Archive for the ‘Equipment Reviews’ Category

Gear Guide: Solar Power in the Field with Goal Zero

July 25, 2012

This week’s Gear Guide video is all about solar power — something I have become quite familiar with over the past few years. In this episode, I showcase various products, and discuss their effectiveness in the field.

Fuji Velvia 100 vs. Kodak Ektar 100: Round 2

September 26, 2011

In my last post on this topic, I compared the performance of Fuji Velvia 50 to Kodak Ektar 100. Though wildly popular among landscape photographers, Velvia 50 is a notoriously unforgiving film. It is not well suited for long exposures. For that reason, I occasionally use Fuji Velvia 100.

Many years ago, Fuji thought it was a good idea to discontinue Velvia 50. They replaced it with Velvia 100, which created quite the stir. Why discontinue something that is so loved? Fuji touted Velvia 100’s significantly improved reciprocity failure characteristics. While very true that Velvia 100 does better with long exposures, it often suffers from a strong purple cast during sunrise/sunset conditions — and especially while using graduated neutral density filters.

Needless to say, Fuji made the right decision, and brought back Velvia 50.

During my annual pilgrimage to Zion National Park last November, my goal was to photograph Subway with my 8×10 camera. This scene is best photographed in the late afternoon when a dominant glow appears against the rear wall of this narrow canyon.

Otherworldly: Kodak Ektar 100 8x10 | Several Minutes @ f/45

The above photo was taken at f/45 using a polarizer in a very dark canyon. To capture a scene like this on large format, you will need a very long exposure.

Velvia 100 does quite well with the long exposures, but check out what happens to the color under these conditions.

Not only is the color very blue/purple, but the high contrast scene leads to issues with the highlights and shadows. In all fairness, this is a direct scan from my Epson V700 flatbed. Unlike a drumscan, my flatbed cannot pull complete tonality from the original film. When viewed on my light table, there is adequate tonality in the highlights, but the shadows are definitely lost.

I exposed this scene so the brightest highlights registered just over +2 on my spotmeter. The deepest shadows fell in the -3 to -4 zone — The zone of no return on slide film. There’s nothing wrong with having rich dark tone in a photo, but this simply wasn’t the look I was going for.

So why did I bother to bring Velvia 100 if I knew the color would be so bad? Simple, I knew exactly what to expect from it, and I could always tweak the color back to reality if possible. Velvia 50 would give better color, but my exposure would be well outside the range of acceptable exposure times.

Unlike most color print films that benefit from a bit of overexposure, Kodak Ektar 100 must be treated more like a slide film. In my round one comparison, I found that Ektar provided the best exposure when rated at the standard ISO while shooting a relatively low contrast scene. I bracketed my exposures, but decided the base ISO was best. As I exposed brighter, I began to lose my highlights.

Most manufactures provide a reciprocity failure correction table. Put simply, if your exposure time exceeds a certain limit, you need to increase the exposure. Film does not react to long exposures on a linear scale. Velvia 50 is among the worst for reciprocity failure. At 4 seconds, you need to start adding extra time. By the time you reach a minute, you must double your exposure. If you fail to do this, you will end up with an underexposed photo.

Here’s the problem. Kodak does not publish any reciprocity failure statistics for Ektar. They simply tell the end user to experiment and see what works best. That’s a bit difficult on 8×10. At $20 a shot, simply bracketing an exposure means $60. Yikes!

After shooting a sheet of Velvia 100, I removed the film holder, and replaced it with one loaded with Ektar 100. I was using an unproven (to me) film in a high contrast, long exposure situation. I didn’t even have published reciprocity failure numbers for this film, so I went with my instinct.

I took a total of two frames. My plan was to expose one at +1, and a second at +2. The first shot went just as planned; I simply doubled my exposure. During the second shot, I chickened out and cut the exposure short. I gave it +1.5 stops rather than +2. I’m not sure why I decided to cut it short — but it seemed to make sense at the time.

