Tuesday, 17 November 2015

Total Eclipse Camera Selection

I have been using a Sony NEX5N for the past two years and have reached the conclusion that while useful, it does not do what I want in terms of total solar eclipse photography.

Screen display: In summary, it is not useful outside during the day. An eyepiece type arrangement would be preferred. Trying to use it at night is also a problem unless the target is very bright. My initial thought was that it would flip up for sky photography and would be useful in that regard. The problem is that it does not flip up far enough and getting a good focus can be very difficult. I had to set the display on the dimmest setting too. During a total solar one does not have such luxury time. An eyepiece display is preferred, especially one that can work at a right angle from the imager plane.

ISO/ASA results: Trying to do higher ISO settings has not been successful. The resulting images are grainy. Newer technology will be nice in that regard. A friend of mine showed results of images at 12800 ISO which were quite good in terms of grain.

Resolution: My camera is a couple years old. This technology is evolving quickly. Newer camera chips have better resolution and can work with lower light conditions.

Lens set: My lenses are all Canon, even my T-adapter has a Canon type mount (as well as an old-school screw, originally I bought it to use with a Honeywell Pentax). Canon lenses using autofocus are nice for bright objects but don't work well in dim light. Manual focus is still best, especially for solar eclipses.

Saturday, 14 November 2015

Pre Dawn Planet Show

During the month of October 2015 the planets Venus, Jupiter, Mars, and Mercury were all visible in the pre-dawn sky.

Sunrise (and sunset) are excellent times to practice your eclipse photographic set up for wide angle sky views. The colors seen around the horizon match up with those observed during an eclipse. You can experiment with various ASA/ISO and exposure settings to see how your rig behaves. Find the exposure setting that will produce colorful results that also show the brighter planets and stars.

While not welcomed during a total solar eclipse, the clouds do add some drama to the pictures as well as some foreground to establish the setting and/or location. Trees make excellent foreground objects (when far enough away for your camera lens) and can really enhance the image with a stark contrast. Out of focus foreground objects require careful thinking as this distracts from the main image - the sky.

Friday, 13 November 2015

Green Flash

Have you ever seen a Green Flash at sunset (or sunrise)?

Here is a video compilation of various green flashes observed in Negril Jamaica. The camera used was a Sony NEX5N with a Canon 400mm lens on a tripod. We see green flashes often (the advantage of living on the western coast in the tropics) at sunset. It may even be raining overhead but clear off in the sea and we will see a green flash. But when the atmosphere is calm and mostly clear we get some great flashes.

The video has no sound and I do hope it is not too sliced up by the data compression.


September Lunar Eclipse

This past September there was a lunar eclipse visible in Jamaica and we had partly cloudy sky for the event. My wife and I moved to a new place that has not had Internet available which is why I am tardy in sharing our results. As of this week, we have access and so here is an image from the eclipse.

The image was obtained using a Sony NEX5N attached to a Canon 400mm telephoto lens. And it was cropped to just show the eclipse area.

In the above image we can see the shadow of the Earth as a curve along the right edge of the Moon. Where the lunar surface is brightest there is still some sunlight being reflected back. The orange-red portion of the Moon is illuminated by light from the Sun passing through the Earth's atmosphere.

Of particular interest is the light blue color visible near the upper right. This color shows up better in photographs than with the naked eye.

The light blue color is the result of solar light passing through ozone.

Sunday, 8 November 2015

Four months till the next TSE!

In just four short months eclipse chasers will be converging on Indonesia and other places in the Pacific Ocean to view a Total Solar Eclipse. This eclipse will have a greater duration than the eclipse of 2017 across the USA but it much harder to access. Land fall is limited to a few Indonesian islands and mostly crosses the ocean. Cruise ships will be sailing into the path of totality near Indonesia and a few charter vessels will be in the open sea.

One unique opportunity for a few people is a flight out of Alaska that will intersect the eclipse path. Joe Rao of New York has been lobbying Alaskan Airlines to modify a flight departure and with the help of Glenn Schneider has been successful. Flight 870 will attempt an intercept of the shadow path and if all goes well a few lucky passengers will get a great view out the window. We wish them luck.

Friday, 25 September 2015

Total Lunar Eclipse - camera selection briefing

Small telescope (1300mm)

So you want to take a picture of the lunar eclipse? One question any expert will ask is what type of camera you have available for the event. Another is just what you want to photograph.

To produce a nice close up of the eclipsed Moon, you will want a small telescope or telephoto lens. The Moon appears to be about half a degree in size (yes, even during a so called Super Moon it appears that large). Using that information, the next step is to determine the field of view of your lens system and camera, which is a bit technical. This can be done with a formula (explained at https://www.eclipse-chasers.com/photo/Photo4.shtml) involving the size of your camera image plane (chip size) and the effective focal length. Cutting to the chase, I recommend a lens with a focal length of 200mm and more to show the Moon best.

April 2015 Lunar eclipse - EFL of 100mm
A frequently asked question is whether or not a camera phone can be used. The answer is an emphatic yes, just don't expect the greatest detail of the Moon and you will want to try several times before you get a nice image. The small lens will not capture much detail of the Moon however you can get great images of people and the eclipse. Just don't use the flash without warning others first!

When using a telescope or long telephoto lens you will need to manually set the exposure. Eclipses confuse automatic camera settings. As the eclipse darkens, longer and longer exposures will be needed to reveal details as seen in the image below. Both images of the eclipse were taken at roughly the same time, just different exposure settings. Note that the longer exposure washed out the illuminated surface while bringing out the eclipsed side where the shorter exposure shows the lit surface and a completely blacked out eclipse area.

A very nice to have is a tripod or fixed base for a longer exposure. Hand held images will show some blurring since it is nearly impossible to hold the camera perfectly still that long. Bracing yourself agains a building or wall might work if you are lucky but I strongly recommend a tripod or set it on the ground facing the right way and hope for the best.

Another trick is to use the delay feature (if available) on your camera. Point the camera at the eclipse and start the exposure. After a brief count down, the camera will take the image. The delay allows vibrations to settle and will result in sharper looking images. Using this method you can take an image that includes both yourself and the eclipse!

So the bottom line? If you want to try taking an image of the lunar eclipse, a nice big camera and lens on a tripod is best. But don't let that dissuade you from trying! I have seen plenty of great images taken with small camera phones. You just need to take a lot of images and have a lot of luck!

Saturday, 19 September 2015

Bug Fix 1988 Eclipses

There was a file mix up in the Mar and Sep 1988 eclipses. I think I have sorted it out, but if you are one of the few that saw either, please double check your log and let me know if there are any problems.

I am not sure how the old file snuck back in, but it can happen. We had to restore from back ups a few times after attacks on the server and issues with a power supply. So I am going to presume that is when it re-appeared.

Update 22-Sep-15 - found anomalies with ASE 2013 thanks to Joe Cali. Those have been corrected. Please check your log to make sure it is correct and let me know if not!

Sorry for any confusion.