Venus Transit

Well, it happened.  The last transit of Venus until 2117.  The viewing weather locally was pretty awful:  all clouds and little sunshine.  My dad's telescope was out, but saw nothing.

I paired my 400mm Nikkor (the old AI-S f/5.6 IF-ED version of the lens; not anything newer) with the D7000 and the Hoya ND400 (9-stop) filter, and I managed to pull out two shots between the clouds:

5 June 2012 18:16 EDT

5 June 2012 18:19 EDT

While the results were relatively meager, it was a successful use of the filter, and I'm looking forward to seeing what else I can do with it in the future.  The weeks have been busy lately, and I'm hoping to get out to take more photos soon.  I have been continuing to work on my raw workflow, too.  More pictures after the jump.

The NL Filter is your friend

I'm not too familiar with Photoshop, never having used it.  I suspect that it has rather more advanced filtering than the Gimp, my usual pixel-editing program.  In any case, for those doing editing work that involves clean-up (as my latest moon shots have required), the NL filter is a huge win for you.  The link has the documentation.

Over-developed Attempts with TC-301

I've made my first attempts with the TC-301.  The results are a bit over-developed, but as a start it's probably not too bad:

400 (800) mm f/5.6 @ f/8(16), 1/100s, ISO 200

Upcoming Celestial Events

There's an annular eclipse coming up in May, and Venus will transit in front of the Sun in June.  The transit in particular is of some interest, since the planet will not make the transit again for over 100 years.  Hopefully I'll be dead when that happens.  While I didn't set out to do astrophotography when I bought my camera, I'm considering picking up a solar filter and a teleconverter (probably a TC-300 to mate to the 400mm—turning it into a 1200mm- f/11-equivalent lens on my d7000) to try to capture both events.  I'll probably do some tests on the Moon if I make the purchases.  I'm also considering extension tubes, which could have some interesting effects on the 400 as well, particularly in macro ranges.

On ND filters

For my birthday last year, I was gifted with an ND grad (.6, i.e., two stops) filter.  I haven't used it very much in regular shooting, but a recent trip out to a local tourist trap provided some opportunities to use it.  I've been trying to refine a raw workflow, but my hardware is limited and it has been a bit of a struggle to produce images in a timely fashion.

Neutral density filters are useful for a variety of scenes.  An ND filter reduces the light hitting the sensor by some amount.  This is helpful for scenes with a wide dynamic range (e.g., a sunset) or when additional motion blur is desired.  In the former case, the filters are usually graduated so that the horizon can be set properly:  above the grade, light is reduced; below the grade it is transmitted without change.  This is the sort of filter I have, but it serves in both capacities because it is large enough to fit over a 52mm lens without touching the grade.

Images with discussion following the jump.

More Moon Work

So I'm still getting started with the raw workflow.  The issues of noise and other artifacts come up pretty often when I'm working on the moon pictures, especially at 400mm.  The 70-300 seems like its not as sharp, but it also handles the noise a lot better.  I don't shoot with it anymore, so there's no definite side-by-side comparison.

I processed another photo today of the moon with RawTherapee, emphasizing better noise reduction (luminance, chrominance, and so on).  Here's the result:

400mm, 1/800s, f/11.0 @ ISO 200

For reference, here's the other processed image; it's a bit sharper, and the exposure compensation is obviously different:

The Moon, Again

With the full moon and a clear sky last night, I couldn't resist taking a few moments:

400mm @ f/11, 1/800s, ISO 200

In the raw processing, I added about 3.5 stops of exposure and did some denoising.  This lost a little definition, but the atmosphere was definitely getting in the way of a noiseless shot.  After the import, I applied very slight curves adjustment and an unsharp mask.

The 400 really is a swell lens.  I shot at f/11 to see if I could get a sharper image than I've gotten shooting at f/5.6, but it doesn't appear to have made much difference.  This isn't too surprising, since I'm shooting a crop sensor and holding pretty steady in the center of the imagine.

This was shot hand-held.

