Date   

Re: Problems using ASI air pro and AP mounts

stephanie@...
 

My understanding is that the MinMo parameter is hard coded to be 0.25 pixels on the AAP. If you are using a guide scope instead of an off-axis guider, you might have an +/- 1 arcsec (or more) of hysteresis, which will lead to some pretty bad zigzags.

Stephanie


Re: Will the Mach 2 support .....

Joseph Beyer
 

Thanks for posting John. Very nice image.  Even taken in a fairly light polluted environment it came out well.  Images like this make the decision to move away from a OSC camera more difficult.  Glad to see you’re able to image unguided with your Mach1/130.  

Joe

On Jun 3, 2021, at 3:43 PM, John Jennings <johnrogerjennings@...> wrote:


The following is my post to our clubs Facebook page. (Texas Astronomical Society of Dallas) An example of fairly fast image acquisition with a OSC CMOS camera. I'm trying to get efficient with my time as I'm getting older. 
 
IC443  the Jellyfish Nebula 
1/15/2021 - Nebula stack -  LeXtreme Pro
1/18/2021 - Stars stack - IDAS P3
From my backyard in Allen, Texas:
MPSAS 17.8-18.2 / Bortle 8-8.2 (Measured with SQM meter)
 
Finally got the results of my science project I've been working on for the last 3 months. Did not spend more than 2 hours on the work flow today... not including stack time. This is not an attempt at narrowband with shrunk or no stars, but rather a composite RGB image from a OSC camera with colorful background stars. Did spend a month or so on refreshing my math for sky background vs sub length calculations and doing a boatload of testing with filters and my SQM meter.  
 
63 subs @ 240secs (4.2hrs)  LeXtreme Pro
156 subs @ 30 secs (1.3hrs) Hutech LSP P3
Total integration for my Bortle 8+ sky was 5.5 hours. 
 
Can probably cut the broadband down to about 35 mins of 30sec subs for a total integration of 4.8 hours. Anything more doesn't improve the image for me. This will allow me to shoot more than 1 nebula per night sometimes depending on their brightness, but IC443 is fairly dim.
 
QHY268C @ Bin1-3.75 "/pix,  AP130 @ f 4.725, APMach1 unguided.

https://ap-gto.groups.io/g/main/photo/264814/3238572?p=Created,,,20,2,0,0


Re: Will the Mach 2 support .....

Mike Dodd
 

On 6/3/2021 6:43 PM, John Jennings wrote:
This is not an attempt at narrowband
with shrunk or no stars, but rather a composite RGB image from a OSC
camera with colorful background stars.
Is there a link where we can see the image?

--- Mike


Re: VIDEO - Mach2 Right Ascension Belt Adjustment

Harley Davidson
 

You are correct Mike. They are the older design CW's.

tony

On 6/3/2021 10:02 AM, M Hambrick wrote:
Hi Tony

There was something else I noticed in your video that got my attention. Your counterweights have the bronze inserts in them. Are these older counterweights, or did you get them with your Mach 2 mount ?

Those bronze inserts significantly reduce the noise generated from installing and removing the counterweights.

Mike


Re: Will the Mach 2 support .....

John Jennings
 
Edited

The following is my post to our clubs Facebook page. (Texas Astronomical Society of Dallas) An example of fairly fast image acquisition with a OSC CMOS camera. I'm trying to get efficient with my time as I'm getting older. 
 
IC443  the Jellyfish Nebula 
1/15/2021 - Nebula stack -  LeXtreme Pro
1/18/2021 - Stars stack - IDAS P3
From my backyard in Allen, Texas:
MPSAS 17.8-18.2 / Bortle 8-8.2 (Measured with SQM meter)
 
Finally got the results of my science project I've been working on for the last 3 months. Did not spend more than 2 hours on the work flow today... not including stack time. This is not an attempt at narrowband with shrunk or no stars, but rather a composite RGB image from a OSC camera with colorful background stars. Did spend a month or so on refreshing my math for sky background vs sub length calculations and doing a boatload of testing with filters and my SQM meter.  
 
