dithering with 2 cameras on single mount

[lynnhilborn]

Anything new here ? This was an option Guylain was thinking of introducing a few years back. I am going to Chile with 2 6D's and a single mount and want to operate two instances of BYEOS and be able to dither the mount with 2 cameras operating?

If lt hasnt been implemented in the software is there a place one can purchase the proper Y cable to do it via hardware ?

Thank you

[admin]

7 minutes ago, lynnhilborn said:

Many, many thanks...brilliant, just what I needed.

Oops, the link I provided is old and the process has changed, for the better.

For the newer instructions... download 3.1.16 and install.

Then see the instructions on page 47 of the user guide.

Regards,

 

 

[skycamper]

On 2/5/2018 at 1:13 PM, admin said:

Oops, the link I provided is old and the process has changed, for the better.

For the newer instructions... download 3.1.16 and install.

Then see the instructions on page 47 of the user guide.

Regards,

 

 

Can the premium version of BYN do two cameras with dithering?  Im using two D5300 cameras. If not,  what's the work around with a Y splitter or tether ??

Thanks

Abraham

[admin]

2 minutes ago, skycamper said:

Can the premium version of BYN do two cameras with dithering?  Im using two D5300 cameras. If not,  what's the work around with a Y splitter or tether ??

Thanks

Abraham

No need for the y splitter cable.  The latest BYN 2.0.9 PREMIUM will do the same as BYE 3.1.16.

 

[lynnhilborn]

the 2 camera with dithering works just fine....remember that the Master camera will control all the settings on the slave camera so you will have identical settings in terms of exposure, f stop, iso etc. Even if you set the slave camera with different settings they will default to the Master.

[admin]

Oh Lynn... make sure to have a copy of your license/identifier with you on your PC when traveling... because if you change time zones you may need to re-validate your key.  This is because this is seen, sometimes, as a sign that the key was copied from another pc.  If you have it on hand and you don't have INTERNET where you have it may save your trip.

[admin]

3 minutes ago, lynnhilborn said:

the 2 camera with dithering works just fine....remember that the Master camera will control all the settings on the slave camera so you will have identical settings in terms of exposure, f stop, iso etc. Even if you set the slave camera with different settings they will default to the Master.

Correct.  This is be design.

[lynnhilborn]

Thanks Guylain....yes, I always keep a hardcopy of my license etc....good to know you have that safeguard. Thanks the wonderful software, it is really a work of art !

[skycamper]

2 hours ago, lynnhilborn said:

Thanks Guylain....yes, I always keep a hardcopy of my license etc....good to know you have that safeguard. Thanks the wonderful software, it is really a work of art !

This happened to me in a forest in the middle of Minnesota,   Luckily I had the Key!  

[skycamper]

I find that with my light pollution I cant image longer than 2 min. With BYN and sharpcap or pole master I find that I can image without guiding. One less thing which I was bad at anyway.    I have two SV105T's and two D5300's can they be dithered without guiding and would it still require Phd2 to dither without guiding?

Thanks

[admin]

37 minutes ago, skycamper said:

I find that with my light pollution I cant image longer than 2 min. With BYN and sharpcap or pole master I find that I can image without guiding. One less thing which I was bad at anyway.    I have two SV105T's and two D5300's can they be dithered without guiding and would it still require Phd2 to dither without guiding?

Thanks

With the premium you can, but the feedback I have received is that direct mount dithering is too aggressive.  In contrast, when guiding with MetaGuide, dithering is instant.

[astroman133]

Dithering without guiding (AKA ASCOM Guiding) does not need an external app like PHD2 or MetaGuide). It uses the Premium Edition's ASCOM telescope control to move the mount. If you have the 2 refractors mounted side-by-side on the same mount then you would use the master-slave relationship to keep the 2 cameras in sync.

If they are on separate mounts then you could theoretically control each mount independently. However, if the mounts use the same driver then it will not work unless the telescope driver author supports controlling multiple mount instances from the same computer. If the mounts use different drivers then it should not be a problem.

[skycamper]

If dithering without guiding is too aggressive with the ascom driver perhaps I can guide using phd or meta guide using very weak settings or disable guide output settings??    The reason being that I've never perfected guiding. Someday I will when I need to guide longer than a few minutes.

[astroman133]

But PHD and MetaGuide require an optical train with a guide camera. There are many setups to accomplish this. One is with a piggybacked guidescope and camera. Another is with the guide camera mounted off-axis. ASCOM guiding does not require any guide scope or camera.

If you disable the guide outputs, then you aren't actually guiding. If you aren't guiding then you may not need to dither since the field of view will shift due to polar mis-alignment.

My understanding is that dithering with a DSLR, or any camera with a Bayer array (color), needs to be more aggressive than with a monochrome camera. This is because as each pixel is de-Bayered, it gets contributions from neighboring pixels for its missing colors. If you want to use unguided dithering, then you should try it and see how much each move is shifting the image. I would say that a 4-8 pixel shift would not be too aggressive for a DSLR.

