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Photography with projection lenses

by Güray Dere
Projection lenses

The story part of what I am about to tell is a bit old. So we can call this a long overdue article. I’ve been using projection lenses for a long time, so I have to back up the beginning a bit.

As a macro photographer, I chased detail and sharpness for a long time. Once I got used to it. Macro or not, a photograph had to be razor sharp. I had to be able to count eyelashes if necessary. I tried many lenses for this purpose, some of which I discarded without even testing them.

It’s a disease…

A test in search of sharpness in portraiture: The Rodagon 150mm enlarger lens. Click on the photo for larger size.

It took a long time, but it was a very enjoyable journey. Once I had satisfactory equipment, I enjoyed it for a long time.

I don’t know when it happened, but I found myself spending a lot of time on manual lens forums, bokeh and flare themed threads. I started to follow people who bought 100 different lenses with the same focal value and were still looking for a new one.

The guy would pick up one of the lenses and take a picture of the brushwood, and without any Photoshop effects, a colorful impressionist oil painting would emerge.

It turns out that what the elders used to call “optical imperfection” has turned into a nostalgic and artistic tool that makes a difference against the perfect and monotonous optics of modern times.

Old manual lenses are a subject that is endless to try and endless to explain. In this article I will touch on a small but special area that I find fascinating: Projection lenses.

Portrait / Bokeh photography

Wide aperture lenses are often sought after for portraiture.

It is said, ” Lenses in the 85-135mm focal range are good for portraiture. The wider the aperture, the more it kills the background and emphasizes the subject”.

These values are really not bad. They usually say, “The kids look beautiful.” But the kids always look beautiful. I want the background to look beautiful too! So I don’t want to kill the background. Why should it have to die? Do we live in space?

But making the background part of the photograph requires composition. You have to think and move and find the right position and angle. And that’s not possible with children running around. So killing the background without a second thought and focusing only on the portrait does a good job of capturing the moment.

Briefly, the soft bokeh, like melted cream, manages to create a sweet, serene and eye-soothing mood. It’s a nice tool to keep the viewer floating in the smooth tonal transitions and ultimately locked into the subject.

If we are looking for fun, fantasy and difference, we can try boiling the background instead of melting it!


Although it is usually thought of as the background, any place that is not in focus is included in this definition. In other words, both front and back bokeh character have a separate and strong effect on the photo.

It was when I was using an aps-c camera. My cousin brought his new full-frame mirrorless camera to test it. I put on my Helios 44 lens, which I had tried normal and reversed but hadn’t tested it properly. While looking through the viewfinder, I was surprised for a while by the sight of the sparkles of light leaking through the tree leaves.

Helios 44M-4 58mm f2.0 swirlybokeh effect on full frame body

The swirly bokeh creates a hypnotic effect.

Here was the Helios’ famous “swirly bokeh”.

This character of the lens was especially evident at the corners, and as long as I was using an APS-C sensor, this beauty was cut off and out of the picture. I became more interested in characteristic bokeh after this experience and found another reason to use a full-frame body.

My obsession with sharpness ended there. When I was using APS-C, I convinced myself that “the center of the lens is sharper, we get rid of the distorted areas on the edges and it’s great”. For example, our eye sees the center very sharp, but the sides are blurry. So do we wear blinders so that we can throw away the sides, see it cropped and make it sharper?

After this experience, my next lens would be for portraiture, not macro, and it would make itself noticed. At least that was my dream.

Bubble bokeh

After following bokeh photography closely, I realized that one style in particular is very popular. These lenses, which produce ring like soap bubbles, create the appearance of a fantastic world. The lens that achieves this best or is the best known among them is the Meyer Trioplan 100mm f2.8.

Celebration all a-round
A photo taken with Trioplan 100mm f2.8 – Photo: Dhina A

I was familiar with this len, and I’d seen ads for sale with metallic silver bodies that were in poor condition and rusted. Sometimes the aperture was broken and stuck. That’s okay, I was going to use it wide open anyway, that’s the only time the bubble bokeh would appear. The ads didn’t look very good, but they were $50-$60. Those were the prices I remember.

I checked eBay and queried the Trioplan 100mm, but ouch! $700s and $800s are all around! This lens has become unattainable. There are other models of Trioplans, like the 50mm f2.9, going for $30-$40. It too has ring bokeh, but not like the 100mm, just small rings. I don’t think it’s suitable for portraiture, and while I’ve been scorning it ever since, this lens is going for over $150!

The situation is bad. I keep going back to the forums and discussion groups and watching the bubble bokeh flying around. The more I read, the more options I have. I learned that the lens design called Cooke-Triplet was very old and all of these lenses delivered bubble bokeh. Most of them had already gone up in price. Then, hidden treasures started to appear in junkyards.

Projection lenses

In elementary school, they showed us a black and white movie about petroleum. I remember being very impressed. I had never been to a movie theater before. The black and white film strip, which was spinning in front of the flickering light of the old film machine, was projected onto the screen through a projection lens. I was attracted to the machine as much as the movie. That lens was perhaps the same lens I use now.

