Rodenstock Ysaron 240mm f9 Tube Lens
October 5th 2021 Updates
240mm Full Frame Tube Lens Test With The Ysaron 240mm
The results of the full frame test with a Qioptiq Mag.x 5x LD Plan and Ysaron 240mm lens is being finalized now and will be posted here as soon as possible. The Ysaron 240 results were better than expected!
RafCamera Ysaron 9/240 Thread Mount Adapter
Right now I’m testing a RafCamera sleeve type thread adapter that slips over the lens with Thorlabs SM2 threads on the outside collar with 3 hex set screws that secure the adapter with a ring, so the set screws will not damage the finish of the lens. SM2 lock rings can be used to secure the lens inside a SM2 lens tube. The adapter was custom made and cost $30, which is twice the cost of the lens, but its worth it since it makes the lens more usable and convenient.
Rodenstock Ysaron 240mm f9 Lens
Before coming across this Ysaron industrial lens on eBay I was completely unaware these lenses existed in an industrial cylinder type mount. Ysaron lenses were were marketed in the 1970s, below the premium 6 element Rodagon lens line, and have been replaced by the current Rodenstock Rogonar - S lenses which are also four element, three group designs used in industrial applications like scanning and machine vision. In my experience the lower-end Rogonar and Ysaron can actually outperform the high-end Rodagons. Ysaron are classic Tessar 4 element 3 group designs made for a range from 2x to 20x, or 0.5x to 0.05x. These lenses use highly refractive lanthanum glass which has radioactive Thorium added to modify its optical properties. Generally consumer type lenses with lanthanum are generally not hazardous so don’t worry.
This lens was supplied with an actual measured focal length, which is standard for industrial lenses. This Ysaron is marked as an f/9, but I found the lens to be slightly faster at f/8.5 forward, and f/8.3 in reverse. This lens should push down using a short-focus setup, close to 200mm.
To be completely honest I didn’t really expect much in the way of performance out of this lens, but keep reading, it turns out to be a nice surprise.
This lens was purchased from a used equipment dealer on eBay without any discount, credit or commission for this post. There are no affiliate links, banner ads or visitor tracking on this page, just 100% free content.
Ysaron 240mm f/9 tube lens with box and caps
QUICK REVIEW
Hard to find 240mm focal length tube lens pushable down to at least 200mm
Good image quality at 240mm
Excellent image quality at 200mm
Very good CA correction
Industrial all-metal barrel
New-old-stock units available for a very low price
Unbeatable price vs performance value
WHAT IS A TUBE LENS?
To use an infinity-corrected objective for photography, you will need a tube lens in addition to the main objective, or the system will not focus, since the tube lens is a required part of a infinity-corrected optical system. The tube lens can be a telephoto lens, a close-up diopter, or a tube lenses designed for a microscope. To find out if you need to use a tube lens with an objective, it's easy to check, infinity-corrected objectives are identified with the infinite mark (∞) on the side of the lens barrel.
In general speed does not seem to be an indicator of performance with tube lenses, in fact I find it to be the opposite, faster lenses, in my experience at least, seem to make poor tube lenses. Slower lenses like the Makro-Symmar 5.9/120 and Mejiro 5.6/90 appear to perform best at the smaller apertures required when used in a stacked configuration as a rear lens. Faster lenses with maximum apertures from f/2.8 to f/4 seem to have issues with chromatic aberrations when stopped down by the front lens in a lens in a stack.
The magnification obtained by an infinity-corrected objective is the ratio between the focal length of the tube Lens and the objective. The most common tube lens focal length used by Mitutoyo and most other manufacturers is 200mm, Qioptiq uses a 250mm tube lens. With infinity-corrected objectives you can change the tube lens focal length to create different magnification ratios at the camera sensor, without compromising the color correction. To calculate the system magnification for different tube lens and objective combinations, you can use this simple formula: Effective magnification = Marked magnification X the new tube lens focal length / the system tube lens focal length.
