Re: Repositioning the camera angle


Oct 22, 2002

 


----------------------------

#4384 Oct 22, 2002

Can someone please enlighten me how to interpret the camera angle shown

in the MaxIm DL/CCD V3 Autoguider Settings / Manual Calibration window.

It does not seem to relate to North being 0 deg. and increasing to the

East. For example, I set my ST-7 camera so that the guide chip was

approx. 40 degrees to the East of North. After doing a guider

calibration, the angle shown in the manual calibration window was shown

as 140 degrees. I derive the angle from a planetarium program, that puts

an image of the camera chips on the screen, to suit a guide star and

then set the camera with a protractor. I can't think of any relationship

between the camera angle on the sky and the angle displayed. Does it

have anything to do with my being in the southern hemisphere?



Are you there Doug George?



Kevin Cooper.



----------------------------

#4390 Oct 23, 2002

Kevin Cooper wrote: > Can someone please enlighten me how to interpret the camera angle shown

> in the MaxIm DL/CCD V3 Autoguider Settings / Manual Calibration window.

> It does not seem to relate to North being 0 deg. and increasing to the

> East. For example, I set my ST-7 camera so that the guide chip was

> approx. 40 degrees to the East of North. After doing a guider

> calibration, the angle shown in the manual calibration window was shown

> as 140 degrees. I derive the angle from a planetarium program, that puts

> an image of the camera chips on the screen, to suit a guide star and

> then set the camera with a protractor. I can't think of any relationship

> between the camera angle on the sky and the angle displayed. Does it

> have anything to do with my being in the southern hemisphere?



The value depends on the camera rotation angle and which way the autoguider

relay wires are hooked up to the mount. There are quite a few possible

permutations of the relay wire connections. (Also be aware that a German

Equatorial mount will produce different directions when you flip over the pier.)



Because there are so many free parameters, the sign conventions we used can be

considered to be entirely arbitrary. The display will show approximately zero

degrees if the first move of the star is "right" relative to the CCD camera.

Try playing with the settings in the Simulator; it allows you to "rotate" the

camera to various angles, as well as flip the sense of the X axis.



Your number of 140 is 40 degrees away from 180, so I suspect your star goes "up"

on the first calibration cycle.



Doug



---------------



Doug George

dgeorge@...



Diffraction Limited

Makers of Cyanogen Imaging Products

www.cyanogen.com



100 Craig Henry Drive, Unit 106,

Ottawa, Ontario, Canada, K2G 5W3



Phone: (613) 225-2732

Fax: (613) 225-9688



---------------



----------------------------

#4392 Oct 23, 2002

Thanks Doug, You suspect correctly.



Kevin.



Douglas B. George wrote:

>

>

>Your number of 140 is 40 degrees away from 180, so I suspect your star goes "up"

>on the first calibration cycle.

>

>Doug

>

---------------

>

>Doug George

>dgeorge@...

>

>Diffraction Limited

>Makers of Cyanogen Imaging Products

>www.cyanogen.com

>

>100 Craig Henry Drive, Unit 106,

>Ottawa, Ontario, Canada, K2G 5W3

>

>Phone: (613) 225-2732

>Fax: (613) 225-9688

>

---------------

>

>

>

>To unsubscribe from this group, send an email to:

>MaxImDL-unsubscribe@yahoogroups.com

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>

>

>Your use of Yahoo! Groups is subject to docs.yahoo.com/info/terms/

>

>

>.

>



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#18060 Apr 27, 2005

Good morning, Doug. This question has to do with potential scripted

operations with a rotator.



1) Assume the guide camera orientation is 0 degrees when the guider

calibration is run. If the camera angle is changed physically and

MaxIm is notified of the change via the CCDCamera.GuiderAngle = x

command, is the original guider calibration still valid?



2) Or, does it require doing another guider calibration at the new

camera (rotator) angle?



3) If it does require a new calibration (that's my suspicion)

couldn't this be done mathematically instead of physically?



4) MaxIm could do the math, or I assume the script could do the math

and alter the values in CCDCamera.GuiderXSpeed and

CCDCamera.GuiderYSpeed.



Can you shed some light on this subject?



Thanks in advance.



Jim McMillan



----------------------------

#18075 Apr 27, 2005

--- In MaxImDL@yahoogroups.com, "maximccd" dgeorge@c...> wrote:



Thank you, Doug.



That makes it easy!



Jim



> > 1) Assume the guide camera orientation is 0 degrees when the guider

> > calibration is run. If the camera angle is changed physically and

> > MaxIm is notified of the change via the CCDCamera.GuiderAngle = x

> > command, is the original guider calibration still valid?

>

> That should work. You might have to do some experiments just to make

> sure that the angle is measured in the same direction.

>

> Doug George

> Diffraction Limited







----------------------------

#20409 Sep 13, 2005

With the need to adjust the angle of the camera periodically for a shot

to frame the subject correctly, sometimes I would like to be able to

log the camera angle so that I could go back for a run of additional

frames on that subject.



Is there a way to log ones camera angle today or log it some where in

the FITs header?



I'm currently leaving a "Notes" text file in the sub-directory but that

seems somewhat old fashion way of maintaning a log.



Thanks in advance.



Bob



----------------------------

#20411 Sep 13, 2005

Use Pinpoint to solve the plate. The camera angle is one of the terms

recorded in the header (with very high accuracy).