Prokyon 6x6 Projector on Display (01)
Dia projector and its lens – Photo: Hans Kerensky

Projection lenses are found in slide machines, movie theaters and modern projectors that we connect directly to the computer. They project the image onto a white screen or wall.

Since these lenses are not made for cameras, there is no easy way to connect them to the camera body. So we can’t find a standard projection lens adapter to mount them on a Canon, Nikon, Sony, etc. system. Each lens has its own weird screw system. Sometimes not even that.

Their structure is usually in the form of a tube. We are talking about a metal tube with some glass inside. They have no mechanism for focus adjustment! They don’t have a diaphragm either! The diaphragm is the tube itself, think of it as a lens that always works wide open.

Their use on cameras has become widespread with mirrorless bodies. Mirrorless cameras have almost unlimited possibilities to use lenses. If we can somehow attach the lens to a helicoid or a bellows to provide focusing, it is ready to shoot. As you expand the bellows, the lens focuses closer, and as you narrow it, it focuses farther away. Just like primitive cameras with bellows.


Meyer company has now been re-established and they are producing old lenses again, including Trioplan. But are they as good as before?

Trioplanes are famous lenses from a German company called Meyer Optik Görlitz. There are other legendary lenses produced by this brand a long time ago. They used the same optical formula of triplet type in different models. In other words, lenses that produce bubble bokeh are frequently encountered.

When I was browsing the forums and heard that some people were getting bubble bokeh with Meyer’s projection lenses, my interest shifted in that direction. Because they were hard to use and therefore cheap alternatives. Among them was the Diaplan 100mm f2.8, which was said to be the same as the Trioplan. It was like a Trioplan 100mm without the focus ring, aperture and bayonet.

I wasn’t expecting so many Diaplan models on the market. There were 80mm, 100mm and 140mm Diaplans in the listings and aperture values ranging from 2.8, 3.0 and 3.5. Since the 100mm f2.8 model I was looking for was not available, I bought another one I could find at the time: 100mm f3.5

Diaplan 100mm f3.5

The lens arrived. It was tubular, as I expected. But I was lucky and was able to find the 100mm in its own focusing helicoid. I wouldn’t have to bother with a bellows, it would be very light and ergonomic. However, it was still not possible to connect the focusing mechanism to the camera.

Pentax compatible Diaplan 100mm f3.5 with Pentax adapter glued to the back

I have plenty of adapters. I decided to glue one to the back of the lens without much consideration. Since I was using Pentax at the time, I glued the 49mm reverse Pentax adapter to the back of the focus mechanism. The lens was suddenly Pentax compatible. Of course, it can now be used with my Sony body without any problems. I can focus both at infinity and at very close range.

Diaplan 100mm f3.5 ready to use on Sony body

Diaplan is a sharp lens. There’s nothing wrong with using it at wide open aperture. It’s super light and super compact. It produces a nice bokeh. The bubble effect I dreamed of is not very strong but there exists enough. Given a suitably shimmery background, the bubbles stand out.

The main difference in using Sony/Pentax that I mentioned above is the sensor size. Since the corners of the image are cut off in the APS-C body, I get the image in the center and the lens gives a more rounded bokeh. So they look like bubbles.

Diaplan 100mm and bubble character bokeh on APS-C body.

Things change a bit with the full-frame body. The roundness of the bokeh disappears towards the corners and a change towards a half-moon shape. Even if it moves away from the Trioplan character in this form, it looks like a Helios-style swirly bokeh that looks very nice to my eyes.

Diaplan 100mm f3.5 on a full-frame body. The bokeh changes towards the edges.

After these first tests, I’m beginning to suspect that the Trioplans may have been overrated. You don’t easily call a lens worth $800 useless. It would be painful to say, “My bubbles are a bit deflated” after all those photos that others have pushed into our eyes and received a lot of applause. And one cannot sell a lens that has been labeled a bad copy at the price he bought it.

I mean, what if the king is naked? Nobody publishes raw photos. Could it be that they’re pumping the contrast and sharpness to the max and inflating the bokeh balloons on the PC? Such an over-processed hormonized photo or not, Trioplan seems to keep its value as long as it provides the raw material for processing.

As a result, I really liked the 100mm f3.5. It was a lens that I felt special while using it. I share my Diaplan 100mm photos as an album. The ones with cats were taken with APS-C sensor.

Diaplan 140mm f3.5

When the search for bubble bokeh continues and I decide to try another Diaplan for tests, I choose the 140mm to be a little different from the first one. Since it is a tele lens, I expect a big bokeh ring. There were no tests or sample photos when I placed the order. Let’s see what comes out.

When the lens arrives, it turns out that the attachment is a bit tricky. The body is tubular again, but this time it doesn’t come with a helicoid. So I have to use a bellows to focus. The thread system of the lens is put on the inside of the tube. So it’s a female type. The coupling is possible, but I need to find out the length and diameter of the screw pitch.

