Thursday, August 8, 2013

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Posted in Arrangement, Art, Business

Made my own Petzval Lens.... sorta

Figure 1.
Many of my readers know I'm a tinkerer, and I love to experiment and create new hacks out of all sorts of camera equipment.

Today's hack is building my own Petzval Lens.... sorta. I saw in the news that Lomegraphy raised 1 million dollars in Kickstarter to recreate a Petzval lens. So I decided I'd set out and create my own large format to small format hack.

A Petzval lens is simply two doublet lens with an aperture in between the pairs. The appeal of Petzval lenses is the unique swirly bokeh it creates and super sharp central area of focus. Modern lenses has done away with many of those attributes, but in a day and age of hipsters and instagram effects, the popularity of this style of lens is making a come back.

Figure 2.
One of my favourite lenses that creates it's own swirly bokeh is the Nikkor 50mm F/1.2. Unlike the original Petzval that was intended for large format, the Nikkor creates the same effect on a 135 format camera.

The downside to the swirly bokeh is certainly coma and soft edges (coma especially is exhibited on the Nikkor 50mm F/1.2). Special effects lenses like the Lensbaby creates similar effects in a small package that works on the 135 format cameras but becomes way too soft at the edges to be much use than a very specific effect. How Lomography reengineered a large format lens to fit on the smaller format is obviously a mystery, or maybe not. My approach to a similar hack is likely on the same theories.

Figure 3.
Last year I decided to build a large format to digital rig as seen in figure 1. This is built from a Linhof Karden large format camera. Much of the camera bellows and plates are replaced and only the movement controls were kept. This set up allowed me to use anything from medium format lens to large format lenses on my 5Dmk3. A great set-up for tilt and shift photography.

The original bag bellows had to be replaced (figure 2.) with one I sewed together with some special flexible none light leaking material. I created the mounts from HDPE plastic which I cut and formed, and added the hardware for the EOS mount from several old unused adapters and macro tube parts.

On the reverse side, I added a new mounting plate to go directly into the standards on the Linhof Karden.

Bellows mounted
I also needed to make a new plate to go into the rear standard (figure 3.). Composed of several steel and plastic parts with a manfrotto mounting plate to sit the camera on it. It made it easy to put it in and out of the mount. I considered just replacing the standard all together, but I couldn't bring myself to butchering my large format Linhof to do that. It was just as simple to add the plate into the rear standard for use whenever I wanted to use my digital camera with my large format set-up.

Together it made for a nice set up. I also made my own lens boards as you can see in this image, also from HDPE plastic and screws (and yes, it's light tight).

There are a few other photographers out there that have done this hack. I'm not the first to do this, but I have been tinkering a lot with this set up and doing all sorts of experiments, including imaging the entire large format lens, but that requires a different set-up all together.

With recent inovations like the MetaBones Speedbooster, I recognized they used nothing really new to create the amazing ability of fitting the field of view of 135 format to the smaller APS-C formats. The device is merely a focal reducer that in essence shrinks the image circle to a smaller format.

Symmar 150mm F/5.6/ 265mm F/12
In the large format world, there are some lenses that also serve dual purposes. When they are paired in front and back, they are one focal length and take away one of the elements and it becomes another. In these pairs, one of the elements acts like a focal reducer.

Now lets be clear, I'm not a lens or optical engineer. I know enough to be dangerous, but lets to be honest. They are just lenses and the worst I can produce is something that looks like crap.

Because I have a small collection of large format lenses, I was able to go through the various lens pairs and experiment with multiple combinations.

Lens pairs in my large format lens colllection.
My collection also includes some medium format lenses that I butchered. One of the nice combinations I had came from a defective 75mm Bronica lens. As so it happens as I took it apart, it sat in a threaded Compur shutter making it perfectly fine for putting into my independent Compur shutter mounts.

The best lens designs use masking tape right?
After various combinations and experiments, I came up with the conclusion that one of the best combinations to put together would be the rear element of the Bronica lens and pair it up with the rear element of the Symmar lens.

