Mitutoyo Microscope Lenses

Mitutoyo is the king of macro! The legendary lens! A dream for years!

It’s also expensive, requires a lot of ancillary equipment and is hard to find. So there’s a lot of history. A bit of personal history, a bit of confusion, a bit of reasoning, a bit of technical issues… I can already tell this is going to be a long article.

Equipment competition

It was a long time ago when I took my first macro photograph. I didn’t know I was going to be obsessed with it, I thought, “How fun!” But the desire to explore is a very strong emotion. I got hooked and devoted all my free time to macro. Countless pieces of equipment passed through my hands. The drawers were overflowing. I didn’t know what I was trying to achieve.

The few sentences I have written so far actually describe a period of 5 years full of photography. Without going through them so quickly, I need to share this scene in my bedroom, which looks like a flea market exhibition, to make you realize how complicated things are these days. 

As this obsessive state continued, I gradually realized that I enjoy what I do regardless of the equipment I use. Whether I use cheap or expensive lenses, the photographs I produce satisfy me.

Then, out of curiosity, I experimented with a lens that was very affordable at 30 Euros, but not suitable for macro at all, and published it as an article: Macro shooting test with Tokina 80-250 zoom lens. When I looked at the photos, I felt that I should be a little more logical. Even if the equipment was bad, the result was not bad when used correctly.

Then John Hallmen conducted a survey. In response to the “that body is better than this one”, “that lens beats this one” debates that were on the agenda at the time, he published photos he took with competing systems and asked people: “Guess which photo was taken with which lens!” You can guess the result. They couldn’t. John Hallmen summed it up: “A good photographer takes good pictures with all of them!”

After all this, my mind was clear. I was going to stop the equipment competition(Or?)

Price/performance balance

With every purchase, we wonder how much we will get for our money. When I look back at my own decisions, I see that I tend to go for products with low prices due to the customs tax limit of 75 Euros, as I constantly shop abroad.

I tried a lot of equipment, all second-hand, some forgotten, some undiscovered, and some of it hit the bull’s eye (Lomo 3.7X, Componon-S 80mm). These lenses became famous and their prices multiplied. Others were so bad that they were just window dressing (like the Lomo 20X).

But overall, I made a very good investment. I would recommend a similar slow-moving and risk-free plan to anyone new to macro. Take the time to get to know yourself and your equipment and don’t spend big bucks until you love macro shooting. 

Don’t say, “We still haven’t reached Mitutoyo, what is he talking about?” It really takes a long time to get there, I’m trying to give that feeling. This stage we have reached is the limit. With this equipment you can take pictures forever and be happy. That’s the end of it.

Luxury goals

Or you keep raising the bar and agree to pay a lot more for maybe a little bit better. And you usually do this for one of two reasons.

1. Modern, expensive lenses with their eye-catching MTF values, gleaming coatings and test/evaluation articles that reek of advertising can leave you with an itch in your stomach as they wink at you.
2. When you get older, you don’t have as much energy as you used to! Again, we may say what is this related to the subject, but here it is. We have a macro chat group of 6-7 people. Are the popular topics among us lenses? Actually yes 🙂 But we often talk about the following:
   • Friend A: He has weak sight so badly that he cannot read the lines of a micrometer.
   • Friend B: He has a herniated disc in his neck…He doesn’t want to bend down and take pictures.
   • Friend C: Herniated disc. He can’t bend down either.
   • Friend D: He has just had surgery on his eye.
   • Friend G: Let it be me. He had surgery and hasn’t been able to take a proper photo for 2 months.

Get well soon to all of us. I hope they are laughing while reading 🙂

Expensive equipment does not always produce a better quality result. That’s what I meant by price/performance. So far, I have tried to stay away from the “itch” issue in point 1. For example, when I had the Componon-S 80mm and Lomo 3.7X lenses, I didn’t go after the MP-E 65mm. I invested more money in the “low energy” part I mentioned in point 2. In other words, I spent extra money on products that can be considered luxuries like a modern body, quality tripod, quality rail, quality bellows that provide comfort and speed in shooting along with ergonomics.

Then the itching started!