63 subs @ 240secs (4.2hrs)  LeXtreme Pro
156 subs @ 30 secs (1.3hrs) IDAS P3
Total integration for my Bortle 8+ sky was 5.5 hours. 
 
Can probably cut the broadband down to about 35 mins of 30sec subs for a total integration of 4.8 hours. Anything more doesn't improve the image for me. This will allow me to shoot more than 1 nebula per night sometimes depending on their brightness, but IC443 is fairly dim.
 
QHY268C @ Bin1- 1.26 "/pix, 3.76u pixels,  AP130 @ f 4.725, APMach1 unguided.

https://ap-gto.groups.io/g/main/photo/264814/3238572?p=Created,,,20,2,0,0


Re: Problems using ASI air pro and AP mounts

Roland Christen
 

There is only one way that the keypad can override external instructions: If you have the keypad guide rate set to 1x sidereal but have an external guider set at some lower rate, then if you use the keypad to center an object, it will revert the mount's guide rate back to the keypad setting of 1x sidereal.

I strongly urge for guiding to use the 1x guide rate on your external guide software and not be tempted to set it to some lower value. There is a fundamental reason for that. Lower guide rates do not work well on the stationary Dec axis because it will double or quadruple the time it takes to execute a reversal command. If you want to guide at a more relaxed pace, the proper way to do that is to set the aggressiveness lower, NOT set the guide rate lower. Also: any time you do a calibration run, you need to have the guide rate at 1x sidereal.

Roland

-----Original Message-----
From: Roland Christen via groups.io <chris1011@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Thu, Jun 3, 2021 5:13 pm
Subject: Re: [ap-gto] Problems using ASI air pro and AP mounts


when the HC was then disconnected, the guiding settled down
The keypad does not send anything to the mount during guiding, nor does it modify any outside commands sent to the mount, whether they be slewing or guiding commands, regardless of what app is sending them. The keypad is totally separated from the mount. It serves only to give you a manual method of control, manual meaning what you do with your thumbs on the keypad keys. It is NOT a hand corrector in that it doesn't correct anything.

Rolando

-----Original Message-----
From: Lee Decovnick <ursa@...>
To: main@ap-gto.groups.io
Sent: Thu, Jun 3, 2021 5:02 pm
Subject: Re: [ap-gto] Problems using ASI air pro and AP mounts

Thanks Roland,

I made that errant "assumption" because I observed the AAP guiding program was sending corrections double the necessary "pulse" to the mount - and I had already backed off the pulse length in the app - and when the HC was then disconnected, the guiding settled down to a very narrow and acceptable range in about 5 seconds. 

As I mentioned before, with 3 itterations of AAP's or SharpCap's Polar Alignment app, I can get up to 240 second subs unguided with lovely tight stars.

Lee

--
Roland Christen
Astro-Physics

--
Roland Christen
Astro-Physics


Re: Problems using ASI air pro and AP mounts

Roland Christen
 


when the HC was then disconnected, the guiding settled down
The keypad does not send anything to the mount during guiding, nor does it modify any outside commands sent to the mount, whether they be slewing or guiding commands, regardless of what app is sending them. The keypad is totally separated from the mount. It serves only to give you a manual method of control, manual meaning what you do with your thumbs on the keypad keys. It is NOT a hand corrector in that it doesn't correct anything.

Rolando

-----Original Message-----
From: Lee Decovnick <ursa@...>
To: main@ap-gto.groups.io
Sent: Thu, Jun 3, 2021 5:02 pm
Subject: Re: [ap-gto] Problems using ASI air pro and AP mounts

Thanks Roland,

I made that errant "assumption" because I observed the AAP guiding program was sending corrections double the necessary "pulse" to the mount - and I had already backed off the pulse length in the app - and when the HC was then disconnected, the guiding settled down to a very narrow and acceptable range in about 5 seconds. 

As I mentioned before, with 3 itterations of AAP's or SharpCap's Polar Alignment app, I can get up to 240 second subs unguided with lovely tight stars.

