Monday, September 18, 2017

How to Use a Camera's Histogram

The histogram is a new tool for photographers when working with digital imagery. They can be confusing and intimidating when first encountered, but once explained they are easy to understand and very useful. In this series of videos, I show what they are and how to use them in a variety of different situations. Hope they help!

How to read a camera's histogram

How to get a perfect exposure using the histogram

How to reduce noise using the histogram

How to isolate a subject on white using the histogram

How to use histograms in Photoshop

Monday, September 4, 2017

Topics for the Beginner Photographer

Recently I published several videos for beginner photographers. Hope they help.

The Absolute Beginner's Guide to Removable Lens Cameras

How to Take Your First Picture

10 Tips for Better Photos

Thursday, July 24, 2014

After Effects Numbers-To-Letters Transition Tutorial


Tutorial for transitioning numbers to text in After Effects. This is a mash-up of two techniques I learned from Mikey at the After Effects Tutorials with Mikey channel.

His videos presenting these techniques are:
Text Link After Effects Quick Tip
Random numbers transition to text


In this tutorial, I'm going to show how I did this text transition, but first a little background.

As of late, I have been doing more video work than still photography and as such have been working in less in Photoshop and more in After Effects. To learn the video side of things, I've subscribed to a number of different YouTube channels that do a lot of After Effects and Premiere Pro tutorials.

One of these channels is "After Effects with Mikey." He does a lot of great stuff, short, sweet and to the point, and I've learned quite a bit from him. Definitely check him out if you're looking for After Effects tutorials.

Recently he did a tutorial on transitioning random numbers to text, the effect I showed at the start. I learned about the Character Offset animator at the beginning but about half way through he took a left turn when I expected a right. I followed what he did ok and he ended up at his destination just fine, but, given a previous tutorial he'd done a week or so earlier, I thought it was sort of the long way around.

So, in this tutorial, I'm going to combine two techniques he showed in a way that I think makes achieving the effect easier.

If you want to see his tutorials first, pause this video and click the links here or in the description below.

Now, let's dive into After Effects.

First, we want to create a new composition. The properties don't really matter, you can use whatever you want, but you do want to remember your frame rate. That's important for later. Go ahead and create a new composition.

Now we need to create a new text layer and we want to put in here the text we want to end with. In my case I'll use "Hooked on Light." And this effect works best, if you use a fixed width font. So in this case I'm using Courier New.

Then we want to add another text layer and this time we want to put in random numbers, as many numbers as you have characters in the first text layer. Because the numbers are going to cover up the text so we want the same number there.

Now we want the text to follow the numbers wherever it goes. We want them to be sitting on top of each other. So I'm going to select both layers and hit "P" to bring up the position property. Then I'm going to alt-click on the position property for the text and pick whip that to the position of the numbers. Now if we look at that, the numbers and letters are in the same location. We can see that if we move the numbers, the letters go with it. Cool.

So the next thing we want to do is cause the numbers to change as we move through things.
We're going to select a "Character offset" animator and we're going to alt-click on the Character Offset line. And we're going to type in "time" star and your frame rate. In this case it's 24.

Now as we scrub through the time-line, we can see the numbers changing for us.

But we can see the text is sitting on top of the numbers and we don't want that. So now we want to fix that. And we're going to do that by creating an opacity animator.

And we want to first of all click on the layer to create a new animator. If we don't do that, it will create the animator, the new animator inside this animator, which isn't what we want. So we want to click on the layer there and then create another opacity animator. And we can see it creates an "Animator 2" now. That's what we want.

So we set the opacity here to zero and our numbers will disappear. Then we can go into the range selector, advanced, and we want to change "percentage" to "indexed" and smoothness to 0.

And now we want to set our Start to be the same number as whatever is in End. In this case it's 15. Yours will vary depending on how many characters you have in your text. And now we want to keyframe this where we want the numbers to begin dropping off. So in this case we want to go in about 2 seconds and I'm going to keyframe that. And then we go to where we want the numbers to completely drop off, where all the text should be visible. And then we set the Start keyframe to 0.

So now as we scrub through here we should see our numbers changing and we should see the numbers showing back up on top of the text.

So now I'm going to close this and then hit "U" to see only the items that have keyframes on them.

And then I'm going to scroll down the "Hooked on light" to open that guy up and then I'm going to add another character animator. Because now what we want to do is change the opacity of the characters to be the exact opposite of the numbers. So when the numbers are visible the characters aren't and when the characters are visible the numbers aren't.

