Replica meets Authentic: CMH-200 VS ITL200

Background

A seller on ebay under a name comprised of garbled alphabetical mess started selling “Thorlabs ITL200” tube lenses for less than half the price of a new one, shipped. The condition is marked as new, and the photo clearly shows an ITL200 which is very familiar, as it has been used in another listing 2 years ago.

The lens is $180, shipping is an astounding $40, making $220 in total. Despite that, it is still cheaper than Thorlabs’ offering, which is $496.70 without shipping, as of the 9th of June, 2020. The shipping location shows Singapore, which turns out to be a lie.

The ITL200 is actually made by Nikon, in Japan. The tube lens has a focal length of 200mm, which is perfect for Nikon and Mitutoyo objectives.

Photographers in an online chatgroup placed orders on this lens, it was surprisingly shipped from Suzhou’s Industrial Park rather than Singapore. Suzhou’s industrial park as the name indicates, is home to companies in the field of STEM. Having lived around the place for a little more than 7 years, I started to do a little bit of investigation.

Gate of the East Shopping Mall

The photographer who purchased a copy shared some photos of the packaging. The branding shown is “CARMANHAAS LASER”, and the tube lens is called a “focus lens”, which made it sound like some kind of laser optics. Therefore I gave it the name CMH-200, CMH being Carman Haas, the company’s name. Surprisingly, the box also provides insight into the coatings, 400-750nm AR coated. The ITL200 is AR coated for VIS-IR.

The specifications are closer to that of a TTL200, which is optimised for VIS only.

I decided to approach the company very kindly and ask about the lens. Carman Haas is similar to Thorlabs, they are a vertically integrated company that specialises in photonics. Their customer service was extremely polite, understanding, and also shocked at what happened. They claimed that the lens was ordered by a foreign English-speaking customer before the covid-19 pandemic. They made a total of 50 units, and shipped the lot of lenses to another location in Suzhou. This customer is located in a country with very strict customs and high taxation is imposed on imported goods. They told me that it is a common practice for customers from this region to use forwarding methods that allow them to save on taxation. It usually involves someone physically bringing the items into the country. However, due to covid-19, the countries are in complete lock-down. Subsequently, the batch of lens cannot leave Suzhou and the order went bust. The company claims that they did not know the blueprints and optical layout files they received is actually the ITL200, reverse engineered. They went ahead and made the lens.

I cannot comment on the validity of these claims, as I later learned that a member of the forum photomacrography.net received the lens, and the attached address is the exact location of the company’s HQ. This is obviously in conflict with Carman Haas’ claims, as they claimed the order was completed months ago.

My copy of the lens arrived in 7 days, shipped via TNT. No address was provided, the packaging was quite poor, and the tracking traces back to Wuxi instead of Suzhou. Wuxi is another major city that’s close to Suzhou. There is absolutely no branding on the box I received, the seller must have removed it to avoid any legal issues. My unboxing can be found here.

Comparison

The knockoff ITL200 is physically identical to the real deal in terms of dimensions, they also weigh exactly the same, 59 grams. There are subtle differences, such as the retaining ring used. The ITL200 has a matte finish, while the CMH-200 is shiny.

CMH-200 on the left, ITL-200 on the right

The CMH-200 comes with a very neat milky white lens canister which is specifically designed for the tube lens. The ITL200 fits in it just fine. There’s a green sticker with 合格 written on it, meaning quality checked. I removed that sticker.

CMH-200 lens case

Method

To test the performance of the CMH-200 tube lens against the real ITL200, I used my coaxial epi-illumination setup I built for inspection purposes. I used an Edmund Optics 5x Plan Apo objective lens.

The tube lenses can be mounted in Thorlabs’ own expensive adaptor, the SM2A20. This adaptor couples very well with their own SM2 tubing. For users without Thorlabs’ SM2 system, I recommend Wemacro’s M42 adaptor. You may contact William here to get yourself a copy. M42 tubes are cheaper, easier to adapt, and the ones Wemacro sell even come with flocking! Thorlabs’ SM2 tubes despite being high quality, are extremely expensive and there’s no internal flocking.

Wemacro M42 adaptor on the left, Thorlabs SM2A20 on the right

Wemacro’s adaptor allows reverse mounting as well, if one wants to do that. Some say reversing the ITL200 yields better results. From my experience, the results are certainly better for 10x and 5x, but at 20x, reversing the tube lens gives very bad results. I will have to run tests to verify this however. Reversing the lens means I can no longer focus it to infinity, which subsequently means I cannot simply insert planar optics in the optical path between the objective lens and the tube lens, this area is also known as infinity space. My coaxial epi-illumination setup therefore should not be used.