Lee

--
Roland Christen
Astro-Physics


Re: Problems using ASI air pro and AP mounts

Lee Decovnick
 

Thanks Roland,

I made that errant "assumption" because I observed the AAP guiding program was sending corrections double the necessary "pulse" to the mount - and I had already backed off the pulse length in the app - and when the HC was then disconnected, the guiding settled down to a very narrow and acceptable range in about 5 seconds. 

As I mentioned before, with 3 itterations of AAP's or SharpCap's Polar Alignment app, I can get up to 240 second subs unguided with lovely tight stars.

Lee


Re: Back Focus Troubles #Absolute_Encoders

Andrew J
 

Hi Linwood.

I was also concerned about the 2.75" vs. 2.67" back focus and which one I should use. I called Tele Vue and talked with David and asked him which number I should use for a KAF-16200 sensor with 34.6mm diagonal, and he told me to go with the 2.75" value. I hope this is correct, as I already placed my order with Precise Parts for the 2.4" to ATIK EFW3 M54 adapter. If he gave me the wrong number, then I will be about 1mm to long even if leave out the 1mm shim. I will not be a happy camper if they gave me the wrong number.

Good info about guiding from the rings. If I have to go the OAG route then I will have to start all over again with the spacers and likely have to go back to PP again for another adapter. I just receive a new 1600 mount with encoders. I haven't set it up yet as I am still waiting on a few parts. I have been following the unguided discussions on the board with interest. Maybe I will get lucky and be able to image without guiding. 

Thanks for the heads up about the spacing above the saddle. The good news is I think I have a solution already for this issue. I had the same problem with a Lunt 80mm solar scope. If I mounted the scope directly to the saddle the dew shield would hit the saddle and it would interfered with the etalons. To solve this problem I got a Male to Male D Series Adapter (DMM12) and two D Series Female to V Series Female adapters (DPA-VPA-FF) from ADM. This got the scope up off the saddle by about 1.5 inches. It also gave more flexibility when it came to balancing the scope as the Lunt is very back end heavy. Assuming I can get a Vixen style dovetail to fit the Tele Vue Rings, I should be OK. ADM has a VDUP7-V Series dovetail that should work, but I am waiting to get the rings so I can check the measurements with ADM. 

Thanks for all the helpful info.  Glad to hear you are happy with the scope.

Andrew 


Re: Will the Mach 2 support .....

Manusfisch
 

Great post John, thanks for the perspective.

TJF Mobile

On Jun 3, 2021, at 15:53, John Jennings <johnrogerjennings@...> wrote:



[Edited Message Follows]

It's a different world with CMOS sensors. I've been shooting CCD's for 20 years and CMOS for about 1 1/2 years. Fast computers mounted on the telescope, SSD drives, lots of disk space etc. Learning the ins and outs of CMOS gain curves and modes. It's a new world. And they have their issues including flat frame calibrations. But they are here to stay and the performance can be incredibly awesome in certain configurations for certain purposes.  In dark skies with good mounts and tracking, all this is less important.

The read noise being so low and the cameras so fast, makes them ideal for short exposure narrow band imaging in the city. I'm getting some pretty good pictures with CMOS color cameras too with broadband and pseudo narrowband OSC color filters. I have done quite a few calculations and tests of my CCD vs. CMOS cameras. In one calculation/test, a CCD sensor with 9e (typical 9-10) read noise vs. the CMOS 1.5e read noise in my magnitude 18.1 suburban skies (with a broadband light pollution filter) results in a optimal CMOS sensor exposure of 22 seconds vs. 700 seconds for the CCD before the background rears its ugly head. (same level of photons gathered)  Everything was normalized including the pixel size and scope. Really just different read noise parameters.

The 5.94u pixels on my new QHY400C OSC seem to be a pretty good match for my AP155EDF too. And I just like the simpler work flow.  And the raw file size for this full frame larger pixel sensor is a reasonable 48 MB before debayering. I don't think Sony has released a mono version of this sensor. That would be great. The IMX410 is the sensor used in the Nikon Z6.  


