burst

Power of a RAW file

One of the examples I showed during our processing portion of our workshop in Apalachicola was a single frame snapped at sunrise.  As the sun was cresting the horizon I took one exposure for the sky, so naturally the foreground lost a lot of detail by doing this.

I was using my Sony A7R, which is a 36MP Full Frame Sensor.  I knew I could get away with pulling quite a bit out of the shadows due to the sensor recording all of that information at the point of capture.  To show all of the workshop participants what kind of power the sensor and RAW file had, I walked through a quick processing tutorial on that image.

Here is the RAW file straight out of the camera:

ISO 100, 27mm, F/16, 1/40th second

ISO 100, 27mm, F/16, 1/40th second

Now see how much detail I could get out of the shadows just using Adobe Lightroom?  I could've gotten a lot more even, but I this was as much as I really "wanted".

ISO 100, 27mm. F/16, 1/40th second

ISO 100, 27mm. F/16, 1/40th second

You can see how pretty much everything in the foreground came to life with just a few sliders in Lightroom.  Like I mentioned earlier, I could have pulled more data that this out of the shadows, but doing so really started to look very unnatural to me, so this is where I decided to stop.  Sometimes, I am still amazed at how much data is in the RAW files that come out of this Sony.

Sun stars...How? Why?

A question that came up recently was about how to obtain a sun star when your including the sun in your composition.  While the short answer is use a small aperture, like F/16-F/22, I wanted to attempt to explain why that helps...

The above photo was taken at DeSoto Falls near Mentone, AL at sunrise.  I shot this with a very small aperture, like mentioned.  This one was at an aperture of F/22.

How?

These are the short answers...Use a small aperture and this is much easier achieved at a wider angle.

Why?

This happens because of light "bending" around the aperture blades of your lens.  This is where knowing your lens comes in super handy!  How many "points" you obtain coming off of your sun star depends on how many aperture blades your lens has.  If your lens has an odd number of aperture blades, like 7 or 9, your lens will double that and you should end up with a 14 or 18 point star.  If your lens has an even number of aperture blades, like 6, then your lens will yield a star with the same number of points as you have aperture blades.  So a lens with 6 aperture blades will give you a star with 6 main points on your star...there are chances that those "points" may be split, but there will still be 6 main points.

The image above was taken with my Tamron 24-70mm F/2.8 Di VC USD Lens, which has 9 aperture blades.  If there was a full star there, and it wasn't partially blocked, you would see 18 points on that star.  For the record, I enlarged the image and I was able to count about 13 that were unobstructed.

Thanks to depth of field, using a smaller aperture allows you to pick up much sharper, well defined points of the star, which is why F/16-F/22 is usually recommended.

If you want a full sun star, then you would not want the sun obstructed, or diffracted, by anything.  However, these stars are typically much more interesting in compositions when the sun is diffracted by something like the horizon of the earth, a mountain, trees, etc.

Hearing that a small aperture creates a nice star burst, I would not suggest you try this at say, F/32.  The main reason I wouldn't suggest that is most lenses aren't at their very sharpest point at that small of an aperture (remember that a large depth of field will mean everything is in focus, not that everything will be at it's sharpest).  This, of course, is based on your lens.  The more experience you have with a particular lens, the more you will learn things like its' sharpest aperture...that comes with field time.