There’s no denying it – we’ve all deleted countless shots both off our camera and off our computers because they were just even to horrible to admit to publicly. And while filtering out the chaffe from the wheat is a good thing, if we don’t learn from our mistakes, we’ll continue to get chaff and never be able to make bread (take great pictures)! So, don’t just look at blurred photos and toss them instantly without thinking. Don’t immediately delete out of focus subject matter, and most importantly don’t blindly drag your less than stellar work to the trash bin.
So wait – does this mean to keep our bad pictures? For a short while – yes it does. You certainly are not going to go back and create photo galleries for clients with their mouth firmly clamped onto a forkful of food, but in seeing bad pictures and recognizing what makes them bad, helps you to avoid errors in the future. And to help illustrate what I am talking about, you’re going to see something here today that is a cardinal sin in photography – I am going to show you a terrible shot! Take a look at this:
So, why is this terrible? Well, it was taken from my recently built star tracker. As you may recall from the DIY video on YouTube, the whole purpose of a star tracker is to minimize star trails…to keep the stars bright and in one location as your camera moves relative to their position in the night sky. So, when I saw the above image, needless to say I was disappointed. But in seeing not only the blurred star, I also noticed that the star was much more blurred than it would have been from even being on a stationary tripod. This told me that the problem could be one of several things:
- There is a flaw in the design of my tracker, or…
- There is a flaw in the execution of the shot, or…
- There is a flaw in the design of the camera, or…
- There is a flaw in the design of the photographer!
So, back to the drawing board I went, hoping it wasn’t #4! What did I do wrong? Off to the web I went – first stop: Wikipedia on Barn Doors. As it turns out, I learned that while the barn door I built was the simplest in design, referred to more scientifically as a Haig Mount (characterized by a bolt or screw that rotates vertically as it pushes the one door up. Advances in the mathematics show that if you tilt the screw and have it push the door up at an angle, you are using the Isocoles method, which translates to less shift as your exposures get longer. Finally, the curved bolt mount minimizes shift even further. As the details explain at Wikipedia though, the shift only occurs in exposures as your shutter length increases past the 5 minute mark. Since I was doing a 30 second exposure, the design should not have been a factor. Other links off of Wikipeda pointed me to a several sites on how to build better barn doors, using a different method, but one note struck a chord with me:
“The double arm mount shown in the photograph uses a 6mm (M6) threaded rod to drive it.”
The more I thought about it, the threads on the bolt I used were awfully thick, so one revolution in a minute likely pushed the top door more than it should have gone, thus causing the significant star trail. The little jig in the line also told me I was not moving the screw smoothly and that I should probably motorize this if possible. Clearly the project is growing more detail-oriented, and mistakes have been made. But, as I (we) learn from mistakes, our chances of capturing better images only increases with time. As I make the modifications, I’ll report back with more details, but some additional points to consider that I learned through all my additional reading if you’re interested:
- Polar alignment is critical – this means you have to have some understanding of the stars and where they are in the sky (time to brush up on the astronomy class I took in college…)
- If you want to build a DIY kit – an average to intermediate grasp of math and formulas helps because your dimensions are dependent on one another for proper configuration (I am going back to check my cuts and drilling points on the first kit, but I am happy to know I have some spare parts in reserve…)
- Wider lenses are more forgiving on trails, and longer zooms are less forgiving – if you are just a hair off, that movement will be even more pronounced on a field of view that is narrow… (I was shooting on my crop sensor, with a t.4 TC and my 70-200 zoomed all the way in (448mm) – a pretty narrow field of view).
For today though, (and this holds true whether you are into astro photography, landscape, wildlife, portrait, event, or any genre of photography) the instructive point is to learn from your mistakes. As the old saying goes – those that don’t learn from the mistakes from history are doomed to repeat them. I had an economics professor in college say something very similar to the class once too: “I don’t care how many mistakes you make in this class – just don’t make the same one twice!”
So, look at your bad photos – find out why they did not come out well. Was it the camera? Was it the subject? Or was it the photographer? Learn from your mistakes so you don’t repeat them! Kind of an odd post for today, and for those that are not into astrophotography, I promise to return to some content tomorrow that has a wider interest base. But I figured that when I learn something, the whole point is to share that newfound knowledge with the reading and listening audience. On that note, how about the rest of the CB faithful? Anyone out there have any mistakes or goofs they learned from? Share your mistakes if you dare in the comments! (Or with me privately if you’d like to contribute, but remain anonymous – jason <AT> canonblogger <DOT> com.) Thanks for stopping in all – keep on shooting and we’ll see you back here again tomorrow! Happy shooting!