

My ao from starlight xpress only corrects at around 2.5 hz, which is not fast enough for seeing.

Sbig claims it can correct 10 hz http://diffractionlimited.com/product/ao-8a/

That may be enough to correct seeing.

But I wonder: I have the lodestar guider which is known to be very sensitive... And I rarely find a guide star where I can do exposures below 0,5 s. Sometimes there are guidestars with 0,1 s. but for 10 hz correction, with all that latency stuff from Software and Laptop and cables, I think you need a software and and a guiding cam and a hardware connection that simply does not exist yet....

Or does sbig have a much faster and much more sensitive guider cam than all the other competitors around?

Support@ZWO

Hi there

Thank you very much for telling us your willings. AO system is very cool staff, we will consider it in the further.

benni

As to the claims from sbig with 10 hz....

http://diffractionlimited.com/product/ao-x/

Well, they say:

For STX cameras, the AO-X stacks on top of the FW7-STX and STX Guider

And what does the STX guider specification say:

http://diffractionlimited.com/product/stx-guider/

Full Frame Download: 0.13 sec

Additionally, their guider is an old KAI-0340 ccd chip from Kodak.... Quantum efficiency is claimed to be 55.... That's lower than my old lodestar which has 65 or so...

With that you are basically guaranteed to need exposures longer than 1s... Maybe some rare times you will get a guidestar with 0,5s exposure time...

and to that come 0,13 sec download time, and then maybe 0,1sec computing time and sending the correction... That is 0,73 sec...

And there goes sbig's nonsensical 10hz claim....

If one wanted to do this, then one probably would need to have usb-c and a camera firmware that can download only a small section of the image if needed. Or perhaps even to do the entire guiding in the ao. That is, the laptop is only used to set the parameters, manually select the guidestar, observing whether guiding works, but everything else (the real guiding process) works internaly in the ao...

This may remove the frame download and windows/linux guiding software bottleneck...

If the guiding chip is then a sensitive cmos, then one probably could really talk about more than 5hz if the ao can move the glass really fast....

Support@ZWO

We will do some research on it. It's a really good staff.

benni

I have re read the manual from my sx ao. It says

"the ao is capable to make corrections in a few milliseconds but in reality it deoends on the guiding camera".. Some vendors even claim 5ms...

I think I will now try to use subframes and st4 cables instead of pulesguiding via ascom and see whether this helps... But yeah I think it seems laptop, usb, and camera and software is making it slow, not the ao itself...

Support@ZWO

Yap. we will figure it out in the further.

benni

for the record here is the ao from starlight xpress that I have

https://www.sxccd.com/sxv-ao-lf

one can also buy it without the sx off axis guider if one already has one

https://optcorp.com/products/starlight-xpress-active-optics-with-usb

If somebody wants such a system to use it with a zwo camera then the starlight xpress ao should work without problems. It just adds 36mm to the backfocus.

When computing the correct distance, one must bear in mind that it has a 13mm thick glass. That means one must subtract 13/3mm from the mechanical length in order to compute the correct distance between a reducer or flattener... Filters and the protective glass of the zwo camera usually add 2mm glass for each where one has to subtract 1/3 of the thickness each. So of one has a filter wheel and this ao and a zwo camera, then one has to subtract 5.6mm from the mechanical distance of the ao....

Support@ZWO

Thank you very much.

benni

Phd guiding supports the sx ao. one can connect to it like a mount...

If somebody knows how to increase the frequency of the setup (with a special guiding camera or a laptop, a configuration tweak in the drivers or software, or a software other than phd guiding) please let me know...

Support@ZWO

Maybe ask this on Cloudy Night? there will be more people might use AO.

benni

Good Idea, will definitely try to ask there...

But if zwo constructs a fast off axis guiding system with adaptive optics that can correct seeing sufficiently and does not add too much backfocus,

then you would be way ahead of any of your competitors....

These megapixel sensors often have large resolutions that should not get lost just because of seeing...

Benjamin

benni

I have now bought an ASI 290 mini camera and used it with the starlight Xpress active optics.

With the lodestar, using subframes in phd guiding, I only got 5-10 hz.