I need a quick test. Since I don’t have a suitable adapter, I take a shot with the lens in my hand in front of the bellows. The bellows feels too long even at the shortest. So it works like a macro tube. The lens cannot focus at long distance. 140mm is too close when I shoot from only 1 meter. If this is the case with a mirrorless full-frame body, I don’t think it can be used at all with a mirror APS-C. The bokeh character is soft but it doesn’t give the shape I want. I put the Diaplan 140mm aside for about 1 year after this experience.

Diaplan 140mm on full-frame body with bellows.

In the meantime, the equipment I have acquired for two different purposes has breathed new life into the way I use projection lenses.

  • External diaphragm: I bought this for controlling the depth of field in microscope lenses. They can also be used in projection lenses that are naturally diaphragmless. It’s the diaphragm’s job to sharpen the lens and interfere with the depth of field.
  • Helicoid adapters: I use a helicoid adapter as a macro tube to force wide angle lenses into close-ups. Normal macro tubes are too long for wide angle and make focusing impossible. If we use a helicoid adapter for focus adjustment on projection lenses, we get a focus device small enough for lenses like Diaplan 140mm that have difficulty focusing far away.
Diaplan 140mm on a full-frame mirrorless body

The connection for the Diaplan 140mm turns out to be a female m58mm. The external aperture is of the M42 type and I choose the helicoid adapter as Canon. To connect them all together I use a series of adapters as shown above. I need to add an extra 20mm M42 tube in between. With this 20mm, I can extend the focus distance of the lens to ∞ – 1m. If I don’t use it, the lens can’t focus closer than 5-6 meters. It’s exactly what I wanted, let’s move on to the tests.

I’m a bit excited to use the 140mm with diaphragm for the first time. I take my model, who was calmly nibbling carrots inside, out into the garden and put her in the hammock 🙂 The diaphragm and lens show a performance that surprises me. Again, there are no bubble bokehs as I dreamed of, but there is a distinct “swirly bokeh” instead! As I close the aperture, both this effect gets stronger and the lens becomes quite sharp.

Diaplan 140mm used with external diaphragm

There is no doubt that I will test this lens a lot in different light conditions in the future. I’m adding a new one to my list of favorite lenses for portraiture. Below are some examples I shot with the Diaplan 140mm. New photos will be added here as they arrive.

Zettar 150mm f3.0

One day I’m browsing the listings for projection lenses, and when I come across this lens called Zettar, there is almost no information about it. It is obviously made for Zett brand projection lenses. It is also more or less known to be a “triplet” design. I took a significant portion of the lenses I have at my own risk and bought them without any information, relying only on my feelings. Again, the urge to explore prevails and I place the order.

Zettar 150mm f3.0

The lens has a rather rough flat metal body. Of course it has no mount. Again, it has a female thread system and you can’t really tell what it is. I do the first test by holding it in front of the bellows with my hand. The lens is not sharp and very sensitive to light. I don’t expect nanotechnologic lens coating because maybe it is from 50 years ago. But it is clear that this is the most sensitive lens I have in terms of flare. I start looking for an adapter by saying that I will use it with a lens shade.

Zettar 150mm f3.0 on mirrorless full frame body

The screw type thread comes out 49mm. There are reverse M42-49mm adapters produced for reverse lens attachment to M42 body cameras. When I attach this to the front of one of the small m42 bellows, the lens fits directly into the bellows. It’s not in the photo above, but I’m also putting an M42 diaphragm in front of the bellows so I have aperture control.

Rain of bokeh with Zettar 150mm f3.0

The lens is literally raining bokeh. And they’re bubbles. Yes, it’s not sharp. But I love the bokeh so much that I don’t even think of closing the aperture to increase the sharpness. I accept the lens as it is.

Soap bubble bokeh with Zettar 150mm f3.0

The flare effect, which I thought might be a disadvantage on first impression, is a joy in itself. The possibility of flare, as opposed to using a lens shade, is what makes me prefer this lens. There’s no need to go out of your way to do something different. The moment we come across the sun, the fun begins. It’s like watching fireworks.

Rainbow of innocence
Flaming bokeh
Glare in the eye

I loved the Zettar so much that I couldn’t take the risk of losing it and started looking for a backup. After a long search, I finally put a second one in my drawer and relaxed. It was this lens that showed me how strong the bokeh and flare character of a lens can be and ended my obsession with sharpness. The evening sun is best enjoyed with Zettar. Sometimes I dream of wearing these two Zettar on both eyes and seeing the world like this 🙂

Let’s see what’s on the Zettar album:

Final words

You choose, melting background or boiling background?

Projection lenses are a bomb that has exploded in the world of photography in recent years. I know people who take a few sample photos with lenses they collect from the garbage dump or attic and then sell them for hundreds of dollars. There are many useless ones among them, but many undiscovered gems are lying in antique shops and scrapyards.

I bought all three (actually 4) of these lenses at very funny prices. As far as I can see, this is no longer possible. But the opportunities still continue. Most importantly, the excitement of discovery continues. I will continue my tests and searches, and I will spend time sharing about the world of photography beyond macro and the lenses I find special.

I recommend projection lenses for anyone who loves photos with unique character and fun.

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