Chris



*****************************************

Chris L Peterson

Cloudbait Observatory

www.cloudbait.com



----- Original Message -----

From: "Robert Anderson" bob@...>

To: MaxImDL@yahoogroups.com>

Sent: Tuesday, September 13, 2005 7:51 PM

Subject: [MaxImDL] Wish List item = Note Attachment for camera angle





> With the need to adjust the angle of the camera periodically for a shot

> to frame the subject correctly, sometimes I would like to be able to

> log the camera angle so that I could go back for a run of additional

> frames on that subject.

>

> Is there a way to log ones camera angle today or log it some where in

> the FITs header?

>

> I'm currently leaving a "Notes" text file in the sub-directory but that

> seems somewhat old fashion way of maintaning a log.

>

> Thanks in advance.

>

> Bob



----------------------------

#20415 Sep 13, 2005

Thanks Chris.



Is that the CROTA1 & CROTA2 information, (Axis 1 & 2 rotatio in

degrees) that is added upon doing a Pinpoint analysis?



Cheers



Bob

--- In MaxImDL@yahoogroups.com, "Chris Peterson" clp@a...> wrote:

> Use Pinpoint to solve the plate. The camera angle is one of the

terms

> recorded in the header (with very high accuracy).

>

> Chris

>

> *****************************************

> Chris L Peterson

> Cloudbait Observatory

> www.cloudbait.com

>

>

> ----- Original Message -----

> From: "Robert Anderson" bob@t...>

> To: MaxImDL@yahoogroups.com>

> Sent: Tuesday, September 13, 2005 7:51 PM

> Subject: [MaxImDL] Wish List item = Note Attachment for camera angle

>

>

> > With the need to adjust the angle of the camera periodically for

a shot

> > to frame the subject correctly, sometimes I would like to be able

to

> > log the camera angle so that I could go back for a run of

additional

> > frames on that subject.

> >

> > Is there a way to log ones camera angle today or log it some

where in

> > the FITs header?

> >

> > I'm currently leaving a "Notes" text file in the sub-directory

but that

> > seems somewhat old fashion way of maintaning a log.

> >

> > Thanks in advance.

> >

> > Bob



----------------------------

#20416 Sep 13, 2005

Exactly (and you only need one or the other- something is very wrong if you

have a different angle of rotation about X then you do about Y). And the

CDELT values are easily read as your pixel scale. Position angle, focal

length, and pixel scale are also reported directly by Pinpoint before you

close the dialog. Solving all your plates is a good idea- it lets you use

Maxim's astrometric information mode to get the coordinates of any point in

the image.



Chris



*****************************************

Chris L Peterson

Cloudbait Observatory

www.cloudbait.com



----- Original Message -----

From: "Robert Anderson" bob@...>

To: MaxImDL@yahoogroups.com>

Sent: Tuesday, September 13, 2005 9:31 PM

Subject: [MaxImDL] Re: Wish List item = Note Attachment for camera angle





> Thanks Chris.

>

> Is that the CROTA1 & CROTA2 information, (Axis 1 & 2 rotatio in

> degrees) that is added upon doing a Pinpoint analysis?

>

> Cheers

>

> Bob



----------------------------

#31737 Mar 27, 2008

If my image which I plate solve has a angle of 90 degrees, I want to

get it as close as I can. So I take an image and do a pinpoint plate

solve in Maxim. However, I have to put in the angle (well I use the

calibrate and set it to auto) in the telescope control. If I don't do

that, the pinpoint plate slove does not work.



Not sure why they are related but that takes more time than I was

hoping for. I guess I could use CCD Commander and plate solve, but I

thought this would easiler.



dean



----------------------------

#31746 Mar 28, 2008

I've talked to Bob Denny about this. He is the creator of the

PinPointLE plate solving engine that comes with Maxim. He says that

pinpoint is independent of rotation angle or even the reverse images

you get from newtonians or cassegrains.



Initially, I had trouble doing plate solves reliably with my DSLR

images. Almost invariably, the problem had to do with image scale.

You need to get that as close as possible. Once I finally got pinpoint

to reliably plate solve, I found that my image scale wasn't quite what

I thought it was. For example, my 600mm refractor was showin 580mm FL

from the plate solve. My 980mm TEC140 plate solves to 984.7mm focal

length. Also, Bob said that he requires only 7 stars to be able to

make a plate solve. Anyway, those are the kinds of things you should

expect. Bob says that a certain level of forgiveness is allowed for in

PinPoint regarding the image scale.



To make it easier in Maxim, make sure that the File > "Settings..." > "Site and Optics" > "Main Telescope" > "Focal Length" is correct

before you start taking the images. This will ensure that the image

scale is correct. You probably also ought to do a Telescope > Center >

Calibrate, so that the positon angle is set. I'm not sure if that has

an effect or not.



Dave

--- In MaxImDL@yahoogroups.com, "Dean Salman" cluster@...> wrote:

>

> If my image which I plate solve has a angle of 90 degrees, I want to

> get it as close as I can. So I take an image and do a pinpoint plate

> solve in Maxim. However, I have to put in the angle (well I use the

> calibrate and set it to auto) in the telescope control. If I don't

do

> that, the pinpoint plate slove does not work.

>

> Not sure why they are related but that takes more time than I was

> hoping for. I guess I could use CCD Commander and plate solve, but I

> thought this would easiler.

>

> dean

>







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