Rodenstock Ysaron 240mm f/9 tube lens
Rodenstock Ysaron 240mm f/9 TECHNICAL DETAILS
Rodenstock Ysaron 240mm f/9
Rodenstock part number: Cat No 4401162
Filter threads: none
Focal length: The Ysarons tested here were supplied with the actual measured focal length, 241.1, and 240.3
Mount: none
Type: most likely industrial applications like scanning and machine vision
Iris: none
Nominal Aperture: f/9. Measured f/8.5, and f/8.3 in reverse. The lens box is marked f/1,9 in error.
Forward or Reverse Mount: The image quality is good in both directions, but it seems that the flat side forward (as opposed to the retainer ring side) seemed to be slightly better in terms of CAs. Also, the focal length was slightly different in each direction.
Current Retail Price: Available in new-old-stock in factory packaging for $14 on eBay as of May 2019. See the auction link at the bottom of the page.
Rodenstock Ysaron 240mm f/9 with Raf adapter
Mounting the Ysaron 240mm
The barrel of this lens measures 41.5mm in diameter and is 37mm in length. I happened to have a RafCamera 44mm to M42 x 1mm adapter sitting on the shelf that will hold the lens safely with shims. I mounted the lens and adapter inside a threaded Thorlabs 52mm/SM2 tube that is part of my normal 52mm studio setup. For more details on my 52mm/SM2 studio setup and mounting a tube lens, visit this page on Closeuphotography.com: https://www.closeuphotography.com/52mm-setup also: https://www.closeuphotography.com/schneider-kreuznach-28mm-f2-8-componon-lens
test: Rodenstock Ysaron 240mm with the Mitutoyo 5x M Plan APO objective at 6x
Objective: Mitutoyo M Plan APO 5x
A detailed review of this objective is available here on Closeuphotography.com: https://www.closeuphotography.com/mitutoyo-5x-m-plan-apo-objective
Rear lens: Rodenstock Ysaron 240mm f/9 normally mounted focused at infinity, pointed flat-side to the objective (retainer ring towards the sensor)
Extension: 246mm total from flange to the front edge of the lens (the lens is 37mm long)
Camera: Sony α6300, model # ILCE-6300, also known as: A6300
Sensor size: APS-C 23.5 × 15.6 mm. 28.21 mm diagonal. 3.92 micron sensor pitch
Flash: Godox TT350s wireless flash x 2 with one Godox X1s 2.4G wireless flash transmitter
Vertical stand: Nikon MM-11 with a Nikon focus block
For this test I ran a stack of images in 2 micron steps, and was repeated a stack for each aperture. The sharpest frame was then chosen using Photoshop at 100% actual pixel view. Separate images were selected for center, edge, and corner if needed. Each image was processed in PS CC with identical settings with all noise reduction and lens correction turned off, all settings were zeroed out (true zero) and the same settings were used for all of the images.
6X Image Samples
Click on the image below to view a larger version in a Lightbox viewer, but this will only be the largest size image if your screen/window is large enough. The size of the image sent to your device is based on the screen size. To see an image in a new browser tab, right click, or two-finger press, and select Open in a New Tab or New Window from the menu. You can also right click, or two-finger press, and select Save Image As to save and view the image full size.
Rodenstock Ysaron 240mm f/9 + Mitutoyo M Plan APO 5x at 6x. Crop areas are highlighted in blue.
100% VIEW CROP IMAGE SAMPLES
The center crop image is clean and sharp without any issues with chromatic aberrations. I would rate the performance in the center as very good.
In the extreme lower left corner the performance is very close to the center, clean and sharp free of CA issues. I would rate the performance in the center as very good.
Results
The combination of Rodenstock Ysaron 240mm f/9 with the Mitutoyo M Plan APO 5x at 6x is really very good. The IQ is consistent from edge to edge over the APS-C sensor with excellent chromatic aberration control. I would rate the performance here as very good and recommend this lens without hesitating.
test: Pushed down Rodenstock Ysaron 240mm with the Mitutoyo 5x M Plan APO objective at 5.2x
How does the Ysaron 240mm perform pushed down with short focus? I set up the Ysaron with 191mm from flange to the front of the lens, with the lens pointed flat-side to the objective (retainer ring towards the sensor) for 5.2x or equivalent to 208mm tube lens.
Objective: Mitutoyo M Plan APO 5x
A detailed review of this objective is available here on Closeuphotography.com: https://www.closeuphotography.com/mitutoyo-5x-m-plan-apo-objective
Rear lens: Rodenstock Ysaron 240mm f/9 normally mounted focused past infinity, flat end facing the objective.