Choosing the next lens

I wanted the next step to be a big one. I had a choice of different lenses that I could use for a certain magnification, but I couldn’t just say this is the best one and use it all the time, because it wasn’t clear which one was better. I had to find the “best lens” that would make a significant difference and make a choice that I would always use for that magnification.

First I had to choose the magnification value. When I group them by use value, I can divide them into wide angle, 1:1 magnification, 2X-3X range, 5X and 10X. When I looked at 5X and 10X, 10X seemed too troublesome to me. Since 5X appeals more to general use, I used my preference in this direction.

The lens I was going to choose for 5X had to be a lens that would close the search for 5X forever! The choice was already clear: Mitutoyo M Plan Apo 5X.

Mitutoyo

I don’t remember when I first heard the name Mitutoyo, but I clearly remember how the sample photos I saw left my mouth open. All of the well-known macro photographers around the world were Mitutoyo owners. They must have known something if they all preferred it! When I look at my e-mail correspondence, I intended to buy Mitutoyo in 2012 and did price research. In other words, it has adorned my dreams since the years I started macro.

The Mitutoyo is an industrial microscope lens of the infinity type. So we have to use it in front of another 200mm lens. We call that lens a tube lens and the quality of the tube lens directly affects the result. Choosing a tube lens will be another challenge and expense.

But why Mitutoyo?

• Mitutoyo is a very sharp lens. Contrast is also very high. Blacks come out exactly black. Sharp enough to hurt your eyes 🙂 The first time you use it, you might even feel like it’s too sharp and artificial! 
• It’s a real APO. You don’t get CA color distortion with this lens. You get natural colors. Most microscope lenses give serious CA distortion. It was with this lens that I realized how white the white feathers are. They are not pinkish or bluish!
• Mitutoyo creates an image large enough to fill the sensor of a full-frame camera. So it’s full-frame compatible. You don’t have the problem of corner darkening or reduced sharpness in the corners.
• It has an incredible working distance. Most microscope lenses work so close that they almost touch the object. You can’t illuminate, the shadow of the lens on the object and the reflection of its own image is too big. This is not the case with Mitutoyo and it is very easy to illuminate the object.
• When we focus on different depths of the subject while focus stacking, the frame does not change! This is something to be appreciated. Even though Mitutoyo is not fully telecentric, the perspective does not change due to the working distance, which brings great efficiency and ease in processing the images. With other microscope lenses, the change in frame and perspective is sometimes so great that the area you see in the final image is only half the area in the first image. Then half of the frame in the first photo is garbage. We cannot see that part after the process is finished. Since the changing frames during focus stacking have to be resized and superimposed by the software, there are shifts that affect the resolution of the image. In Mitutoyo, the image is always full frame and the resolution is always high.

Let’s get a Mitutoyo!

It doesn’t just happen when you say it!

First of all, it is an expensive lens. It is definitely expensive for me since I live in Turkey. Edmunds Optics, one of the official sellers for the US, lists a price of $705 for 5X and $885 for 10X. European prices are in Euros and higher than US prices. I don’t know about postage costs, but it’s obvious that a nice customs fee will be added.

Options like eBay are easier, but there is a trust issue. You need to find sellers that you can feel comfortable that the lens we are going to buy is really new. But since there is no Paypal in Turkey at the moment, this door is currently closed.

The Turkish distributor gives a list price of 1141 Euros for the 5X. When you add VAT on top of that, it exceeds 2 times the US price.

Although second-hand is more affordable, I don’t recommend it unless you buy from someone you know. Mitutoyos are industrial lenses. They may have been used under very severe conditions. You may come across lenses that have been used kicking and slapping while there are statements such as “Do not drop them!” on their boxes. As a matter of fact, a friend of ours had a very bad experience with a second-hand Mitutoyo. While trying to repair the lens that came in worse condition than expected, the lens became completely unusable.

Note: Never open Mitutoyos for maintenance and repair! They are assembled in a robotic environment with micron-level precision. Even if we rotate the windows inside a little bit without changing their position, problems can occur. They are not the same when opened for repair in a place other than their own service.

So?

So it is impossible to say which way to go for the purchase. After setting Mitutoyo 5X as my goal for 2016, the plans have evolved very quickly in a positive direction. Before Paypal closed down, there was a good shopping opportunity on eBay.

