Ever wonder why large format photographers go under a dark cloth to look at the back of their cameras? It's mostly just to look super cool. However, a secondary benefit is that it makes everything dark so we can see the ground glass on the back of the camera. This "screen" is how images are composed, but it's not as straightforward as it sounds. For one thing, the image is reversed and upside down.
Above, on the left is how the image appears on the back of the camera. On the right is what the scene looks like in real life. You can see how composing an image can be a bit of a challenge. With a bit of practice, however, the image orientation becomes less of an obstacle. In fact, you would be surprised how quickly you adapt to composing this way; there are even some cases when I consider this method of composing superior. For example, I tend to notice distracting elements on the edges of the composition more when the image is oriented this way .
A bigger obstacle to composing comes from the ground glass itself. It is often dark...very, very dark. Several things can affect this: the scene you are photographing, the lens you are using, and the quality of the screen itself. Dark scenes can often be difficult or even impossible to compose depending on just how dark it is. This makes sunrise shots especially challenging as you are often composing in darkness and waiting for the light. The lens being used also plays a significant role. While composing, the lens is left wide open to let in as much light as possible. Faster lenses are preferable as they are brighter, and in large format world, f/5.6 is considered fast. However, even a fast lens must be stopped down eventually to obtain adequate depth of field. Obviously, as you close the aperture, the image darkens...no matter how fast your lens is to begin with.
Which brings us to screen quality. All screens will be brighter in the center and then fall off as you move away from the center hotspot. This light falloff can often be quite dramatic (as you'll see below) depending on the quality of your screen. Can you imagine composing an image without being able to see the entire scene at once? This is often an obstacle that large format photographers face on a regular basis.
And so it was with my camera. The two places I photograph most often, the Smoky Mountains and Zion National Park (you know, just like everyone does) are filled with many dark compositions. Combine that with the fact that, after some research, I discovered my Shen Hao camera comes with about the worst possible ground glass ever made. After nearly a year spent guessing at both composition and focus, I was becoming frustrated with the results I was having. Both of my lenses are blazing fast f/5.6s. It was time for a new screen.
But where to start? It's not like you can pick these things up at Wal-Mart! Although I do think it would be a bit humorous to go into the electronics department and ask for a ground glass for my camera...well, maybe only humorous to me. Anyway, to the Internet I went. After a bit of research, it was clear that there was one screen to rule them all: the Maxwell Screen. Stories of this screen were the stuff of legend. There were rumors of photographers composing images BEFORE the sun came up! Unheard of! I knew I had to have this immediately.
However, it wasn't quite as simple as placing an order and waiting for delivery, because...wait for it...Maxwell Screens does not have a website! I didn't even know that was possible in this day and age! Some more research got me an email address and phone number (which I will happily share to anyone who is interested). I sent an email to Bill Maxwell, and he responded a few days later requesting we talk over the phone. This was expected as all the forums I read had said Bill will want discuss options with you to make sure you have the best screen possible. They also said Bill will want to talk...quite a bit.
I must say, though, that I did not find this to be the case. Certainly Bill was very thorough in describing how the screens work and the different options available. From speaking with him, I learned that Maxwell Screens are actually extremely high quality fresnel lenses combined with a ground surface. The design of these screens is basically a compromise. As the screen gets brighter, you sacrifice directionality (Directionality refers to looking at the screen at an angle versus directly in line with the screen. The brighter screens have a much smaller viewing angle.) In the end, I decided to go with their brightest screen, the Hi Lux Ultra Brilliant Matte. At just north of $500, this was a difficult pill to swallow, but I reasoned that I had to see what I was shooting in order to make all of this worthwhile. In related news, I am now MUCH more careful about how I pack my camera on trips!
A few weeks later, my screen arrived and I set about installing it. The screen actually comes in two pieces: the Maxwell Screen itself and a protective glass screen that goes on the outside. Installation instructions came with it, and it was quite straightforward. First, I unscrewed the brackets holding the old ground glass in place and lifted it off the wooden rails holding it. Next, I placed the Maxwell Screen on the wooden rails with the ground, matte surface facing the lens and the concentric circles of the fresnel facing the back or viewing side of the camera. Finally, I placed the protective glass sheet on top of the screen and replaced the brackets. One note about the brackets, as Bill told me during our phone conversation, on Shen Hao cameras they'll have to be bent a little bit (see video). This is due to the fact that to begin with they were only holding a single piece of glass in place. Since the Maxwell Screen consists of two pieces, the arms of the brackets will have to be bent a little bit to accommodate the added thickness.
Best money I've spent in large format, and it's not even close. First, I'll let the below images speak for themselves. To conduct this test, I focused the 4x5 camera on a picture I have hanging in our basement. The picture itself is illuminated with overhead lights, and there is no ambient light in the room. I placed my digital camera on a tripod, and the exposure remained constant in each test. Furthermore, neither the 4x5 or digital camera was moved so directionality remained the same for each image. I tested three screens: the original Shen Hao ground glass, the Shen Hao gg w/a generic fresnel lens, and the Maxwell Screen. None of these images have been edited.
Worth every single penny. Just look how bright and evenly illuminated! Even to the far corners. I have used this screen for almost three months now, and I can tell you that it is as good as advertised. On my trip to Zion, I had absolutely no trouble photographing Subway and the Narrows, two notoriously dark locations. I could easily see into the corners, even when stopping down. It was really a joy to focus and compose with this thing!
There are several considerations though. First, the Ultra Brilliant screen I ordered is VERY directional. Even straying a few degrees off center will completely black out the screen, as seen in the video. Second, there is a "sweet spot" when viewing the screen. It is approximately two feet behind the camera. Viewing here lets you see the entire image. As you move closer, it starts to get dark at the edges. I found myself composing the entire scene from this "sweet spot" and then moving in closer to check for focus. Also, I was a bit concerned about the fresnel lines and being able to focus, but the image is so bright that this turned out to be a non-issue. Finally, you'll still have to use a dark cloth. Not because of screen brightness, but because of how shiny and reflective the protective glass is. Without a dark cloth, you'll just see a reflection of what is behind you.
These really aren't cons though, just nuances of a new piece of gear. Again, I cannot recommend this screen enough. I'll wrap it up with this story that I believe is really telling of the quality of the Maxwell Screen. While at the Subway in Zion, there was another 4x5 shooter there. As us large format guys are a small fraternity, we started sharing stories and talking gear. I told him he had to step under the hood and check out the screen I had. After seeing it, he was absolutely blown away by how much brighter my screen was than the one that was on his camera. It wasn't until he was leaving that I realized I had left the polarizer on my lens when he was looking through it...