When I use subframes with the asi 290 mini I get 10-20 hz. (But I connect the asi with 2 cables and the ao sits on the usb port of the asi 1600... so perhaps with fewer cables and a direct connection to the ao, it would get even faster)...

An usb 3 or usb c camera mini guiding camera would probably be even better for the frequency... Unfortunately, the large USB 3 cameras from zwo do not really fit to my setup because of their form factor...

Getting to 10 hz and faster bring some improvements, I think... But the star still jumps... 50-100 hz would be considerably better. But then it is of course the problem that seeing is uncorrelated between different regions of the image. I guess one would need an on axis guider to correct that..

I will now try to guide soon without ao, with ao and at different exposure times to see whether I really get smaller stars at higher frequencies..

This way one can see whether these ao things are just a playtool or whether they are really interesting... At least they yield a perfect mount....

Support@ZWO

Benni wrote:
I have now bought an ASI 290 mini camera and used it with the starlight Xpress active optics.

With the lodestar, using subframes in phd guiding, I only got 5-10 hz.

When I use subframes with the asi 290 mini I get 10-20 hz. (But I connect the asi with 2 cables and the ao sits on the usb port of the asi 1600... so perhaps with fewer cables and a direct connection to the ao, it would get even faster)...

An usb 3 or usb c camera mini guiding camera would probably be even better for the frequency... Unfortunately, the large USB 3 cameras from zwo do not really fit to my setup because of their form factor...

Getting to 10 hz and faster bring some improvements, I think... But the star still jumps... 50-100 hz would be considerably better. But then it is of course the problem that seeing is uncorrelated between different regions of the image. I guess one would need an on axis guider to correct that..

I will now try to guide soon without ao, with ao and at different exposure times to see whether I really get smaller stars at higher frequencies..

This way one can see whether these ao things are just a playtool or whether they are really interesting... At least they yield a perfect mount....

Thanks for share!

benni

I think i have a product idea...

Maybe you can put two chips in your cameras. The main chip and next to it a guiding chip.

The guiding chip can act as a normal guiding camera.

This makes off axis guiders and guiding scopes unnecessary. So the user can save some money and weight and without off axis guider one needs not that much backfocus...

Now some cameras have an anti shake mechanism not in the lens but on the sensor. This technique is also used in the pan starrs telescopes to reduce seeing. Piezo crystals can move fast enough.

Seiing has a frequency of 100hz. A typical 2.85" square, .0075" thick sheet of PSI-5A material has a thickness mode vibration in the neighborhood of 13 MHz and a planar dilatation mode at around 14 KHz.

This is much faster than an optical stabilizer.

So if the mainboard of future asi cameras sits on piezo cystals and corrects its position via an integrated auto guiding chip, we can really get to the optical limit of our instruments....

Support@ZWO

put two chip on one board, there is one problem, if use narrowband filter, the guider maybe can't see any stars.

benni

hm some of your competitors have cameras with an integrated filter wheel. perhaps one could construct such a thing in a way that only the main chip gets light through the filter... imagine a filter wheel with a filter and a rectangular hole for the guiding chip with very little backfocus just in front of the chips.... and the chips can move veritcally and horizontally with piezo elements and sit on a cooled peltier element.. that way the system can guide, use filters without obstructing the guiding chip and have no vignetting....

perhaps a t2 connection would not suffice for that but m48 would perhaps have enouh diameter when a micro four thirds main chip is used along a small guidingnchip and an 1,25 filter wheel with a separate hole for the guiding is placed almost directly above the chips...

Support@ZWO

Benni wrote:

hm some of your competitors have cameras with an integrated filter wheel. perhaps one could construct such a thing in a way that only the main chip gets light through the filter... imagine a filter wheel with a filter and a rectangular hole for the guiding chip with very little backfocus just in front of the chips.... and the chips can move veritcally and horizontally with piezo elements and sit on a cooled peltier element.. that way the system can guide, use filters without obstructing the guiding chip and have no vignetting....

perhaps a t2 connection would not suffice for that but m48 would perhaps have enouh diameter when a micro four thirds main chip is used along a small guidingnchip and an 1,25 filter wheel with a separate hole for the guiding is placed almost directly above the chips...

We know competitors have all in one camera, we will consider about it, thank you.