ROT2 command of IRIS

[Merrill55]

Hi, Ken Harrison,

I'm Toshio Ohnishi. I'm old amateur Spectrohelioscope maker.
Recently, I made short spectroheliograph. This is not completed yet.
I have some trouble about IRIS of C.Buil.
I using AZW174MM as CCD.I do't know to use ROT2 command.
What can I should do to ROT2 command? ROT command is OK.

Toshio Ohnishi

[Merlin66]

Toshio,
Welcome to the group!

I have limited experience with IRIS but will investigate the ROT2 command for you.
I would recommend that you download Wah!'s SLiM (Spectral Line Merge) program from the library section; it's much easier to use and is very effective.

Can you give us more detail of your SHG.

[marktownley]

Welcome Toshio! I always admire your SHG images on facebook, glad you found your way here

Mark

[highfnum]

welcome Welcome Toshio!
I also saw your recent post on daystar filters FB

Yes a lot of us use Wah! merge program

[Merlin66]

Toshio,
Looking at the command line structure of ROT2.....
Command: ROT2 [IN] [OUT] [XC] [YC] [ANGLE] [NUMBER]
where
[IN] - generic name of the sequence of images to be treated (e.g. Solar_in)
[OUT] - generic name of the rotated images (e.g. Solar_out)
[XC], [YC] - the pixel coordinates of the centre of rotation (e.g. 150, 400)
[ANGLE] - the applied rotation in degrees (e.g. 8)
[NUMBER] - the number of images in the sequence (e.g. 25).

Example
ROT2 Solar_in Solar_out 150 400 8 25

[Merrill55]

Thank you all.

Telescope 80mm FL=910
Collimator(Camera) 70mm FL=700
Grating 1800L/mm 5000A Brazed
Slit width=20micron
CCD ASI174mm

The SLIM is not work in my windows10.
When I push Merge button,it shows 'System.NullReferenceException'.

[Merlin66]

Toshio,
Hmmm
I think that means your AVI is larger than the 2Gb limit.
You need to use VDub to rope around the line of interest to reduce the file size.
Your SHG looks very impressive!!

[Merrill55]

Thank you Ken,

Even if 451MB,I got an error in SliM.
I do'nt understand this error message.

[Merrill55]

OK !
VDab-> SliM I could make 1 frame!
How can I save this frame?
I'm a beginner in this procedure.

[Merrill55]

I found out the new one in same old.avi folder.
I should become aware of saving method. So sorry!

[highfnum]

SliM auto creates a TIFF file with same name as avi that went in - should be in same directory

[Merrill55]

Thank you highfnum.
I waiting for next clear morning.

[highfnum]

I saw you are using binoviewer in optical path -- what is it for?

[Merrill55]

The binocular device is used to facilitate optical axis adjustment.
In order to use it as a spectrohelioscope, a littrow type optical system is not appropriate.
Off-axis light causes distortion.

[Merlin66]

Toshio,
I have a similar set-up using a 100/1300 scope an a 70/900 Littrow 1200 l/m grating spectrograph.
The only distortion is the slant of the absorption lines within the spectrum which is easily fixed. A similar system is used by Fulvio Mete (http://www.lightfrominfinity.org/Hirss% ... scopio.htm)
Do you have other distortions??

[Merrill55]

No, I have not other distortion.
My aim is to make a telescope to observe the sun by my eye.
But I have not succeeded yet.

[Merlin66]

Toshio,
Understood.
Which 20 micron entrance slit do you use - Thorlabs?
A SHS needs vibrating slits or Anderson prisms - see Fred's book (files area of the Yahoo Astronomical Spectroscopy group) or Chapter 11 of "Imaging Sunlight" (http://www.springer.com/gp/book/9783319248721)

[Merrill55]

My Hale vibrating slit made by razor blade.

H-alpha photo by old SHS is as follow.

[Merlin66]

Toshio,
Well done.
It looks like you understand the design requirements.
Look forward to seeing your future results.

[Montana]

Wow! fabulous image

Alexandra

[highfnum]

that photo with SHS how was that taken
that's NOT using a merge program - correct?

[Merrill55]

My old SHS is as follows,
I need not use 'merge' soft.

[highfnum]

Wow impressive!
So the 2 slits spin around I assume
To build image?

Kind of like mr Hale did way back when

[Merlin66]

John,
The small pin on the motor in the slot "oscillates" the two slit plates back and forth. See "Imaging Sunlight", sect 11.2.1 for more details.

[Merlin66]

Toshio,
Very nice results from a very nice SHS. Impressive!
Well done.