Josef “Jeff” Sipek

D750: A Year In Statistics

It has been a year since I got the D750 and I thought it would be fun to gather some statistics about the photos.

While I have used a total of 5 different lenses with the D750, only three of them got to see any serious use. The lenses are:

Nikon AF Nikkor 50mm f/1.8D
This is the lens I used for the first month. Old, cheap, but very good.
Nikon AF Nikkor 70-300mm f/4-5.6D ED
I got this lens many years ago for my D70. During the first month of D750 ownership, I couldn’t resist seeing what it would behave like on the D750. It was a disaster. This lens just doesn’t create a good enough image for the D750’s 24 megapixel sensor.
Nikon AF-S Nikkor 24-120mm f/4 ED VR
I used this lens when I test-drove the D750, so technically I didn’t take these with my camera. With that said, I’m including it because it makes some of the graphs look more interesting.
Nikon AF-S Nikkor 24-70mm f/2.8G ED
After a month of using the 50mm, I got this lens which became my walk around lens.
Nikon AF-S Nikkor 70-200mm f/2.8G ED VR II
Back in June, Nikon had a sale and that ended up being just good enough to convince me to spend more money on photography gear.

Now that we’ve covered what lenses I have used, let’s take a look at some graphs. First of all, the number of images taken with each lens:

Not very surprising. Since June, I have been taking with me either the 24-70mm, or 70-200mm, or both if the extra weight is not a bother. So it is no surprise that the vast majority of my photos have been taken with those two lenses. The 50mm is all about that first month when I had a new toy (the D750!) and so I dragged it everywhere. (And to be fair, the 50mm lens is so compact that it is really easy to drag it everywhere.) The 230 photos taken with the 70-300mm are all (failed) attempts at plane spotting photography.

First, let’s look at the breakdown by ISO (in 1/3 stop increments):

This is not a surprising graph at all. The D750’s base ISO is 100 and the maximum native ISO is 12800. It is therefore no surprise that most of the photos were taken at ISO 100.

I am a bit amused by the spikes at 200, 400, and 800. I know exactly why these happen—when I have to adjust the exposure by a large amount, I tend to scroll the wheels a multiple of three notches.

Outside of the range, there are a couple of photos (52) taken at ISO 50 (which Nikon calls “Lo 1”) to work around the lack of an ND filter. There is actually one other photo outside of the native ISO range that I did not plot at all—the one photo I took at ISO 51200 (“Hi 2”) as a test.

Now, let’s break the numbers down differently—by the aperture used (again in 1/3 stop increments):

I am actually surprised that so many of them are at f/2.8. I’m well aware that most lenses need to be stepped down a little for best image quality, but apparently I don’t do that a third of the time. It is for this kind of insight that I decided to make this blahg post.

Moving on to focal length. This is by far the least interesting graph.

You can clearly see 4 large spikes—at 24 mm, 50 mm, 70 mm, and 200 mm. All of those are because of focal length limits of the lenses. Removing any data points over 500 yields a slightly more readable graph:

It is interesting that the focal length that is embedded in the image doesn’t seem to be just any integer, but rather there appear to be “steps” in which it changes. The step also isn’t constant. For example, the 70-200mm lens seems to encode 5 mm steps above approximately 130 mm but 2-3 mm below it.

I realize this is a useless number given that we are dealing with nothing like a unimodal distribution, but I was curious what the mean focal length was. (I already know that the most common ones are 24 mm and 70 mm for the 24-70mm, and 70 mm and 200 mm for the 70-200mm lens.)

Lens Mean Focal Length Count
24-120    73.24138 87
24-70    46.72043 6485
50    50.00000 1020
70-200    151.69536 4438
70-300    227.82609 230

Keep in mind these numbers include the removed spikes.

Just eyeballing the shutter speed data, I think that it isn’t even worth plotting.

So, that’s it for this year. I found the (basic) statistics interesting enough, and I learned that I stay at f/2.8 a bit too much.

Septemberfest 2016 - Birds of Prey

This past weekend, the Dunstable Rural Land Trust had its annual Septemberfest event (yes, it ended up being in early October this year). Holly and I went to it armed with the cameras hoping to get some nice images of birds from the “Birds of Prey” program. We were not disappointed.

So far, I have managed to sift through only the bird photos. I still have to go through the other ones (e.g., the colorful autumn shots) and figure out which are the keepers. I set up a gallery which I’ll update with the non-bird photos in the near future.

Without further ado, here are the birds!

The peregrine falcon:

The screech owl:

The great horned owl:

The Harris’s hawk:

The red-tailed hawk:

The American kestrel:

The golden eagle:

This is only a fraction of the photos that are in the gallery, so make sure to check it out for more avian goodness.

Earth Day

For Earth Day, Holly and I went to the nearby Sherburne Nature Center for their Earth Day celebration. The three hour event included a walk through the woods there as well as a demonstration of some owls. We showed up a bit early, so we meandered in the woods for a bit on our own. I was armed with my D750 and the 24-70mm lens, and Holly sported the D70 with the 18-70mm kit lens at first but switched to the 70-300mm not too long after. While I did all the post-processing, some of the following photos are Holly’s. As always, there are more photos in the gallery.

While meandering, we found a large-ish Wikipedia article: garter snake—I’m guessing it was about 1m long.

After about an hour of roaming around, we joined the narrated nature walk. The guide, Mark Fraser, was quite good at spotting assorted nature that I was totally unaware of. For example, he took all of 15 seconds to find this (much smaller) garter snake.

The nature walk was followed by the owl demonstration by Eyes on Owls. As you can see, the owl demonstration attracted a lot of kids.

After a brief intro to owls, six different owl types got shown. Of the six, I post-processed photos of four. (We got photos of the remaining two as well, but none of them struck me as interesting enough to post-process.) All of the owls they brought suffered from some sort of injury that made them unable to survive in the wild.

The screech owls:

Screech Owls

The barn owl:

Barn Owl

Barn Owl

The spectacled owl:

Spectacled Owl

Spectacled Owl

The snowy owl:

Snowy Owl

I wished I had a more telephoto lens than the 24-70mm, but thankfully the owl demonstration was pretty close to me—and the 24MP on the D750 let me crop quite a bit. At the same time, it is my understanding that for birding one wants the longest lens possible anyway. I’ve even heard that birders prefer DX camera bodies because of the crop factor. I think I understand them, but I’ll just stick to photographing mostly non-bird subjects and keep the FX sensor. I guess the world’s birds will have to be photographed by someone else. :)

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