Perseids Peak Day One

This multi-colored meteor streak was the first of three bright meteors I captured from Bowman Woods Park in Cedar Rapids, Iowa during the pre-dawn hours on Saturday, August 12, 2017--part of the Perseids Meteor Shower. This particular meteor--captured at 4:10 am CDT--featured a trailing vapor trail, but the trail was rendered invisible to the camera by the glare of the waning gibbous moon, whose light wash can be seen in the image at right. I selected this open area of the park with a clear view of the northeast sky and a wooded area to my back to block some of the obnoxious moonlight. Temperatures at this time were a surprisingly chilly 52 degrees F, requiring me to wear a light jacket. But not a single bug bothered me! The meteor is seen streaking through the constellation Auriga in this image. Above Auriga is the constellation Perseus--the radiant of the meteor shower. Below right of Perseus is the Pleiades, and below that the constellation Taurus. At bottom center of the image, just above the tree line is the -3.98 magnitude planet Venus, and at bottom right is the partially obscured constellation Orion.

4:14 am. Meteor number two, just left of the planet Venus at bottom left.

4:30 am. Meteor number three, just above and left of Venus.

Composite image of all three meteor images.

Stacked image of all shots taken during this session. A total of 156 20-second exposures were used, starting at 3:43 am and ending at 4:36 am. The settings for each exposure was f/2.8, 200 ISO, 11mm focal length. Nikon D7200 DSLR camera.

Closeup of very top image. Multi-colored Perseid meteor streak in the constellation Auriga. 4:10 am.

Read more...

Revised Solar Eclipse Procedures, Revised Objectives

Continued research has caused me again to change my planned photography procedures for the total solar eclipse on August 21. For the partial eclipse phase, not a lot has changed from the last posting, except for these: It IS in fact possible to autofocus on the sun while the solar filter is attached. After autofocus is achieved by this method, I will switch to manual focus and further secure the lens with a small strip of electrician's tape. Bracketing will be the name of the game. The above Nikon D7200 DSLR image, captured handheld at 3:37 pm CDT, Friday, August 4, 2017, was part of a 7-stop bracket, set beforehand at 1/1000 second, f/5.6, 300mm focal length and 320 ISO. The best image of the seven (above) turned out to be a 1/1600 second shot, later enhanced in Adobe Lightroom 6. Note the sunspot at left.

As far as revised eclipse objectives are concerned, my new one may have been influenced a bit by some professionals out there who advocate a first time total solar eclipser to "forget the cameras and just experience it by eye." Duly noted, but to the sky photographer in me, that would be blasphemy! Well then, what about a compromise? Again, bracketing to the rescue. Just before totality occurs, the camera will be mounted on the tripod with only a settings change in shutter speed--now at 1/80 second. With the seven-stop bracketing available, a good capture of the sun's corona should be possible just after the show begins and the solar filter is removed. I will only have to concentrate on the sun being centered in the viewfinder for the opening moments. This hopefully will leave me with about 2 minutes worth of free and naked-eye enjoyment of this once-in-a-lifetime event!

Read more...

Solar Eclipse Photography Practice

Practice for the upcoming August 21 total solar eclipse. This session on Thursday, August 3, 2017 involved handheld captures and bracketing. My lens of choice for the event will be my Nikon AF Nikkor 70-300mm 1:4-5.6 G lens. Although not creating a particularly large image of the sun's disk, it will hopefully allow for a good view of its corona during totality. For capturing the partial eclipse phases, I will use my 62mm Seymour Solar Helios solar filter. This is a front threaded filter.

For the partial phases I will capture the sun with my Nikon D7200 DSLR camera handheld. This is because in my opinion it is not as critical to capture minute clarity during this time, and finding the sun in the sky is quicker. I have discovered that locating the sun at 300mm focal length is more difficult than one might think! My focusing procedure is as follows: I autofocus on a distant sky object, such as a cloud or aircraft (infinity setting is rarely accurate). I then switch to manual focus and further secure the lens with a 3-4 inch strip of electrician's tape. After this is done, I will thread on the solar filter and attach the lens hood (Nikon HB-26).

The composite image seen above is from today's five-stop bracketing sequence of the sun. In manual mode, I set the shutter speed at 1/800 second, f stop at 5.6 and ISO 320. From left-to-right, the shutter speeds created from bracketing are 1/3200 sec, 1/1600 sec, 1/800 sec, 1/400 sec, and 1/200 sec. The larger sun is an HDR-created image of the five. Note the sunspot at left of the sun's disk.

