Monday, November 23, 2015

New monochromatic camera, setting up

Got a new one, I guess not many people use it, it's based on CMOS which is quite risky.  I don't know if it has Newton's ring... if there is, I will use the drift and average method.

It has 5M pixel so that I no longer need to go for barlows and the chip is quite big so that mosaic work is minimized.

The problem becomes frame rate due to the large volume of data.

With my Windows 8.1 tablet, it could go up to 5+ fps when saving to the internal SSD... it drops to lower than 1fps when saving to a good micro SD card, but then I know it's due to the internal card reader rather than the card itself.

When my Eee PC, the frame rate is slightly less than 3fps....

So, the tablet will be used for imaging, and I will have to free up space from the internal SSD to store the video clips.  I was thinking to remove the android partition which I seldom use.  But then I will want to make a partition dump as backup.


First light, since the frame rate is low, it could be hard to gather too many frames to stack, for example, to stay within a 100s time window, we could have only around 500 frames to play with:-

Note that the camera driver will insert time stamp on the upper left... !  Anyway, most of the newton's ring is averaged out except on the upper right area... I shall explore way to improve.  The amount of detail is nice, and we don't need to go for mosaic.


To free up extra space for AVI storage, I have decided to erase the Android of my Teclast.  However, I reserve the right to go back later, so I only remove the user data partition which is around 16G in size.  Before formatting that partition, I use:

to backup the partition image, so when I need it again, I will restore that particular partition.  Actually, I have another Android tablet so I will not use that on my Teclast.  And in fact, the Teclast Android is buggy, for example, the wifi password would not be saved and I will need to enter it every time after rebooting.

By removing that partition and reformatting to NTFS, we could use it for image capturing but then I found that the drive letter than I assigned via Computer Management (Windows 8.1) will be lost every time I reboot.  After some investigations, I found that partition was set hidden.  To unhide it, use diskpart commandline to unhide... select disk, select partition, partition detail, attribute volume set/clear hidden

too cryptic?  not already for old age IT guy.


To remove the Newton's ring, I will try to DIY a tilting device and there are some C mount extension tube from taobao, and they might be good candidate for the modification work, and it might be a good idea to sandwich a small reducer lens between the tilting mechanism so that I could have full disc in a single shot!

Before making the tilting adapter, I will try to image the sun without tracking...  i.e. just let the solar disc drift from one side of the CMOS to the other side slowly, and hopefully, the rings will be average out.

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