97% Totality.

The top of G-deck turned out to be a good decision. There were a few other people there, but nothing like the crowds in Woodruff park (where I understand fights broke out over viewing equipment.)

I used a regular photographic tripod, which is decidedly sup-optimal for astronomy, but good enough for this purpose.

You can see how the shadow appears to roll over the sun in the sequence below.

Ready for the eclipse.

I ordered a solar filter for my long lense. It looks something like a very fragile and expensive piece of tinfoil, but works.

Even with that filter, getting the exposure correct can be a bugger. I ended up in manual mode 1/4000 s f29 iso2000.  The featured image shows the results, and, yes, those dots in the middle of the sun are sunspots. So we’re ready to go.  I’ll probably play around a bit with the film speed to reduce noise, but this is decent enough to work.  I’ll use a tripod tomorrow and be at the top of G-deck.

 

If you don’t adjust the exposure, the sun is completely washed out. Not at all what you want.

 

Long term review of the Opteka 500mm lens

About a year ago i purchased one of these lenses to take pictures of wildlife. opteka

I now have enough experience to write a review.

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turkey

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Good points:

  • Inexpensive. $140 on Amazon. A “real” Nikon lens can run into the thousands.
  • Works. It does what it says. It will bring things into close focus. Including things you don’t want to get too close to.
  • Small, light and maneuverable A conventional telephoto lens is much longer and heavier.
  • Close focus You can focus on surprisingly close objects. This makes it great for taking pictures of things that don’t appreciate humans getting up close and personal.

Bad points:

  • Weakly coupled to the camera. Everything is manual, including exposure.
  • No autofocus. This limits its use in rapidly changing situations. Following a moving bird for example.
  • Paper-thin focus. Be prepared to take several photos to get the focus right
  • Infinity is not set at infinity on the lens. Don’t assume the stars are in focus.
  • The 2x extender leads to barrel distortions.

I generally use it with a fast shutter exposure (1/4000 s) to avoid blur and then control the exposure with the camera’s “film speed” setting. In bright light that’s about 2000ASA. In dim light, you may have to play around.

It’s also critical to make sure that the T-mount is firmly screwed into the lens. If it comes loose you won’t be able to focus.
This picture shows what I mean by paper thin focus:
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Note that I’ve focused on one wing of the butterfly and the other wing is completely out of focus.

This picture of an alligator and heron show the same effect at a longer distance.
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It should look like this:
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It can be an advantage to have a thin focus. The bird is clear and the reeds have disappeared.
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It’s great for taking pictures of things that aren’t moving too quickly, like this female cardinal.
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And you can get some great effects:
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In summary, you get what you pay for. It works. There are several things that could be better, but you have to fork over the cash. I wouldn’t use it for rapidly changing things like sports or moving creatures. But if you have the time to focus and remember to take several shots, it’s a great little lens.