Laid side by side on a light table, there is only a subtle difference. Upon close examination, I prefer the exposure with +1.5 compensation. The highlights are similar for each, but I gain just a hair more shadow detail on the +1.5 version.  Here’s what it looks like when scanned as a positive. Check out the detail on the right side.  Though in deep shadow, there is a lot of information to work with.

If we think back to the original exposure, the brightest highlights were metered around +2.3. By adding +1.5 stops of exposure, they would now be metered at +3.8. Had reciprocity failure not been a factor, I would certainly have severe issues with the highlights. After all, Ektar 100 is a film that must be treated more like a slide film.

Though I am ultimately unsure of the exact reciprocity failure numbers for Kodak Ektar 100, I am now confident in giving at least an extra stop of time for long exposures. I don’t recall the exact exposure for this scene, but I know it was measured in minutes — perhaps 2 or 3.

This photo of Subway represents my first gallery grade image on Kodak Ektar.  With this shot, Ektar has earned a spot in my regular rotation of films. I look forward to using it on my next trip, along with Kodak’s Portra 160.

Fuji Velvia 50 vs. Kodak Ektar 100: Round One

May 23, 2011

Yes, there are 2 bottles of Hershey syrup in my fridge. Why 2 bottles? ...why not?

When I tell other photographers that I sold my $8,000 Canon 1Ds III for a wooden box, I am often met with confusion. My late Canon 1DsIII was among the best of the 35mm based digital cameras. Why on earth would I give up such a camera?

It’s the look of film, and the warmth that it gives an image. I love the soft gradation of tone, the tangible sense of the grain, and the palette of subtle colors that are perceivable only to the most diligent eye. When viewed up close, a digital print can never match the warmth of analog film. I have nothing against Katy Perry, or other modern “digitally mastered” singers, but when you compare her songs to the rich, raspy voice of Ray Charles in his famous “Georgia on My Mind” — there is no comparison. This is the feel I get from film.

If I was late in my career with a head full of gray hair, this past statement might come across as a “Get off my lawn!” moment. It still may be so, but I’m only in my (very) late twenties. Also, I’ll have you know that I don’t have a lawn — I have a wonderfully desert-scaped front yard. “Get off my crushed rock!” just doesn’t have the same appeal.

Taking up large format film required a steep learning curve, but not where you might think. Operating a large format view camera is quite simple. The learning curve involved two major bumps along the road.

Bump in the Road #1: Metering

Learning how to properly expose a photo using my Sekonic 558, was a process of trial and error. It took several months to become comfortable with easy exposures. More difficult exposures (dynamic scenes, extreme contrast, etc) took the greater part of two years to become familiar with. Now I am very confident in my metering ability.

Bump in the Road #2: Learning Different Types of Film

The second hurdle was understanding, and learning to work with a variety of different film types. The first film I tried was Fuji Velvia 50. It was by no accident that I chose this film to start with. It is favored by landscape photographers because of it’s high contrast, and brilliant saturation.

Velvia 50 also happens to be one of the most difficult film emulsions to work with. Errors in exposure are greatly magnified, resulting in a photo that is horribly under, or overexposed.  Also, exposures as short as 4 seconds require extra time due to reciprocity failure. In fact, Fuji doesn’t even recommend exposures that are metered longer than 1 minute. This is a major issue for us large format shooters. Even on a sunny day at mid-day, my 8×10 camera often requires 1 full second.

Taking up large format on Velvia 50 was baptism by fire — a very colorful and contrasty fire.

I now have 4 different film stocks within my rotation: Fuji Velvia 50, Fuji Velvia 100, Fuji Provia 100F & Kodak Ektar 100. With much trial and error, I have learned the strengths and weaknesses of each.

Of the films I listed, one stands apart. Kodak Ektar 100 is a color negative film, whereas the Fuji films are all color slide film.