All the shots and descriptions below were taken with the Mitutoyo 5X. But all Mitutoyo’s models are excellent lenses, especially the 10X and 20X, which are well suited for macro. All the praise applies to them too.

First impressions

Finally, my package arrived. I opened it with great excitement and here is Mitutoyo! 

The first thing to notice is the size. It is too big for a microscope lens! When you pick it up, there is a second surprise because it is so heavy! It’s a monster. You can use it for defense! If you throw it, it can break heads and eyes. Let’s see what it looks like when we put it side by side with the Lomo 3.7X, an average-sized microscope lens:

Mitutoyo is a giant. Thanks to this huge front glass, it can deliver high NA and long working distance at the same time. Here’s how it works:

• Mitutoyo 5X, NA value 0.14, working distance 34mm
• Mitutoyo 10X, NA value 0.28, working distance 33.5mm

These are incredible numbers. It is like a dream for a 10X lens to focus at a distance of 3.5cm 🙂 Nikon 10X, which is a cheap lens in my hand, lags behind with NA 0.25. And the working distance is only 7mm. When we look at the glass size, we immediately understand why. The front glass of the lens is the size of a pinhead!

Note: Use NA values only to compare lenses of the same magnification. Do not make a decision based on NA only. If you take a random 40X lens with a NA of 0.65 and think it gives more detail than the Mitutoyo 5X with a NA of 0.14, prepare to be disappointed. 

Now it’s time to use this giant. Our next challenge is choosing a tube lens. 

Tube lens

Tube lenses are used focused at infinity

I said that a 200mm lens should be used as a tube lens. We can calculate the magnification by mathematical proportioning for different focal length lenses. I had candidates for both daily lenses and enlarger lenses.

• Componon-S 80mm
• Makinon 80-200mm
• Pentax K 200mm f4
• Pentax K 135mm f2.5

If I were to compile a list of favorite tube lenses, it would be a very long list. I’m only going through the lenses that I own and have had the opportunity to test directly. There are some people who use tube lenses that are much more expensive than Mitutoyo itself.

Of course, it is not easy to use every lens we come across as a tube lens. We need adapters to convert the filter diameter of the tube lens candidate to M26 connection. Unlike most other microscope lenses, Mitutoyo’s have an M26 connection, not RMS. Moreover, the screw pitch of this M26 is strange: M26X0.7. 

Since my two Pentax lenses have a 58mm filter diameter, I bought the 58mm to M26 conversion adapter earlier. I wish I had bought it much, much earlier! The adapter must be made to order because it arrived even later than Mitutoyo and when it arrived, the paint was still sticky wet! I had to wait 2 more days to dry it before using it. You don’t want to glue your Mitutoyo to the adapter, do you?

As usual, I covered the necessary parts of the adapters with light traps so that the internal reflections do not reduce the contrast. The inside of this adapter has a metal surface that can reflect light. It should always be coated there. Don’t be surprised by the white colored paper visible on the inside on the left in the photo above. That part is outside the optical area. The optics only sees the part with the hole. Otherwise, I would not have missed this detail. There should never be a reflective part in the area seen by the lens.

In the case of the enlarger lenses for the tube lens test, I connected the Mitutoyo with the same adapter after increasing the filter diameter to 58mm by inserting other adapters.

Mitutoyo lenses have M26 type connection

Some gave strange magnifications and severe corner darkening, while others were not suitable in terms of sharpness. Deciding was going to be more difficult than I thought. After many, many test shoots with millimeter paper, I got some very different results, as you can see in some of the examples below.

An ideal tube lens should be 200mm. I chose a grasshopper from the insect specimens I had to do a full test using the Pentax 200mm, which looked good. The shooting phase was very exciting 🙂

The result is a big smile on my face 🙂 Mitutoyo showed its power not only in details but also in colors in the first shot. I will have a lot of fun with this lens, but there is a problem: The grasshopper is too big! At 5X magnification its portrait overflowed the frame. I need to take a second shot with a 135mm tube lens to make the lens work at a lower magnification. This time the magnification will be 135/200*5 = 3.4X. I am a bit worried. Since I’m using a full-frame body, there is a high chance of problems in the corners.