Re: Back Focus Troubles #Absolute_Encoders

Don Anderson
 

No problem PM me anytime. 
Do you need my email address?

Don Anderson


On Thursday, June 3, 2021, 09:24:28 a.m. MDT, Andrew Jones <andjones132@...> wrote:


Hi Don.

I read your post with interest. What set me down the path to finally get a definitive answer to how to calculate the Back Focus with Filters is that I just acquired an TV NP101is OTA, the little brother of the NP127is. Your setup is similar to mine. I have an ATIK 16200 with an EFW3 FW. I ordered the TV NP101is Field Flattener (LCL-1069), which per TV has a recommended Back Focus of 2.75" (69.85mm) for the ATIK 16200 34.6mm diagonal sensor. I also ordered TV's Set of 6 Accessory Tubes for 2.4" (TLS-2245). I plan use two of the spacers in the set to for the recommend 1.375" (34.9mm) spacing between the focuser and the FF. The remaining two spacers (0.500" and 0.250") will be placed after the FF. The remaining spacing will have to filled with a Precise Parts Adapter as TV does not make an adapter to go from their 2.4" accessories to the M54 thread I need to connect to the ATIK EFW3. I ordered the the Precise Parts adapter 1mm short and will use the shims included in the 6 piece spacer set to the required Back Focus. I could have just ordered a longer Precise Parts Adapter and skipped the two spacers after FF, but I wanted to keep at least two places where I could add shims as you can only use one shim for each threaded connection. Plus the shorter PP Adapter was cheaper... 

I have some questions about attaching this scope to the 16" DOVELM162 saddle that I have on my AP 1600 mount. I also need to figure out a guide scope solution. I have the 10 x 60 Vario Finder with Quick Release Guider Bracket Kit. (1060VGKIT) that I use with my TEC140, but the only way to use this scope with the NP101is is to commit the cardinal sin of mounting the guide scope to the rings. Although, this may be a less of a sin for a wide field scope. I may have to go OAG route, but I would like to see if I can make what I have work first. Do you mind if I PM you with a few questions about your setup?

Andrew

 


Re: Mount Maintenance for gear wear

Bruce Donzanti
 

Thanks for the quick response- appreciate it.

On Thu, Jun 3, 2021 at 4:34 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:

 Is this that critical for such few hours used?
Not critical in your case.

Rolando


-----Original Message-----
From: Bruce Donzanti <donza2735@...>
To: main@ap-gto.groups.io
Sent: Thu, Jun 3, 2021 3:18 pm
Subject: [ap-gto] Mount Maintenance for gear wear

I have an AP1100 in a permanent observatory on top of my garage parked in position 4.  During the past 3 years, I've only imaged about 120 hrs per year.  I read in the manual to use the keypad to move the scope to park 1 then releasing the clutches and manually moving it to park 4, then recycle the power and then start up from park 4 so you start using the other side of the gear wheels.  Is this that critical for such few hours used?  Also, I no longer have my keypad (I use SkySafari which has park 3 & 4 only) so what is an alternative way to get to park 1?     

--
Roland Christen
Astro-Physics


Re: Mount Maintenance for gear wear

Roland Christen
 


 Is this that critical for such few hours used?
Not critical in your case.

Rolando


-----Original Message-----
From: Bruce Donzanti <donza2735@...>
To: main@ap-gto.groups.io
Sent: Thu, Jun 3, 2021 3:18 pm
Subject: [ap-gto] Mount Maintenance for gear wear

I have an AP1100 in a permanent observatory on top of my garage parked in position 4.  During the past 3 years, I've only imaged about 120 hrs per year.  I read in the manual to use the keypad to move the scope to park 1 then releasing the clutches and manually moving it to park 4, then recycle the power and then start up from park 4 so you start using the other side of the gear wheels.  Is this that critical for such few hours used?  Also, I no longer have my keypad (I use SkySafari which has park 3 & 4 only) so what is an alternative way to get to park 1?     