How I tested each combination was using my studio office as a camera obscura. I aimed each lens towards my window, and projected the image onto a white piece of paper. I tried all the combinations until I found one that created a focally reduced image circle (a circle that would only just cover the frame of a smaller format camera).

I took several reference photos, then used a zoom lens to match the same field of view to try and determine what focal length I created. To my surprise, I had something between 70-85mm field of view. I'm too lazy to try and attempt to do math to be certain, but felt that this was close enough.

I have no idea what the depth of field equivalent is and I forget to measure the T-stop to see what I was getting, but what resulted was a very easy to use medium/large format 85mm Petzval like lens with full movements on my 5Dmk3.

The resulting images were surprising. I got great clarity in the centre, and even out to the edges. If I stopped it down, was very sharp across the frame. But wide open it gave me that signature swirly bokeh that Petzval lenses are known for and just enough softness at the edges for that dreamy buttery effect.

Of course this hack (or kludge as my friend Alex calls it) isn't necessarily something that everyone can go out and make. I did make many of these things in the past at a small expense and my personal time. Today I was just playing with lens combinations to see if I could shrink down that 4x5 image to fit onto a 135 format. My son reflects pretty much how I felt about this experiment.
Thumbs up to swirly bokeh! Click here to see a larger version

Wednesday, August 7, 2013

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Lightroom Tutorial - Black and White images that POP

Before and after.

One of the more common questions I hear is how to make an image pop. First we should define what this 'pop' perception is all about.
Figure 1

It's often a trait identified in black and white photos of certain film types and also in some films like Kodachrome for example. This perception is partially to do with a combination of micro contrast or mid tone contrast and colour sensitivities of the film crystals.

Our eyes tend to notice things pop if contrasting colours or even tones compliment each other. But there is much more to it than just adjusting colours within Lightroom, some of this can be done with effects sliders as well. Making an image almost appear to float off the page is a careful balance of your contrast controls, sharpening choices and your effects sliders.

The above image is a good example of when and how we might want to make an image pop off the page. The example on the left is straight out of the camera and although I did like the photograph initially, I had all intentions to turn this particular one into black and white. My eye caught this subject because it already stood off the background, but in the digital representation, it's flattened out somewhat.

It needs some help to cox the subject to the foreground and it does take some careful considerations of what needs to be done first.

Figure 2.
As typical in many of my film simulation exercises, I start with turning down the overall contrast. This helps control my mid-tone contrast later where I will recover it in  individual sliders and various sharpening methods. Most sharpening algorithms are merely mid-tone contrast adjustments which is how it helps make subjects appear crisper in details.

In Figure 1, I compressed the highlights and the blacks from the flattening effect that the reduction of contrast creates and increased the shadow and whites, to bring out tones in both the high end and in the low end. Next I tweak the clarity slider just a little to boost the mid-tones further. Hit the B&W option next.

In Figure 2, you can see this has balanced out the contrast nicely, however it still hasn't completely popped off the page. Yes it's an improvement, but we can still coax more out of this.

After adjusting the B&W filters
The next option is to adjust the B&W slider to suit the image. Because I want contrasting elements, I need to make some arbitrary choices here. The background is almost orange, while the wood of the wagon has lots of yellow. By moving the B&W filtered sliders, I can put both of those colours into two different tonal ranges. By doing this, it separates the elements from each other further, creating a better contrast and illusion of depth.

Arbitrarily I also chose to really emphasize the reds and generally speaking many perceive red in black and white to be a darker tone. So by sliding the slider to the left, I've set Lightroom to respond to red as a darker tone. This is very similar to how some popular silver rich films respond to red. Conversely, sliding to the right would make the red respond more like an infra-red sensitive film and some black and white films like Ilford Pan-F+.

I wanted the red to pop out further so I slid the tones to the darker regions.