The advantage of slide film is that you can easily see the results with a light table and a loupe. If the exposure is spot on, viewing a sheet of large format film on a light table is a magical experience. The photo has dimension and depth.

The disadvantage of slide film is that there is a very limited range of tones. If your dark tones are a bit underexposed, this detail is gone forever.

Color negative film is more difficult to evaluate with a loupe, but it’s exposure latitude is stunning. A high contrast scene is not a problem for color neg film. A well exposed sheet of color neg film will knock the socks of any digital capture.

This leads to the heart of this post.

Last November in Zion National Park, I shot a frame of Kodak Ektar along side Velvia 50 (or Velvia 100) for nearly every photo. This provided me with a (relatively) well controlled comparison between the most notorious slide film for landscapes, and a relative newcomer in the large format market. It was only last year that Kodak began producing Ektar 100 in 4×5 and 8×10.

Kodak Ektar 100 vs. Fuji Velvia 50 (Round One)

At $20 a click, it seems almost wasteful to shoot a sheet of 8×10 Ektar for every sheet of Fuji Velvia 50 on my Zion trip. As mentioned in my trip journal, I was hesitant to use Ektar as my primary film on that trip because of the lack of reciprocity failure data. Most of my shots would be in dark canyons, often times requiring exposures several minutes in length.

Round one consists of a photo of a forest floor covered with freshly fallen maple leaves. The light source was a canopy of backlit leaves, combined with the glow of a towering sandstone cliff on the other side of the canyon.

I scanned these two strips of 120 film with an Epson V700 scanner. No color adjustments were performed upon scanning. I merely set the levels to provide the best possible scan.

photographed with Fuji GX617 medium format camera (click to enlarge)

The biggest difference is of course the color. The Velvia 50 shot has a very warm tone, leading to potential gamut issues with the red leaves.  Although the Ektar shot is far more subtle, it could be warmed up to match Velvia 50 if desired.  Which is more accurate? Check out this frame grab from my Video Journal for Zion 2010 Day 5.

The color in this video can’t be used as an ultimate truth since it too has been digitally processed. However, it does seem to match with my memory for the scene.

Strictly from a color perspective, we can conclude that in warm reflected light, Velvia will exaggerate this color, and Ektar will be a bit on the cool side.

I can easily tweak the Ektar shot to resemble Velvia if I chose to do so. Conversely, it would be difficult to bring the Velvia photo back to the realm of normalcy without losing depth.

crop of Ektar/Velvia 50 Comparison (click to enlarge)

When viewed up close, the color difference is even more profound. We now focus our attention on individual leaves. Without a doubt, the Ektar shot looks more realistic. The Velvia shot looks like someone hit the “Nuke” button in Photoshop a couple dozen times.

This should be no surprise, since we all know that Velvia 50 is a very saturated film. It is interesting to see a side by side comparison though.

My next crop is designed to show the range of shadow detail contained in each film. Remember that this is just from my Epson V700 flatbed scanner. A drum scan will retrieve even more detail.

(click to enlarge)

Notice the dark area near the center of each crop. The Ektar 100 is definitely showing much more shadow detail. Also, look for the rock at the 5 o’clock position of my first 100% crop sample.

Needless to say, I’m very impressed at the depth I’m able to get from this film. I have yet to drum scan any shots taken with it, but strictly from a color/tone/contrast perspective, I really like what I see.

This example was in even light, and the exposures were relatively fast. No reciprocity failure correction was necessary. I exposed this shot at ISO 100 as directed.

I bracketed my exposures for this scene in 1 stop increments (-1, 0, +1).  In the end, I selected the ISO 100 shot as the best exposure.  Although the difference in exposure was not significant, I recommend sticking with the rated ISO in these conditions.

In my next comparision, I compare 8×10 Ektar 100 to Velvia 100 (Yes, I know some of you just cringed), within some VERY dark slot canyons. You might be surprised what I have to say about that.  More to come…


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