So we're going to add another opacity animator to the characters. And we want to do the same thing with its range selector. Advanced. And set the - change "percentage" to "indexed" and smoothness to zero. And we want to set its opacity to zero.

But now we're going to do something a little bit different.

Now we're going to - instead of setting the Start like we did on the numbers - we're going to alt-click on the End - alt-click the stopwatch for the End - and we're going to pick-whip the End of this to the Start of the range selector for the numbers.

And what this will do is it will cause the ending value on the range selector for the opacity of the text to be exactly the same as the Start.

And now, if everything works properly, if we scrub to the beginning we should see nothing but numbers and then when we get to the first keyframe we should see the letters start to appear and as we move through the letters continue to appear as the numbers drop off.

And that's exactly what we wanted.

Now if we wanted to change, say the length of this time, all we need to do is change the keyframes right here in the Start. If we want to make the effect longer we can do that and everything woks out just fine for us. We could easy-ease those or whatever we want to do. And the End for the text will match up exactly with the numbers. It makes it very simple to reveal that text as the numbers disappear.

Well, that's pretty much it for this tutorial. Hope you found it useful. Catch you next time.

Friday, January 3, 2014

How to work with a Graflex RB Series B camera

Last year I wrote an article about my great-grandfather's Graflex RB Series B that I'd acquired from my Dad. Recently I posted two videos on my House of Hacks site.

The first is about cleaning the camera and getting it ready for making images.

The second covers loading film, setting exposure, taking pictures and the results from the first roll of film.

I hope you find these interesting.

Monday, December 9, 2013

How to hack a C-mount lens onto a Canon 5D

The other day I pulled an old industrial video camera with a lens on it out of the trash can. It was a beautifully built bit of kit and the trash can seemed the wrong place for it, even if it is so old as to be mostly worthless. The camera requires some specialty support hardware and doesn't do anything by itself. But I wondered if the lens might be interesting to work with.

I pulled the lens off; if simply had a screw mount. I also removed the lens from my 5D, held the video camera's lens up to the camera and did a bit of lens whacking. This was the result of playing around making images of my computer's login screen.

It has the smeary imperfections typical of a lens whacked image. However the odd color shifts in the center caught my eye. I wondered what cased them so I zoomed in to 100% and saw the following.

The individual red, green and blue dots in the image above are the sub-pixels that make up a pixel on the monitor. That's pretty cool. This lens has some potential for macro shots. So, I decided to make something a bit easier to work with than just holding the lens in front of the camera body by hand.

I had an extra body cap on hand that I'd purchased just for experimentation such as this. I pulled it out and drilled a hole just large enough for the threaded part of the lens to slip into.

I then attached the lens to the body cap.

I didn't want to make this a permanent mount in case I wanted to use the lens in some other configuration. So, a couple dabs of hot glue later and the two pieces were securely attached but fairly easy to pull apart in the future if I so desire.

Once the glue set, I put the cap/lens assembly on the camera and pointed it at my 24-105 that normally resides on the camera.

The images aren't perfect by any means, but they do have an interesting, dreamy quality to them with all the distortion around the edges. And the depth of field on the area that is in focus is incredibly shallow, like any macro situations. Notice how the yellow "Macro" is sharp in the top image and the red "50 35 24" are blurry. And then compare this to the bottom image where the focus is exactly reversed. I doubt there's 2mm between those two items, so the depth of field is obviously less than that.

The reason this lens acts like a macro lens is because c-mount lenses are designed to be very close to the sensor. Canon EOS bodies have a relatively large distance between the sensor and the lens mount. Because of these two things, a c-mount lens on an EOS body is sort of like having an extension tube or bellows attached to a normal lens.

Finally, here's an image of my computer's screen with the lens mounted on the body cap.

It's not really much different than the one that I took holding the lens by hand. Although the pixels aren't quite so washed out.

In this 100% crop of the grey line seen in the image above, the sub-pixels really stand out.

Next, I need to get some micro-adjusting slides and play around with some focus stacking.

Tuesday, December 11, 2012

High-speed event photography follow-up

This is just a quick post to say "Thanks" to everyone who came out tonight and to Jeremy Hall and Pete Stott for asking me to demonstrate how to capture shots of apples splashing and balloons popping. I had a great time and enjoyed sharing.

Here are the slides for anyone interested.

If you have any questions, feel free to post a comment below and I'll answer them to the best of my ability.

Update: Here's the eBay store that sells the wireless triggers I use: Gadget Infinity. Note, they are cheap. I haven't had too many problems with them, but some people have. For hobbyist use, I find them acceptable. If you're a pro, you'll probably want to go with something better.

