M45 tricolour pic

cometcatcher (Kevin) · #1 19-01-2005, 12:55 AM

This is about as faint as I can go with the mintron video camera.

1000 x 1.25 second frames per channel - Orange, Yellow, Blue all up 3000 frames or about an hour's worth with a 135mm lens.

I'm somewhat disappointed that I didn't get more nebula, but at the same time think it's a pretty pic just the same.

iceman (Mike) · #2 19-01-2005, 06:30 AM

It is very pretty Kevin, nice job!

What causes the artifacts on your image? Is it the video camera itself, or compressing it down to jpeg?

gbeal · #3 19-01-2005, 09:00 AM

Kevin,
that is some serious work, 1000 shots. I would say that you may have exhausted the Minitron.
Gary

cometcatcher (Kevin) · #4 19-01-2005, 02:34 PM

I was thinking of putting a fan in the thing since the night time temps are pretty hot lately. It never drops much below 30 degrees and the hot pixels are bad even at 1 second integrations.

The dark rings around the bright stars are artifacts from the analogue video. They become more prominent with the normal course of processing for astro pics. Can't do anything about them that I know of. This camera was never designed for astronomy. However I've seen similar artifacts from bright stars (no doubt with a different cause) from the Lowell 13 inch Schmidt camera.

I just have to live with them until someone brings out a nice astro camera for $500 and I don't mean the DSI.

Robby · #5 19-01-2005, 02:46 PM

Very nice Kevin,
That is certainly a good effort! Well done.

cometcatcher (Kevin) · #6 19-01-2005, 03:29 PM

But it should be better. Compare this unfiltered photo taken through the 10 inch f4.5 scope of M20. Doesn't seem to be short of sensitivity for nebula here.

Perhaps the colour filters are knocking the light down too far. And summer doesn't help. I can't wind the frame integration up as far as in winter due to hot pixels.

Mick (Michael) · #7 19-01-2005, 08:51 PM

Beautiful images Kevin.

Nortilus (Josh) · #8 20-01-2005, 04:14 PM

Very nice indeed...

cometcatcher (Kevin) · #9 21-01-2005, 12:17 AM

Took most of the afternoon but have now installed a small computer fan. Tests show that it does make a difference.

iceman (Mike) · #10 21-01-2005, 06:09 AM

Excellent! Can't wait to see the new images!

[1ponders] (Paul) · #11 21-01-2005, 11:05 AM

Good show Kevin. I especially like the Triffid shot. What prog did you use for the processing of the M45 shot?

cometcatcher (Kevin) · #12 21-01-2005, 09:39 PM

For M45 I took 3 avi's of 1000 frames each through O-Y-B filters. Each avi was stacked separately in Registax with dark frame subtract (1000 darks stacked) and output to 16bit per channel TIFF files. Each of the 3 TIFF files had curves/levels applied in Adobe Photoshop 6 before going to Corel Photopaint 8 for removal of existing hot pixels that the dark in Registax didn't take out.. The 3 files were loaded back into Photoshop where each were matched with levels/curves/lasso in bright spots to make them as even as possible.

The next step for RGB combining is best described in this link http://www.employees.org/~jmulchin/lrgb.html

That's pretty much how I did it minus the luminance layer. The final RGB layer was flattened and final levels/curves/colour balance applied.

It only took 3 hours.

[1ponders] (Paul) · #13 21-01-2005, 10:42 PM

Only 3 hours! Good onya Kevin

ving (David) · #14 24-01-2005, 04:47 PM

purdy m45 shot!
love good olde m45 ya know!

ballaratdragons (Ken) · #15 05-02-2005, 03:24 PM

<font size="3" color="red"><b>Nice photo!</b></font>