Tag Archive for 'diy'

DIY nodal slide: Perfect panoramas

I remember having to do a panorama in a high school photography class. Mine was of a tree line across a lake shot with a 50mm lens on my old Pentax ME Super. It looked ok. Most things lined up.

For fun, I tried another one. On the second one, the subject was much closer. When I started to line up the images, I realized it just wasn’t going to happen. Nothing lined up. At the time, I didn’t know why. Now I do.

Two words. Nodal point. Essentially, this is the point where the image inverts in the lens.

When doing a panorama, many people will try to put their camera on a tripod using the threaded mount on the bottom of the camera body. Unfortunately, that is not under the nodal point and will cause distortion between images and not allow perfect alignment. Perfect alignment comes from the camera’s rotational point happening directly below the nodal point of the lens.

For example, I used the mount on the bottom of my camera months ago while doing a panorama inside of a church. Most things lined up but some of the pew backs did not. It is especially noticeable on the back few pews on the left.

The interior of the new St. Anne Catholic Church is seen in this photo illustration showing approximately a 180-degree view. The image was composed from 24 separate photos. (C-T photo illustration Max Gersh) ©2010

The interior of the new St. Anne Catholic Church is seen in this photo illustration showing approximately a 180-degree view. The image was composed from 24 separate photos. (C-T photo illustration Max Gersh) ©2010

What the camera companies would like is for you to buy one of their multi-hundred dollar panoramic tripod heads. But if you’re like me and know what lens you will be using and want to save a ton of money, it is pretty easy to build one on the super cheap.

I started out by getting a piece of 1/8″ aluminum. I had this already but you can find it at any hardware store. A long rail of it is about $10. I did buy a few bolts and nuts to tighten things down (total of less than $1.50). I made sure every piece of hardware was 1/4″-20, the same thread as a standard camera mount.

I centered and drilled a 1/4″ hole at one end of the aluminum plate. Then I mounted my camera to it with one of the bolts I bought.

There are plenty of tests online to find your nodal point. I did pretty much the same thing as everyone else. I set up two objects in a direct line about a meter apart. The camera is straight in line with them as well. As you pan, the items will stay in line if the nodal point is correct. If not, the objects wont appear to be aligned unless you are looking straight on. This website has visuals of how it looks when the slide is correct, too far forward and too far backwards.

**UPDATE** I’ve been asked how I had the plate attached to the tripod to find the nodal point before I had any holes drilled for attachment. I simply used a spring clamp similar to this one. I would slide the plate and clamp it in place and do the panning test. I then would adjust and re-clamp and the do it again and again until I got it just right.

When I found the right point, I made a mark on the plate and drilled a hole there.

I put the tripod screw through that hole and used a hex nut to lock it down. Then, used a bolt and attached the camera.

I was building this for my Canon 1D Mark II with the 24-70 f/2.8 L lens zoomed at 24mm. If you’re trying to make this for the same setup, the center of the two holes on the slide are about 5.5″ apart.

Now, if you have a drill press or other fancy tools, you could actually make this a “slide” so you could adjust it on the fly for other focal lengths. If I wanted to do another focal length, I’d have to do the alignment test again and drill a new hole.

This is the DIY nodal point slide on the floor with the camera hole and tripod hole drilled. I marked which was which to avoid any confusion in the field. ©2010

This is the DIY nodal point slide on the floor with the camera hole and tripod hole drilled. I marked which was which and added an arrow to show the direction of the lens to avoid any confusion in the field. ©2010

Here is what my camera looks like on the rig.

My Canon EOS 1D Mark II with 24-70 f/2.8 L lens on a DIY nodal point slide to acheive accurate panoramas. ©2010

My Canon EOS 1D Mark II with 24-70 f/2.8 L lens on a DIY nodal point slide to achieve accurate panoramas. ©2010

Having the urge to do an immediate test, I ran outside of my apartment and took a quick panorama of the building.

A quick test panorama of my apartment building using my DIY nodal slide. This panorama is composed of 14 images. ©2010

A quick test panorama of my apartment building using my DIY nodal slide. This panorama is composed of 14 images. ©2010

Notice how all of the lines in the sidewalk and building line up perfectly. Also notice my lovely shadow.

If you try this on your own, keep in mind that these panoramas are cropped to cut out the dead space. Dead space happens around the edges on all panoramas in the gaps where you don’t photograph. Here is the above panorama of my apartment with the dead space left in.

A quick test panorama of my apartment building with the dead space left in. This panorama is composed of 14 images. ©2010

A quick test panorama of my apartment building with the dead space left in. This panorama is composed of 14 images. ©2010

After determining that my nodal slide was a success, I headed out to Memorial Park in New Castle, IN to make some more scenic panoramas.

One I did while out there was of my car. It has many things that have to line up. I figured that would be another good test to make sure everything lined up.