--
Roland Christen
Astro-Physics


Mount Maintenance for gear wear

Bruce Donzanti
 

I have an AP1100 in a permanent observatory on top of my garage parked in position 4.  During the past 3 years, I've only imaged about 120 hrs per year.  I read in the manual to use the keypad to move the scope to park 1 then releasing the clutches and manually moving it to park 4, then recycle the power and then start up from park 4 so you start using the other side of the gear wheels.  Is this that critical for such few hours used?  Also, I no longer have my keypad (I use SkySafari which has park 3 & 4 only) so what is an alternative way to get to park 1?     


Re: Back Focus Troubles #Absolute_Encoders

ap@CaptivePhotons.com
 

> have an ATIK 16200 with an EFW3 FW. I ordered the TV NP101is Field Flattener (LCL-1069), which per TV has a recommended Back Focus of 2.75" (69.85mm) for the ATIK 16200 34.6mm diagonal sensor.

 

>Although, this may be a less of a sin for a wide field scope. I may have to go OAG route, but I would like to see if I can make what I have work first. 

 

Andrew, one last chime in and I’ll leave you to it…

 

I have that scope, and I think you will love it.  Their backfocus distance recommendation is a bit unusual, as they later say for “larger [than 35mm] formats, use 2.67in instead of 2.75in”.  I talked to TV and when describing my setup with a ASI6200 (which is 35mm format) he kept saying 68mm (2.67” = 67.8mm).  I made the mistake of ordering from precise parts without ability to adjust, but minimum length (with OAG below) and am at 68.7mm, and I think ended up slightly too long based on corner star shape.  So I think you are wise to preserve some additional adjustment room.  In my discussions with them (David Nagler if I recall, not sure) they emphasized a certain amount of variability unit to unit.

 

I added a Celestron OAG – which is definitely NOT made for that OTA’s backfocus as it is really thick at 29mm – as I use it with a C11 as well.  I added it after using a 60mm guide scope on top of the rings.  On the TV double ring set the guide scope was pretty secure there, but I thought I would get better guiding both from a flex standpoint and magnification with an OAG, and I did, improving by maybe 20-30% of RMS (with the usual caveat that there’s so much randomness night to night it is hard to trust such measurements).  Plus I can disconnect from the TV101is and move the entire setup to the C11 without losing focus.

 

My real reason for writing though is the mounting of all this.  The TV Ringset is very short, and does not give any room above the dovetail, indeed negative room to the focus knobs.  And especially with a filter wheel and OAG this is all very back heavy, and I find the dovetail forward enough that the focuser would hit the saddle.  I ended up putting in a pedestal to raise the rings about a half inch or so to allow the focus knobs room if I slid the dovetail forward in the saddle.

 

For perspective here it is mounted on my MyT (still waiting for the AP1100 but the issue will be similar as they don’t even extend above the dovetail much less saddle without some kind of pedestal).

 

Linwood

 


Re: Will the Mach 2 support .....

John Jennings
 

The attached image was just a test shot during flattener collimation. Not the best processing etc., and was shot in my bortle 8 / 2" + sky. It's to illustrate how fast CMOS cameras can be.

37 subs@ 120s - 74 min
Allen Texas - Bortle 8
MaximDL, ASTAP, StarTools, Photoshop
AP Mach1, AP155 f/7.18 with flattener, 1.11 asecs/pix, big crop
QHY410C full frame CMOS color 5.94U pixels
IDAS P3 filter


Re: Will the Mach 2 support .....

John Jennings
 
Edited

It's a different world with CMOS sensors. I've been shooting CCD's for 20 years and CMOS for about 1 1/2 years. Fast computers mounted on the telescope, SSD drives, lots of disk space etc. Learning the ins and outs of CMOS gain curves and modes. It's a new world. And they have their issues including flat frame calibrations. But they are here to stay and the performance can be incredibly awesome in certain configurations for certain purposes.  In dark skies with good mounts and tracking, all this is less important.