Sharpening Options
Sliding the various sliders will give different effects, but the key is making sure none of those sliders are lined up to each other if you have colours that are similar in luminance sitting beside each other. In next example you can see how the wagon has popped off the page after the adjustments. I can certainly stop here and be satisfied, but we can do a little more to make things come off the page.

Vignette options
Sharpening is another contrast tool that we can use. Although Clarity is descent mid tone adjustment (and very popular with many retouching artists), sometimes it can emphasize the wrong things. I generally set up sharpening with a 2 pixel radius setting to balance elements that didn't get a boost from the Clarity slider. Make sure that when you do use a heavier sharpening algorithm, to use the masking option to smooth out any oversharpening errors.

Lastly, I like to add a little vignette to my image to centralize my focus further. This simulates how our human eyes see. For some this is a subjective adjustment but can be done tastefully as long as you preserve important details without making it looking you've just added some round shading to your image (which tends to just look like an overlay). The important point here is to keep the highlight slider maximized to ensure that the vignette mask doesn't affect your primary subject, in our case the wagon. The background gets a nice vignette treatment while preserving your foreground elements. You may need to go back to your B&W settings to adjust things a touch, but ultimately, your elements should pop once you find the right combination of colour filters to use.

Finalize adjustments.

Monday, August 5, 2013

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Posted in Arrangement, Art, Business

It's always my first wedding...

This is the shot that was missed,
which I was able to recover with some
memory recovery software. 
I hear it often and I remember asking the same question, "I'm shooting my first wedding, what are some tips?"

Perhaps this is a little bit of a warning to those just doing this for the first time, but sometimes even after doing as many weddings as I have, you can still make some critical mistakes like I did this past weekend.

I had somehow screwed up my usual workflow and accidentally formatted a filled card from the wedding. But let this be both a warning and also some comfort that it isn't the end of the world.

Regardless of that mistake, I downloaded all the files, and inspected the images. Because I had a checklist of all the things that I needed to get captured, I was able to identify that a single important image was missing. I called the bride and was honest to her and explained the situation.

Next, I drove out to them and took a new photo (they were still partying which was a good thing). I ended up looking like a hero for checking and driving back out to make sure I didn't miss that important shot. Ended up staying for a few more group shots and carried on.

Later on that evening I decided to see if I could recover the card, and to my delight I could. Not surprising, only one picture was really important from it, but despite that I was still glad I called the couple to ensure their important moment was captured.

The important lesson learned:

  • Make Checklists
  • After shooting a wedding, package up the cards into a ziplock bag marked with something like - DO NOT USE, DOWNLOAD FIRST (in fact this is what I do with a national sports event photography company I work for occasionally.).
  • Quick and immediate communication on problems. Be honest!
  • Download to a remote laptop and review on site before leaving (if you have the time to do this of course).
  • Back-up cameras (I had three cameras with me. Fortunately the card I erased was on the back-up camera).
  • Review, review, review.... (this is actually a new lesson for me. I've gained so much confidence with my shooting, I never review my shots. I even shut off the 2 second review in my camera both to save power and also less annoying in darker rooms. But stop once and a while and review when you're shooting a wedding).
  • Purchase Memory Card Recovery software (although I reshot my missing shot, I did end up using a memory recovery tool). The card was reformatted and even had new data on it, however recovery software recovered it all even though it was formatted and had new information written to it (I know it sounds very CSI ish, but there's a lot of information that stays on your card if you never fill it to capacity with new stuff).
  • Don't do weddings. If you are nervous about screwing up, trust me, even though you might actually get to a point about being confident in your shooting skills, beyond that technical things can go wrong, and many of them out of your control.
Weddings and other milestone events can be very fun. But it is a lot of pressure. There's lots of advice out there, but none more important than redundancy, being honest when things go wrong, and just to be very well prepared before, during and after.

Despite all the years of photography, I still make the occasional mistake, which reminds me, look at the process you have in place and figure out what could go wrong, but ultimately, those lessons are hard to identify until something wrong actually happens to you.