A Few Recent Shots

400mm @ f/5.6, 1/15s, ISO 3200

This one was all about seeing what kind of noise reduction I could get out of a raw image.  I balanced this on my car.  Shooting 400mm at 1/15s and getting a clear image is nearly impossible to do.  This was pointed somewhere in the direction of Orion.  Noise reduction in post did a lot to make this look decent.  Unfortunately my recent pictures of Jupiter and Venus did not come out as well.

400mm @ f/5.6, 1/500s, ISO 800

More evidence that it's hard to take clean pictures at such a long focal length, even with a short shutter.  The depth of field here is so thin that it's nearly impossible (for me, anyway) to get the subject in focus when working manually (as my lens is).  On the other hand, the 600mm-equivalent focal length is great for getting in tight for the little guys:  this one was maybe 40 feet away.

55mm @ f/5.6, 1/500s, ISO 400

The 55 micro doing what it does best:  being super sharp and getting to about 1:2.  The depth of field so close is razor thin, seen clearly in how only one of the antennae is in focus; I couldn't even get the whole head to fit properly.  This image endured some straightening in addition to the square crop.

55mm @ f/3.5,1/500,ISO400

55mm @ f/3.5,1/160,ISO400

The nice thing about the 55, though, is that it'll work well in other situations, too:  as a short tele on DX, it's got nice sharpness and subject isolation, even with the relatively slow max aperture of 3.5.  The macro ensures that bokeh is smooth in close focusing, even though the old f/3.5 AI-S model only has six aperture blades. Much of the recent Hopewell trip was shot with the 55.

55mm @ f/3.5, 1/80s, ISO 400

Typically you see this kind of visual effect in very fast lenses:  the 35 f/1.4 and 28 f/2 (and 24 f/2) AI-S lenses are well known for it.  I simulated the effect by letting the new sprouts dangle forward into the frame inside the minimal focus distance.  While it's probably not the best composition, it did make for an interesting effect and color play.  The geometry here is fun.

Vibrancy and Saturation

Thom Hogan posted a recent article on the difference between color saturation and vibrancy, and it's well worth the read for those interested in how to manage colors in post.  Most cameras have a "vivid" setting that allows users to dial up color saturation in camera, but often these settings blow out colors we'd rather leave alone.  Ken Rockwell is fond of VIVID++!!!BANGBANG!ONE!, but notes that this usually destroys skin tones, for example.

Color correction is a big subject about which I know comparatively little, but he mentions a significant issue when increasing color saturation:  linearity.  A heedless linear increase in color saturation across all spectra will lead to poor results.

While Photoshop has (I'm led to believe) a vibrancy control, the Gimp does not.  (There is a vibrancy plugin, but as far as I know it's not standard.)

A suitable method for increasing saturation in a non-linear fashion is to decompose the image into an appropriate color space and modify the saturation curve.  For the following example, I'll use an image from my shots at Hopewell Furnace.

Recent Trip

I recently went on a day-trip with some friends to shoot locally.  We had pondered doing some geocaching during a four- or five-hour trundle around the countryside but ended up spending most of our time at a historical furnace.  The day was mostly overcast, and I ended up shooting with a -1 or -2/3 exposure bias most of the time.  The 55 micro was on the camera most of the time thanks to its sharpness and contrast, but I had a few good shots with the 85 and 400 as well.

Developing Negatives Digitally

This past Christmas, my siblings gifted me a gently-used Nikkor 55mm f/3.5 AI Micro lens.  I have been wanting to fool around with a macro lens for awhile, but especially for the purpose of developing old negatives.  I visited Costa Rica in 1997 and Germany in 1999, back before I'd even thought about digital capture, and while I doubt I got much in the way of good pictures, digitizing the film seems like a fun project.

My parents also have some old slides (what a trip through the way-back machine that's been!) that I figured I could digitize as well.  My father was a photographer in his own right back in the day, and he lent me his lightbox to play around with.  I have to see if I can get his old bellows to work with the lens (that would be a minor coup), but if so, I should be able to make some pretty solid prints.

My experience with Walmart's digital scans is pretty poor.  They have a nice Fuji process for printing (which I prefer to Kodak's), but their scans are barely 1.5 megapixels and lack any sort of quality.  While I can and have doctored the images in the Gimp, it's really not nearly as good as you can produce with a suitable negative development workflow.