Another point is if you have a guide camera arrangement, why don't you learn how to use it? I have no experience with MetaGuide, but there are many resources available to help you learn how to use PHD. I have been using PHD for several years and am able to guide until the scope hits the meridian or the horizon. There is a bit of a learning curve, but with a decent mount and a good polar alignment you should be able to guide well and without issues.

[skycamper]

That's true and yes I usually use a 50mm guider , I guess I've worked myself pretty hard without perfecting the guiding on my C11XLT,  and in fact had better results unguided.   But I was also fighting my NEQ6 , focus sag, collimation,  a NEQ6 is probably not enough mount for a C11 imaging, but anyway yes I can guide and am hoping dropping to 700mm will be easy as pie.  One good reason to guide even short subs would be to keep the object from drifting away and then have to stop and put the object back in the center of the FOV despite a great PA.....  That's why I need to learn plate solving, it's hard over shooting an obect and then using the hand paddle to recenter when right is down and left is up......I've wasted hrs there....  Everything is harder at 2000 mm.

Once I need to guide longer than a few min I'll go in that direction.  How will I know if I'm dithing 8-10 pixels? 

[astroman133]

If you are using a 50mm finder to try to guide a 2800mm imaging scope, that could be part of your problem. You might find that your guiding would be improved if you used a guide scope that has a longer focal length, say around 400mm.

Switching your imaging scope to a shorter focal length refractor will make a world of difference. You may even be able to guide through the finder.

I believe that you can use the PHD History graph to how far you are dithering.

[s3igell]

4 hours ago, skycamper said:

That's true and yes I usually use a 50mm guider , I guess I've worked myself pretty hard without perfecting the guiding on my C11XLT,  and in fact had better results unguided.  

A 50mm Guider (usually 160mm Focal Length) is far too little Focal Length for a 2000mm Imaging Focal Length:  the Rule-of-Thumb is the Guiding Pixel Resolution needs to be at least 1:5 the Imaging Resolution.  You were attempting more like 1:20 Resolution-Ratio, and would need to mount an 80mm f/8 Guide Scope or else use OAG (which also has its challenges).

Quote

But I was also fighting my NEQ6 , focus sag, collimation,  a NEQ6 is probably not enough mount for a C11 imaging,

Mounting a C11 with all the gear (Camera, Guider, Losmandy Dovetail) will weigh near the top-end of what a well-maintained NEQ6 can readily handle, but you likely were fighting other Issues than Weight.  Unless your C11 is actually an EdgeHD11, you lack the Mirror Locks which would address Focus Sag and Collimation concerns.  That is going to be your biggest nemesis for successful Guiding of your C11.  The solution is to move to an OAG Guiding Rig (Off-Axis Guider - prism-based Pick-off rig which mounts the Guide Camera perpendicular to the Optics train behind the Focuser, where it performs Guiding at a point AFTER Focuser/Mirror Sag and Collimation occur).

Quote

One good reason to guide even short subs would be to keep the object from drifting away and then have to stop and put the object back in the center of the FOV despite a great PA.....

Sorry, but if you experience noticeable Drift, then your PA is at best "nominal".  PoleMaster is only spec'd to get one "an accuracy of up to 30 arc seconds" (per qhyccd.com) - an accuracy that you can easily exceed by either All-Star Polar Align or Drift Align routines.  (And 30 arcsec accuracy is exacerbated by the long 2000mm Focal Length.  Unfortunately, Focal Length has it's drawbacks...)

Quote

Everything is harder at 2000 mm.

You are correct...  Long Focal Length AND Slow Focal Ratio (f/-ratio) add up to making a C11 a Challenge.  You mention "dropping to 700mm" - which will totally change your Experience...

But, whichever Scope (and combo of gear), keep at it...  AP Imaging is Doable and Rewarding.

 

[skycamper]

Thanks guys this does make sense.  I have the necessary OAG and longer guide scope, will have to try with those.  I love my carbon fiber C11XLT and I use a starizona .63x reducer and I see others with excellent results , I need to keep playing with it.  Meanwhile I have a C11HD and a hyperstar system also waiting for my skills to catch up, I would like to own a mach 1 some day.  I should take a break and go back to my SV refractors. Yes 730mm. 

[admin]

It's been implemented at least 2 years ago.  This is a premium feature.  You need 2 instances of BYE running, one master and one slave.  See dual camera support in the user guide.

Regards,

[lynnhilborn]

I dont see dual camera support in the User Guide...I have Premium edition 3.1.4

regards

[admin]

Upgrade to 3.1.16.

Then read this post, it's pretty straight forward to use 2 cameras.

 

[lynnhilborn]

Many, many thanks...brilliant, just what I needed.