Happiness again 🙂 There is a slight loss of sharpness in the corners, but it’s no big deal. It is quite possible to reduce the lens to 3.5X. This was very pleasant. In most microscope lenses, we cannot achieve a reduction rate of 30%. Especially with full frame bodies. Mitutoyo deserves another congratulations.

Changing the magnification/framing

This grasshopper is a good example. 5X magnification was too much, so we used another tube lens and worked at 3.5X. So it’s very important to be able to change the frame and magnification depending on the size and angle of the sample we are shooting.

What if I didn’t have a 135mm lens? How would I reduce the magnification then? Or what if I had to work at 6X? Isn’t it our right to ask for a little more magnification?

We have two solutions for this.

• Using a zoom lens as a tube lens. For example, with a zoom lens like 70-300, we can get different magnifications as we change the focus value. For 200mm we get the magnification of the lens itself, while for 300mm we increase the magnification by 1.5 times. But zoom lenses are usually not very sharp. I don’t have a zoom lens except an old 80-200. I got very bad vignetting with the 80-200 and gave up using zoom lenses altogether. It is up to you to try other zoom lenses.
• Using a bellows. You know that in normal macro use we adjust the magnification by changing the bellows length. It’s the same with the tube lens. If we connect our tube lens in front of the bellows, we can increase the bellows length and increase the magnification. But if we want to both increase and decrease the magnification according to the situation, then we need to turn to a different option.

Raynox as tube lens

You know Raynoxes. They are famous as very high quality close-up lens attachments. There are two prominent models: DCR-250 and DCR-150. I have been using the DCR-250 model for a long time and I wrote an article to introduce it: Macro close-up filters

The DCR-250 model has a diopter value of +8. This value translates into a focal length of 1000/8= 125mm. So the DCR-250 can be used as a 125mm lens. Then if we mount it in front of the bellows and put Mitutoyo in front of it, we can get a 125mm tube lens. If the distance from the Raynox to the sensor is 125mm, the DCR-250 will be focused at infinity. In this case the magnification value is 125/200*5 = 3.1X.

If we want to increase the lens to 5X, we continue to increase the bellows length. It is even possible to go up to 7X by opening it even longer. I took a sample shot by staying around 5X again. It gave a very satisfactory result.  

Raynox is also very light, which makes it very comfortable to use. Together with the bellows, it offers a very flexible solution.

This photo above received Honorable Mention in the Nikon Small World 2019 competition. Thank you Mitutoyo.

After that, my research on tube lenses continued and I saw very positive reviews about the other model, the Raynox DCR-150. The DCR-150 has a focal length of 1000/4.8 = 208mm with a diopter value of 4.8. It seems to be a better candidate as it is closer to 200mm. 

You can order Raynox add-ons directly from Amazon. That’s what I did, it comes directly to your door. And the prices are usually more favorable than buying from Turkey.

The recommended connection method is to use Raynox in reverse. In this way, especially in full-frame bodies, edge sharpness is more successful. So I decided to improve my setup in this direction and ordered the DCR-150. But there was another issue that caught my attention in the pursuit of perfection: Aperture!

Background problem in microscope lenses

Let’s look at the problem first. Microscope lenses are unrivaled in sharpness, but they have a challenge. The depth of field is extremely shallow! “What the hell, that’s why we do focus stacking,” we might say. And this is true. Nevertheless, an aesthetic problem bothers me. 

Example: Portrait of “longhorn beetle” taken with Lomo 3.7X

Now look at this photo. Even enlarge it, there are great details 🙂 We can call the Lomo 3.7X a little Mitutoyo. But something bothers me. The body of the insect is present and continues to exist in the background, but it has fallen so fast and hard into the blurred area that it seems to have emerged from another dimension and extended its head. The beetle’s head looks like a cut mask. The sense of integrity and depth is damaged.

In this work of 61 photographs, the focus depth in each frame is very thin. All together, the head is brilliantly clear, but then what?

And then we’ll use a diaphragm.

External diaphragm

Our normal lenses have an aperture. It comes to our help when we want to emphasize the background. By reducing the aperture, we can increase the depth of field as much as we want. Microscope lenses, on the other hand, have no diaphragm, so we don’t have such a possibility.

Or do we have?

Yes, we do! We can use an external diaphragm. If we place an external diaphragm just behind our microscope lens, we can increase the depth of field by reducing the aperture. 

