DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Under Water, Over Land (https://www.dvinfo.net/forum/under-water-over-land/)
-   -   Test clip: Video of stars (https://www.dvinfo.net/forum/under-water-over-land/107110-test-clip-video-stars.html)

Grant Sherman November 2nd, 2007 11:44 AM

Test clip: Video of stars
 
Here's a short clip that shows the stars of Orion at different focal lengths. The quality's a bit "myspace" :-)

http://myspacetv.com/index.cfm?fusea...deoid=21280051

All shots were (probably) 1/6s shutter, +18dB gain, open iris. Shot at 4:3, 25p with Canon XL2.

1. 3x Zoom lens at wide angle, you can hardly see the stars in this one.
2. 20x lens at wide angle. Better.
3. 20x at just short of full zoom (better framing of the stars of the Sword).
4. 20x full zoom.

The stars that you can see in 3 & 4 are almost undetectable in the first two shots. So the best things to video appear to be clusters of stars. Pleiades and the Sword are two of the best and brightest.

Russ Holland November 2nd, 2007 12:13 PM

I would love to see stills of these taken from the footage. The Myspace compression may have wiped out alot of detail and "blackness" so can you post still images of each test for us please? Myspace just doesn't do it justice!

Thanks,

Russ

Brendan Marnell November 2nd, 2007 01:22 PM

Quote:

Originally Posted by Russ Holland (Post 769117)
I would love to see stills of these taken from the footage. The Myspace compression may have wiped out alot of detail and "blackness" so can you post still images of each test for us please? Myspace just doesn't do it justice!

Thanks,

Russ

I'd second that.

Grant Sherman November 3rd, 2007 01:09 AM

4 Attachment(s)
Here's the frame grabs.

Planets are also a good target and all of the eight major planets are on the right side of the sun at the moment (plus two dwarf planets). Jupiter is still around in the early evening. Neptune and Uranus are also evening objects, but they set slightly later than Jupiter so you'll have more time to find them. Mars rises at around 10pm GMT in the constellation of Gemini. Saturn and Venus are early morning objects in Leo. Venus is brilliant in the morning sky at the moment and you should be able to see that it's at half phase. Mercury is also a morning object for Northern Hemisphere observers. It reaches it's greatest apparent distance from the sun on the morning of the 7th Nov. Ceres and Eris are possible targets but require more technology to image. If you can get image Neptune then you should be able to image Ceres. I've only been able to capture them with my dSLR.

Grant Sherman November 3rd, 2007 01:49 AM

1 Attachment(s)
Here's some still images of planets.

Mat Thompson November 3rd, 2007 06:07 AM

I'm liking those planets images !! What were the Mars, Jupiter and Saturn images shot with and at what focal length/conditions ?

Great stuff!

Grant Sherman November 3rd, 2007 06:47 AM

Mars, Jupiter and Saturn were shot with a f=1300mm telescope and a webcam. The Jupiter image is a single frame. The Mars and Saturn images were processed using the frame-stacking program Registax. Stacking takes avi file and aligns and stacks the individual frames to form the final image. The Mars image was stacked using the best 500 frames of 1000.

Mat Thompson November 3rd, 2007 11:19 AM

Interesting stuff. I'm not quite sure I understand the technicalities completely but It certainly has very cool results. I hope we see some of this in UC6!

Grant Sherman November 4th, 2007 03:32 AM

Naked eye comet
 
2 Attachment(s)
There's a naked eye comet in the northern sky. Comet 17/P Holmes is normally too faint to detect. On the 24th October there was an explosion on the comet. This released a cloud of gas, ice and dust that was almost the diameter of the sun.

Here's a photo that I took with a dSLR. 5s 80mm ISO1600 f3.4.

Trond Saetre November 4th, 2007 01:36 PM

Grant,

Thank you very much for sharing.
Why didn't I think about zooming to tele instead of wide in my attempts?
I'll definitely have this in mind when trying to film stars next time.


All times are GMT -6. The time now is 08:39 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network