The read noise being so low and the cameras so fast, makes them ideal for short exposure narrow band imaging in the city. I'm getting some pretty good pictures with CMOS color cameras too with broadband and pseudo narrowband OSC color filters. I have done quite a few calculations and tests of my CCD vs. CMOS cameras. In one calculation/test, a CCD sensor with 9e (typical 9-10) read noise vs. the CMOS 1.5e read noise in my magnitude 18.1 suburban skies (with a broadband light pollution filter) results in a optimal CMOS sensor exposure of 22 seconds vs. 700 seconds for the CCD before the background rears its ugly head. (same level of photons gathered)  Everything was normalized including the pixel size and scope. Really just different read noise parameters.

The 5.94u pixels on my new QHY400C OSC seem to be a pretty good match for my AP155EDF too. And I just like the simpler work flow.  And the raw file size for this full frame larger pixel sensor is a reasonable 48 MB before debayering. I don't think Sony has released a mono version of this sensor. That would be great. The IMX410 is the sensor used in the Nikon Z6.  


Re: Back Focus Troubles #Absolute_Encoders

Andrew J
 

Hi Don.

I read your post with interest. What set me down the path to finally get a definitive answer to how to calculate the Back Focus with Filters is that I just acquired an TV NP101is OTA, the little brother of the NP127is. Your setup is similar to mine. I have an ATIK 16200 with an EFW3 FW. I ordered the TV NP101is Field Flattener (LCL-1069), which per TV has a recommended Back Focus of 2.75" (69.85mm) for the ATIK 16200 34.6mm diagonal sensor. I also ordered TV's Set of 6 Accessory Tubes for 2.4" (TLS-2245). I plan use two of the spacers in the set to for the recommend 1.375" (34.9mm) spacing between the focuser and the FF. The remaining two spacers (0.500" and 0.250") will be placed after the FF. The remaining spacing will have to filled with a Precise Parts Adapter as TV does not make an adapter to go from their 2.4" accessories to the M54 thread I need to connect to the ATIK EFW3. I ordered the the Precise Parts adapter 1mm short and will use the shims included in the 6 piece spacer set to the required Back Focus. I could have just ordered a longer Precise Parts Adapter and skipped the two spacers after FF, but I wanted to keep at least two places where I could add shims as you can only use one shim for each threaded connection. Plus the shorter PP Adapter was cheaper... 

I have some questions about attaching this scope to the 16" DOVELM162 saddle that I have on my AP 1600 mount. I also need to figure out a guide scope solution. I have the 10 x 60 Vario Finder with Quick Release Guider Bracket Kit. (1060VGKIT) that I use with my TEC140, but the only way to use this scope with the NP101is is to commit the cardinal sin of mounting the guide scope to the rings. Although, this may be a less of a sin for a wide field scope. I may have to go OAG route, but I would like to see if I can make what I have work first. Do you mind if I PM you with a few questions about your setup?

Andrew

 


Re: Problems using ASI air pro and AP mounts

Roland Christen
 


I find that I literally must unplug my AP hand controller from the CP4 - as BOTH AAP and the hand controller are send tracking signals ... no kidding.
The AP hand controller sends NO signals. It is totally silent unless you, the user, pushes any of the buttons.

Roland


-----Original Message-----
From: Lee Decovnick <ursa@...>
To: main@ap-gto.groups.io
Sent: Wed, Jun 2, 2021 11:14 pm
Subject: Re: [ap-gto] Problems using ASI air pro and AP mounts

AAP guiding is frustrating ..I find that I literally must unplug my AP hand controller from the CP4 - as BOTH AAP and the hand controller are send tracking signals ... no kidding. I also have set my AAP Dec and RA aggression to 10% or 15%.  Dithering does work well. And as always, your Polar Alignment needs to be dead on, and the AAP PA program works pretty darn well for me...

Lee

--
Roland Christen
Astro-Physics


Re: VIDEO - Mach2 Right Ascension Belt Adjustment

M Hambrick
 

Hi Tony

There was something else I noticed in your video that got my attention. Your counterweights have the bronze inserts in them. Are these older counterweights, or did you get them with your Mach 2 mount ?

Those bronze inserts significantly reduce the noise generated from installing and removing the counterweights.

Mike

2581 - 2600 of 81492