A panorama of my Subaru Forester in Memorial park. This was shot on my DIY nodal slide and consists of 18 images. ©2010

A panorama of my Subaru Forester in Memorial park. This was shot on my DIY nodal slide and consists of 18 images. ©2010

All of the lines matched up perfectly. It lined up so perfectly that you can’t really tell how close I was to the car while shooting. I couldn’t fit the entire car in a single frame with a 24mm lens. Just keep in mind that it took 18 images to compose the entire scene.

I then turned to the large pond. I walked down into a muddy area where it appeared the water had receded. To put this to the true test, I did a 360 degree panorama. Composed from 55 separate images, the full resolution of this image is unreal.

A 360 degree view in Memorial Park made from 55 separate images. Shot on my DIY nodal slide. ©2010

A 360 degree view in Memorial Park made from 55 separate images. Shot on my DIY nodal slide. ©2010

With the same set of images, I decided to see if I could form it into what is commonly known as a “wee planet” through a process called stereographic projection. Here is how it turned out.

A stereographic projection (wee planet) at Memorial Park. Shot on my DIY nodal slide and consists of 55 separate images. ©2010

A stereographic projection (wee planet) at Memorial Park. Shot on my DIY nodal slide and consists of 55 separate images. ©2010

I’d say $1.50 well spent and good use of some scrap metal.

My DIY beauty dish works like a charm

I got the chance to test my DIY beauty dish this morning. It worked like a charm!

I once again had my friend Gavin Culbertson stand in for a few quick portraits.

Gavin Culbertson lit by my DIY beauty dish

Gavin Culbertson lit by my DIY beauty dish.

He was standing in the shadow with a sun-lit wall behind him. This picture could be improved with a back light but I only have one Speedlight, a Canon 550EX.

I love the circular highlight that shows up in the eyes of the subject.

Gavin Culbertson lit by my DIY beauty dish with circular highlights.

Gavin Culbertson lit by my DIY beauty dish with circular highlights.

I will need to play with it more but it certainly gives off a nice quality of light. Not bad for a $20 DIY light modifier.

DIY Beauty dish

Ever since I discovered what a beauty dish was, I’ve wanted one. The problem is that I don’t have any strobes to use one on. My lighting is limited to a single Canon Speedlight (shoe mounted flash).

How could I produce the look of a beauty dish with my one Speedlight?

Simple. Build a beauty dish to fit.

I’m not the most handy of the handymen. Therefore, instead of designing the dish on my own, I Googled other peoples designs and copied it. I ended up using the one I found on David Tejada’s blog. His looks better (and probably works better too but that is yet to be determined) but I gave it a good effort.

To get most of the parts, I visited Home Depot. The main “dish” is a plastic terracotta planter. I wanted to find a relatively shallow one that was 14″ across but they didn’t have any that size. I ended up getting a deeper one that is about 12″ across.

Next, I headed over to the gutter section. I was looking for what is called a drop out or outlet (I think). While David used a metal one, the only one that fit my Canon 550EX was a plastic one. It doesn’t really make much difference. If you are planning on doing this, bring your Speedlight with you to check the fit.

I then headed to the paint section. I bough a can of flat black spray paint and a can of glossy white spray paint. I figured the gloss might help the light reflect. Maybe not.

After leaving Home Depot, I went to the auto parts store and got a 3 3/4″ blind spot mirror.

When I got home, I began building. I traced the outline of the gutter outlet onto the bottom of the dish. I used a Dremel to cut it out because I could. I imagine a sharp knife would work just as well.

I then also cut the same shape out of the bottom of a CD spool. A little bit of hot glue later, and the dish, the bottom of the CD spool and the gutter outlet were one.

I then spray painted the inside of the dish white and the outside black. I didn’t want an orange dish.

I glued a CD to the inside top of the CD spool. On top of that, I placed that blind spot mirror.

The light will be firing through the back of the dish, which is also firing into the bottom of the CD spool. The light shoots straight at the mirror which spreads it back around the dish which in turn lights the subject.

The beauty dish as seen from the front.

The beauty dish as seen from the front.

A rear view showing the mount for the Speedlight and also the depth of the dish.

A rear view showing the mount for the Speedlight and also the depth of the dish.

The interior of the dish with the reflector off and set to the side.

The interior of the dish with the reflector off and set to the side.

I haven’t had an opportunity to test it on a person yet. The one thing I am concerned about is the direction of the light. This is what I would describe as a “shotgun beauty dish.” Its depth makes it a directional light modifier. I am concerned that it wont wrap a subject with light as beauty dishes are known to do.

Just from popping off a few test frames, I have noticed that I do lose about two stops of light.

Hopefully this weekend I will have an opportunity to further test it and see if this is something worth keeping. As soon as I find a wider and shallower planter, I will probably build another one.

This entire build cost me just over $20 but I already had a CD spool.




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