Camera/Lens Testing Update

Pictures Taken: July 10, 2018

If you read through my previous blog post on camera and lens testing you are a hardy soul – that was not a short post – this follow up is for you. If you got through the first 50 or so words and thought “you have GOT to be kidding me” then you may want to skim over this as well.

The short version of the previous post was that I did not get the stellar results I had expected when taking pictures with my Sony A7R3 and Sony 24-105mm lens. After doing some research I came up with a test plan to see what would work better; I primarily used Aperture Priority with different focus area and focus modes – this is because I was following Mark Galer’s YouTube video called  Camera Settings for Shooting Action – Sony Alpha A7RIII and A7III  .

Early in the morning northbound trains rolled through the Ridgefield Wildlife Refuge about every 15 minutes. Here is a representative sample of these pictures.


When you look closely – try clicking the image to get a bigger view – the numbers and lettering are not as crisp as I was working for. The aperture size of 8 is the maximum to ensure Phase Detect Auto Focus (PDAF) which is the super fast focus mode for moving shots. I couldn’t tell if the blurriness was a factor of the shutter speed or low-ish f-stop; maybe the focal point was far enough way from the lettering and numbering to blur them.

Aperture Priority. 1/200 sec; f/8; ISO 200; Focal Length 48mm

I also tried a couple with Shutter Priority.

Shutter Priority. 1/800sec; f4.5; ISO 100

Much better here. The 1/800 second speed is 4 times faster than the first shot; even though the f-stop was a measly 4.5 things were still in focus. Conclusion: even though trains are not speeding through this spot, they are too fast for 1/200 second.

Aperture Priority. 1/500; f/6.3; ISO 100. Focal Length 41mm

I can’t explain why this picture uses a speed of 1/500 second with a wider aperture than the first sample even though it seems brighter. Regardless, 1/500 second improves the focus of the numbers and letters. Here are two closeups of the BNSF trains showing the small lettering that appears on the black rim at the front of the train; between the wheel set and the yellow/black stripes of the herald; and just behind the grab bar.

First, from the picture taken at 1/200 second.

20180710 Trains Focus Testing_A7R1519

You can barely make out the “ET44C4” model number.

Then the picture taken at 1/500 second.

20180710 Trains Focus Testing_A7R1614-2


The model number “ES44C4” is much clearer.

I couldn’t see on this on the small view finder but I knew that I needed to get more speed and tighter f-stop. Before I could do more testing some BNSF physical plant employees came out to put a couple of high railers on the track for some inspection. I didn’t want to be in their way so I headed south. I found a nice country road to get back to Vancouver so I wouldn’t have to hassle with I5.

As I was driving I pondered the question and decided to stop by the Amtrak depot in Vancouver just next to the Columbia River. The bridge was closed to rail traffic so the BNSF southbound I caught was slowing to a stop. Even though I would go past the PDAF limit of f/8 I pushed the f-stop to 13 to find out if contrast auto focus would work.

20180710 Trains Focus Testing_A7R1638-Edit
Aperture Priority. 1/200 sec f/13; ISO 400. Focal Length 43mm

The number boards were clear and at f/13 lettering on the two leading locomotives were in focus. 1/200 wasn’t good for trains at track speeds; but fine for those coming to a stop.

My last sample of the day is from another Amtrak Cascades heading north; again, coming to a stop at the station.

20180710 Trains Focus Testing_A7R1722-Edit
Aperture Priority. 1/320; f/16; ISO 800. Focal Length: 80mm

Again; pretty sharp and 1/320 second is fine for the slow movers. Contrast Auto Focus will work for slow speeds, it remains to be seen if it will be okay for faster moving trains.

When I got home I imported the pictures to LightRoom where I could get a better look at them. The overall lesson I took away is I want higher frame rate than I can get in Aperture Priority even with the settings Mark Galer recommended. And I can see how shooting trains is different from soccer players or running dogs. Trains are much longer and wider than people and animals (no duh!). So, what works for small objects may not work from huge subjects like trains. And the trains may be moving much faster than I think; their size may make it seem they are going slower than they are.

I came away with some new test cases.

  1. In order to force the camera to speed up the shutter and raise the ISO to compensate, pick a high value for the ISO Auto Min SS setting. I was using “Faster”. I didn’t need to take train pictures for this. I practiced at home and it didn’t work for me as I had hoped.
  2. Use Shutter Priority Mode as I did with the first Amtrak Cascades. Start with 1/500 second and work from there.
  3. Maybe I just need to bite the bullet and go to Manual Mode. push up the shutter and narrow the focus letting the camera adjust the ISO. Playing with my camera for all of 5 minutes indicates this should work.
    • Have samples of f-stops <= 8 and > 8 to compare PDAF with Contrast Auto Focus.
  4. Use a light meter to dial in the settings. I sure don’t want to spend $200 – $500 for a light meter. I found the well-reviewed Pocket Light Meter app for iOS. After watching a couple of YouTube videos I think I can get this to help.

I used the GoodNotes iOS app to keep track of my test cases. I tried to use 1 page per train but at the end I slapped a bunch on one page. Here is a sample from my GoodNotes notebook. I added the green notes in the evening after working with the images

Camera Settings - Trains

Um, yeah; there are 7 pages of this.

I’ve looked at enough trains for a couple of weeks – maybe. But I have my test plan ready to go.

Thanks for following along.

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