Shooting at a reduced aperture on a microscope lens is normally not a good idea. Since we are already working at the limit of light diffraction, aperture reduction will quickly make us lose sharpness. But in two cases it is a very good idea. 

• For lenses with significant CA chromatic aberration, reducing the aperture by 1 unit provides a balance between sharpness and CA aberration and also makes it possible to work with fewer photos because it increases the sharp area.
• At the end of the focus stacking, when we shoot only the last (rearmost) frame with the aperture closed, we make the background visible and provide depth and continuity in the photo. Since the rearmost frame targets the already blurred background, the loss of sharpness caused by the aperture will not matter at all.

For example, I worked with the Nikon CF Plan 10X lens by slightly closing the aperture to eliminate CA. Since external apertures do not belong to a specific lens, there is no value written on them. When opening and closing, they work continuously, not click click click. Therefore, when we say we want to close it by one unit, we cannot do it randomly without measuring it. This is how I did the measurement:

I measured the exposure time with the aperture wide open. Let’s say it gave 1 sec. Then I continued to measure the exposure time by closing the aperture little by little. When it gave 2 s, I stopped reducing it there. When the exposure time increases by 2 times, we understand that the aperture is closed by one unit. Similarly, you can calculate other aperture values by proportioning over the exposure time.

To illustrate the effect of aperture on depth of field, I’ll share two photos, one with the aperture wide open and one with the aperture closed way down.

I think my point is well understood 🙂 The sharpness is not sharp in the last shot but the aperture did its job very well by bringing out the background. Adding this last image to the focus stacking sequence will smoothly bind the background. You can find the final version of this photo and more at the bottom.

Creating the setup

I’ve written and drawn so far, but I haven’t mentioned how all these pieces fit together. If you haven’t asked yet, you’re in a bit of trouble. We have a puzzle on our hands. Now let’s get to that part of the job. You will spend a lot of time, money and wait a long time for the orders to arrive to make this installation. I plan to save you (as it happened to me) from spending more money and waiting longer for faulty orders and trials.

And that’s the beauty we’re trying to create:

I confess that when this installation was completed, I was in awe for a long time. With the excitement of my childhood, I said, “Voltron! Voltron! Voltron!” 🙂 Those under the middle age may not know this cartoon, but when all the pieces came together, the giant robot Voltron emerged, kicking up dust! 

Now let’s gather those who want to experience the same excitement.

A pinch of bellows, as many extension tubes as your eye likes, a fresh Raynox, enough adapters, a medium-sized diaphragm and a blossoming Mitutoyo 🙂 This is our recipe. The cooked version will look like the one above. Now we will look at these ingredients one by one.

There is one component that is not in this picture, but I must remind you of it: The precision rail. You can’t do this with the rail of the bellows itself. For Mitutoyo 5X, I shoot with 20 micron stepping. Without a micrometer rail, you can’t do a focus stacking work that shows constant sharpness. Unfortunately, you cannot move forward without solving the rail problem.

The second issue is the bellows. If you are going to use a 200mm lens as a tube lens, there is no need for so much trouble. But many users, including me, find Raynox DCR-150 very successful. We choose Raynox as a tube lens for use with infinity type microscope lenses. Using a bellows also provides great convenience in terms of flexibility in changing magnification. I highly recommend this type of system to those who can afford it.

If the rail and bellows are complete, we can lay the rest of the material on the ground:

Of course, as it is, nothing is clear. Let’s take them in order.