Saturday, December 8, 2012

High-speed event photography presentation

I'm excited to give a talk on doing high-speed photography. This Tuesday, at the Utah County Studio Co-op led by my friend Jeremy Hall, I'll be showing the light and sound triggers I built a couple years ago. I'll go over how to setup and use them to consistently get shots that, without them, are pretty hard to capture.

It's basically similar material to a talk I gave a couple years ago at Photocamp Utah 2010. The video from that presentation is still available on Ustream and I wrote about it in a previous blog article.

If you're in the Utah County area on Tuesday night feel free to come out. The event is free and open to all. More information can be found on Facebook.

Tuesday, October 30, 2012

Treasures from Time: Polaroid SK-70 Land

The seventh and last of the cameras I brought back from my Dad's was another one that caught my wife's eye: the SX-70 Land camera by Polaroid. Manufactured between 1972 and 1981, this model with chrome and leather trim was sold to higher end markets.

This model has a number of interesting things. First, its form factor. It collapses down into a relatively thin package and pops up easily (once you figure out the technique), ready to make pictures. Second, due to the folding and the fact that it's a SLR, the light path has to go through some odd shaped lenses in order to provide a proper image to both the view finder and film. Next, the disposable flash bars had logic circuits in them to determine which bulbs were used and which one to flash next. Finally, the film pack included a 6-volt battery to power both camera and flash. This ensured power was always available whenever there was film in it.

Later variations of this design introduced in the mid-70's allowed the price to drop, being made out of cheaper materials and with more features. Film chemistry was improved over the life of the product and by the late 70's, this format was the top selling film in the United States.

Open Source Hardware is an interesting movement to watch today. Sort of like Open Source Software groups that publish all their source code, there are companies that publish all the source documents for making their products. The idea is to allow more innovation, providing a means for customers to easily understand and modify their technology. Polaroid, while not opening up to this degree, was a fore-runner of this concept by selling two kits for hobbyists to incorporate their technology. One was their sonar kit for measuring distance that they developed for the OneShot camera, a descendant of the one pictured above. The other kit allowed people to use the flat, high-current 6-volt battery in their own projects.

That's it for this series. If you want to see other articles about the cameras I recently acquired, the introduction to this series has an index.

Monday, October 29, 2012

Treasures from Time: Canon T50

This Canon T50 caught my wife's eye, probably because she has an AE-1. The T50 has an interesting mix of features. It was designed as an inexpensive, entry level 35mm SLR and was the first of the T series, replacing the previous A series SLRs. Because of its position as a beginners camera, automatic is the only exposure control mode. It has auto-loading and a motor advance, allowing 1.4 frames per second. All the electronics are controlled by two AA batteries. In contrast to all this automation, the focus and rewind are manual.

The T50 accepts FD mount lenses, as was standard for Canon when this model was made between 1983 and 1989. This allowed an impressive array of glass options from a 7.5mm fisheye to a 600-830mm zoom.

Canon introduced a new shutter with this model. All their previous SLRs had horizontal sliding cloth shutters. The T50 pioneered the vertical sliding metal shutters that are still used in their current SLRs. This allowed sync speeds higher than the 1/60th second limit imposed by the old technology.

The introduction to this series has an index of all the cameras I recently acquired.

Thursday, October 25, 2012

Treasures from Time: Kodak Pony II

As solid and advanced as the Retina IIc was yesterday, the Pony II is light and basic today. Shown above with an optional flash attached, this camera was manufactured between 1957 and 1962. It has a bakelite body with a simple viewfinder and takes 35mm film.

Focus is set by estimating the distance to the subject and dialing in that value on the dial around the lens. The lens is marked as 44mm at f/3.9 but the aperture control ring is indexed with exposure values, not f/stops. An EV of 9 is wide open and 15 closes the four bladed diaphragm to its smallest opening, which looks to be about f/22.

There is only a single shutter speed. I found a chart online that correlates exposure values/ISO to f/stops/shutter speeds. If I'm interpreting the chart correctly, I think the shutter speed is probably 1/30th or 1/60th of a second.

This is a really basic camera which made a perfect gift when I received it around 2nd grade. That's right. This is my first camera. I thought it had been lost or given away in the moves growing up, but Dad had it stored away somewhere and here it was, all ready for me to pick up again and start making pictures. It's light and plastic, but simple. And that means there's not really much to go wrong with it. It seems to work as well now as it did when I first got it, more than a couple decades ago.

The introduction to this series has an index of all the cameras I recently acquired.