For the totality phase the camera will be mounted on the tripod, sans filter. I plan to use the same f stop and ISO, but will change the shutter speed to accommodate the low light. A remote cord will be used.

Read more...

July 19 Clayton County Iowa Severe Weather

An Enhanced Risk for severe weather for northeast Iowa was posted by the Storm Prediction Center on Wednesday, July 19, 2017. Sustained severe weather moved east from South Dakota in the morning into southern Minnesota and northern Iowa, reaching Clayton County by 5:50 pm. Before its arrival, I selected an open spotting location on Highway 13 at the top of a hill about one mile north of the town of Strawberry Point. Above, I await the approaching storm at 6:04 pm in this panoramic image facing northwest. Note its wind-driven "cake layered" appearance.

6:08 pm. The leading edge of the storm, now about 7 miles distant, has taken on a shelf cloud look.

6:11 pm. A dramatic capture of the leading edge of the shelf cloud in the NNE sky.

Also 6:11 pm. Turbulent leading edge of the shelf cloud in the SW sky. Storm movement was right-to-left in image.

Vertical capture of the same view a few seconds later. The leading edge of the shelf cloud has generated small and very brief funnels.

6:12 pm. The shelf cloud has created an sun-illuminated arch as it moves toward the back right of this panoramic image (southeast). Nikon D7200 DSLR camera.

Radar capture of the area for 6:05 pm. Note the red tornado-warned box in NE Clayton County.

Read more...

July 21 Johnson County Tornado Warning

Still located at the Interstate 380 rest area just south of Cedar Rapids, Iowa and just north of the Swisher exit, the severe storm cell in Johnson County on Friday, July 21, 2017 was progressing.
This image, captured at 4:46 pm CDT, shows an extensive shelf cloud stretching west from the intense center of the cell.

Meanwhile, toward the center of the cell one minute later, things were getting interesting. This image shows a lowering with an intense rain-wrapped area where I was sure a tornado might form.

4:48 pm. Panorama looking south toward Johnson County as seen from the rest area.

4:49 pm. Zoomed-in version of the image above this one. Note the turbulent low hanging clouds along the southern horizon in the background. This was captured right as, or just before a tornado warning was issued for Johnson County, with the towns of Kalona and Hills later being effected. Nikon D7200 DSLR camera.

4:50 pm. Radarscope Pro capture of the moment, showing my position (blue target) and the tornado-warned box in red.

Read more...

July 21 Generation Gap

While the atmosphere was generating this severe storm in Johnson County, Iowa on Friday, July 21, 2017, a large gap appeared between the wall cloud--located more to the east--and a shelf cloud--spread out to the west. Above is a panoramic view of the storm at 4:40 pm CDT, as seen from the Interstate 380 rest area just south of Cedar Rapids, Iowa and just north of the Swisher, Iowa exit. The gap exhibited a dynamic churning motion, sort of a battle between the rotating and the straight line areas of wind.

4:42 pm. A slightly closer panoramic view of the area, with the strong updraft area inside the gap more visually prominent.

4:43 pm. A vertical and closeup of the finely textured gap, with the wall cloud residing at lower left.

Also at 4:43 pm, with a wider field of view of the "battleground."

4:44 pm. Just below the gap area. Nikon D7200 DSLR video frame capture. With a ragged funnel and a lowering here, a tornado seemed imminent, but failed to happen. Tornado warnings were issued further south for the towns of Kalona and Hills in Johnson County less than ten minutes later.

Radar capture for 4:45 pm. My position at the I-380 rest area is indicated by the target icon, with the arrow pointing to the more intense area of the severe storm. The white circle indicates the approximate location of the gap.

Read more...

July 21 Storm: The Beat Goes On

More images of the Johnson County Iowa storm on Friday afternoon/evening, July 21, 2017.
Above, a classic wall cloud continued to wow me at 4:34 pm CDT. This image looks southwest from the rear of the Interstate 380 rest area, just south of Cedar Rapids and just north of the Swisher, Iowa exit.

4:36 pm. Resembling a tall-whipped ice cream cone, this vertical image captures the storm's aggressive updraft (top) and its wall cloud (bottom).

This video frame capture shows the turbulent top of the severe cell at 4:39 pm. Nikon D7200 DSLR camera.

Radar frame capture for 4:35 pm. The most intense area of the storm is indicated by the arrow, and my location at the rest area, the target icon. Storm movement was generally to the east.

Read more...