1. Extension tube suitable for your bellows. Since I use Pentax bellows, my tube has Pentax mount. It is not mandatory to use a tube. Since the Raynox DCR-150 is 208mm, you need 208mm between the sensor and the Raynox to focus at infinity. This is the ideal value. If your bellows is small and does not open long enough, we can support it with an extension tube. Or if you want to increase the magnification even more, again the extension tube is the solution. I keep it on for flexibility, it allows me to get 5X without pushing the bellows all the way. When I want, I extend the bellows a lot and go above 5X.
2. Reverse 49mm adapter. Since the tube is Pentax, it is also reverse Pentax type. If your system is different, this will be the appropriate reverse 49mm.
3. Raynox DCR-150. We connect it reversed. So the female side, which is 49mm, is facing in. The male side of the Raynox facing outward is 43mm.
4. 43mm-49mm adapter. The 43mm side of this adapter is female and facing inwards. The outer part is male 49mm. The purpose of using this is actually to be able to use the next adapter. Because somewhere in the sequence we need to make a female-to-female conversion. 
5. 49mm-49mm female-to-female adapter. The female-to-female conversion was essential for the next alignment. There are not many adapters that can do this. When I searched, I could only find a 49-49 adapter, so I had to use this one. Adapters number 4 and 6 were also needed to use the number 5.
6. 49mm-52mm adapter. The 49mm side is male and faces inwards. The 52mm side is female.
7. 52mm-M42 adapter. 52mm male side facing inwards. The outward facing part is female M42.
8. M42 diaphragm. It’s already clear how it’s connected. Male side in, female side out.
9. M42-M26 adapter. Finally we have the M26. Of course the inner M42 side is male and the outer M26 is female. And after that will come Mitutoyo.

if we are using an RMS type infinity lens, the last adapter number 9 will be M42-RMS. Everything else is the same.

This male-female issue is very important. Mistakes are often made. When choosing an adapter, we need to make sure that the product we buy is suitable. Otherwise, you’ll find out that male-male or female-female are interchangeable! No matter how hard you try, the adapter

Of course, you can also find a different connection formula. As the range of adapters on the market increases, it is also possible to do it with fewer components. Or if you don’t want to use a diaphragm, the number of parts will be much less.

Mitutoyo without tube lens

Before I close this tube lens issue, I feel the need to satisfy my curiosity a bit more. I’m going to see what happens if I connect the Mitutoyo directly in front of the bellows and don’t use a tube lens at all. There are some optical diagrams drawn for infinite lenses that are confusing. It looks like there is no need for a tube lens. In the discussions in the forums, it is written that using without a tube will create an image but some problems will be seen. Now we need to understand these problems, right?

It is easy to remove the Raynox from the setup above and continue the connection that way. No need for a new adapter. Just remove 3 and 4 from the parts list above. So I immediately set up the system to do this test, targeting a jumping spider. 

When the tube lens is removed, the Mitutoyo makes a real image. And it magnifies much more, which I never expected. I use millimeter paper to set it to full 5X and I have to turn the bellows down quite a bit.

The result is very good! Good enough to beat most of the lenses I’ve used so far. But not perfect. Normally the colors come out completely natural, but this time there is a slight CA. Contrast is slightly reduced throughout the image. And there is a noticeable loss of sharpness in the corners. Use a little bit of Photoshop on all of these problems and you have a seriously good photo.

Mitutoyo can be used without a tube! But would I recommend it? No, I wouldn’t. Why would I use it without a tube when I can get even better images with a tube lens? But we had a good competition, it was a good test.

One more thing to look at before we finish. If we get 5X even with the bellows short, what happens when we extend the bellows?

I say 10X, you say 15X. Any bids?

A realistic estimate would be somewhere between 10X-15X. When I extended the bellows, the magnification went through the roof. But even if our lens is Mitutoyo, it starts to groan under such strain. The result is usable but far from the sharpness I’m familiar with. I don’t enjoy processing this photo.

In microscope lenses, NA values also represent the level of detail to be taken. When we push a lens beyond its purpose, the magnification increases but the NA value does not change. In this case, we can say that the level of detail does not increase much.

When the 5X runs at 10X with a NA of 0.14, it falls far below the Mitutoyo 10X’s NA of 0.28. A 10X lens should be used for the same photo. I am also looking forward to the day when I can reach the Mitutoyo 10X.

Final words

Mitutoyo 5X is one of the best purchases I’ve ever made. I am glad I bought it. I showed the results and made many friends buy it. There are already a lot of Mitutoyo users in Turkey. I don’t think any of them regret it.

Mitutoyo gives fantastic detail. Please click on this photo and see it in full size. There are not many lenses that can give this detail at 5X.

Even with such a nice lens, I can’t produce a large number of photos, because each work consists of around 150 photos. Taking them is the easiest part. After that, the time spent in front of the computer is really long. You better get a fast computer while you’re at it. Sleepless nights are waiting for you 🙂

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My sample photos with Mitutoyo 5X