Wemacro’s adaptor

To test the resolution of this lens, I used a silicon wafer chip and focused on the “B” region.

For chromatic aberration, I will be writing a separate article about it. The article will also touch on distortion.

Both tube lenses were focused to infinity by pointing at a distant subject. In my case, it was a gum tree. I used an iris at the front of the tube lens to add contrast and make focusing easier. Normally, an iris is not required in the photomacrography optical system unless stated otherwise by the manufacturer.

I use a Nikon Z6. Stabilisation and diffraction compensation is turned off, I shot a series of images on my stacking rail and selected the best looking one.

Test Images

I am not going to announce which set of images corresponds to which tube lens until the end. Doing so will or should remove any prejudice against the CMH-200, which is a clone.

Please right-click on the sequence of images and choose “open in new tab” or whatever is equivalent to your browser. This will allow you to view them at 100%.

Firstly, let us look at the centre:

The ITL200 is designed for crop sensors, let us take a look at the corners of a crop sensor.

Finally, the corners of a fullframe sensor.

Results

The results are baffling. For the centre set of images, the ITL200 is on the left while the CMH-200 is on the right. They look completely identical, however the CMH-200 does have a very tiny edge when it comes to resolution and contrast.

Regarding to the corners of a crop sensor, the ITL200 set is on the top, followed by the CMH-200. Once again, the CMH-200 wins. This time, the difference is visible at 150%.

When it comes to full frame, it is fair to say that both tube lenses are well out of their comfort zone. This time, the CMH-200 set is on the top followed by the ITL200. Once again however, the CMH-200 edges the ITL200 in terms of resolution and contrast. This is not anything to run home about however, it is like saying wet noodles is a better weapon to slap someone with compared to jelly.

Conclusion

The CMH-200, despite being a clone, outperforms my copy of the ITL200 ever so slightly. The ITL200 is coated for VIS-IR while the CMH-200 is coated for VIS, as the manufacturers claim. This could have an impact on the results.

The CMH-200 only edges the ITL200 very slightly. Absolutely no difference should be expected in everyday shooting. However, the CMH-200 is less than half the cost of an ITL200, inclusive of shipping. Whether the dear reader buys into the companies’ claims or not, regardless of which side of the replica and ethics debate one may be on, the conclusion is clear.

I personally do not mind clones and knock-offs as long as they are done “right”. By right, I mean the following:

  • The knock-off is high quality, would not just break in a week and end up in a landfill, polluting the environment
  • Workers receive fair pay and work in a good environment
  • The knockoff manufacturer is not attempting to pass the clone off as the original

In this case, an eBay seller is trying to pass the tube lens off as the original product, while the company that made it claims that they are oblivious and (sort of) victims too. This depends on whether one believes their story or not.

What I like about the CMH-200:

  • Image quality
  • Nice dedicated case with area for silica gels
  • Price

What I dislike about the CMH-200:

  • Shadiness surrounding it
  • eBay seller attempting to pass it off as authentic

The tube lens itself is innocent. There are certainly problems surrounding its manufacturers and sellers. Putting all that aside, I absolutely recommend the CMH-200. The manufacturer claims that only 50 copies have ever been made, so be quick.

Since I do not endorse the practices of the seller, I will not advertise it here. Simply go on eBay and find it. If it is no longer there, then unfortunately you missed out, or eBay decided to enforce their rules for once and yanked the listing.

Discussion

The results certainly surprised me. I bought the CMH-200 expecting it to be returned on the grounds of false advertising. I did not expect a complete clone to not only hold up against the expensive original, but to beat it ever so slightly. I do not understand why this would happen, maybe better coatings are used? Maybe I drew the short end of a straw when it comes to sample variation?

A contact of mine talked to the company, and they verified that the CMH-200 is indeed a TTL200 clone, not the VIS-IR coated ITL200. They are also the people who were passing this lens off as the original. I was either told a story, or the sales representative I contacted did not know much details, and only had access to stuff regarding to the order. “Someone overseas bought it and due to covid-19, the order went through, and it likely got stuck in their proxy’s hands” is too elaborate and reasonable to be a lie that is made up on the spot. Who knows though?

At the end of the day, the seller is fortunately no longer passing this replica lens off as the original on eBay. They now show the actual item, not a photo stolen from another listing. They are still lying about the location of the item, and it is not equivalent to the ITL200. Oh well, good enough.

Looking closely at the test photos, there are signs of optical misalignment. I have tuned my setup to be as robust as possible. There are certainly many rooms of improvements still.

I do have access to a TTL200-A at the lab I work at. I might ask permission to bring a copy home and test it against the ITL200 and the CMH-200.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this:
search previous next tag category expand menu location phone mail time cart zoom edit close