Extension: 191mm total from flange to the front edge of the lens (the lens is 37mm long)
Camera: Sony α6300, model # ILCE-6300, also known as: A6300
Sensor size: APS-C 23.5 × 15.6 mm. 28.21 mm diagonal. 3.92 micron sensor pitch
Flash: Godox TT350s wireless flash x 2 with one Godox X1s 2.4G wireless flash transmitter
Vertical stand: Nikon MM-11 with a Nikon focus block
Image Samples at 5.2x
Click on the image below to view a larger version in a Lightbox viewer, but this will only be the largest size image if your screen/window is large enough. The size of the image sent to your device is based on the screen size. To see an image in a new browser tab, right click, or two-finger press, and select Open in a New Tab or New Window from the menu. You can also right click, or two-finger press, and select Save Image As to save and view the image full size.
Rodenstock Ysaron 240mm f/9 + Mitutoyo M Plan APO 5x at 6x. Crop areas are highlighted in blue.
100% VIEW CROP IMAGE SAMPLES
With short focus setup the image quality is surprising. The sharpness, contrast and chromatic aberration control is clearly better than the infinity focus images.
The extreme corner performance is excellent as well.
5.2x Test Results:
Excellent. The performance of the Ysaron 9/240 pushed down to 200mm looks similar to the Thorlabs ITL200 and Raynox 208mm, two of the top performers in my Tube Lens Shootout in 2018: https://www.closeuphotography.com/tube-lens-test
Final Verdict: Highly Recommended
The performance of this lens is a really nice surprise, and honestly, completely unexpected. The performance is up there with the very best, especially on a short-focus setup.
I wouldn’t not hesitate to recommend Rodenstock Ysaron 9/240 as a tube lens. The images are very good from center to the corners. On a short-focus setup the images are even better. When you consider the current cost of this lens, $14.99 USD, the lens is absolutely unbeatable from price vs performance standpoint, even when compared to a Raynox lens.
How does the Rodenstock Ysaron 9/240 compare to other tube lenses like the Raynox and ITL200, the the best 200mm tube lenses I have ever tested?
Comparison: Raynox 208, pushed-down Rodenstock Ysaron 9/240, Thorlabs ITL200
Comparing the Ysaron’s center crop image to the Thorlabs ITL200 and Raynox DRC-150, it looks like the Ysaron might be just sharper than the Raynox by the smallest margin and just very slightly less sharp than the ITL200. The difference in sharpness is almost too close to call. The Ysaron introduces slightly more CAs around the edges than both the ITL200 and Raynox.
In the far corners, the performance between the three is close. It looks like the Ysaron 9/240 might give up a slightly in sharpness, there is a tiny amount less purple CAs than both the ITL200 and Raynox. The difference would be hard to notice for most people I think, even at 100% view.
Final Verdict
The ITL200, Raynox and Ysaron are all excellent performers with the Mitutoyo M Plan Apo 5X/0.14, and there is not enough of a difference between them to recommend one over the other based on image quality alone although the ITL200 seems to have a slight edge. But there are other important differences between the lenses. Thorlabs makes an adapter called the SM2A20 that’s designed to integrate the ITL200 into SM2 threaded parts, and since my 52 mm studio set-up is based on the SM2 system, the ITL200 is an easy choice for me. Cost is another factor, and since the supply of cheap ITL200s on eBay has run out, the Rodenstock is looking like an excellent choice even though you would need to buy an adapter.
Judging by the results of this test and the performance of other lenses like the Mitutoyo MT-1, Nikkor 200mm f/4 Ai, and Nikon MXA20696 in my 2018 tube lens test, the Rodenstock Ysaron would easily outperform these three lenses, not only in the center, but in the corners and in CA control as well.
LINKS FOR MORE INFO and where to buy the lens:
Ysaron 9/240 eBay auction link. Normally I don’t recommend eBay sellers but this one is excellent:
Tube lens test from 2018:
https://www.closeuphotography.com/tube-lens-test
Rodenstock catalog with Ysaron lens specs from 50 to 210mm, nothing on the 9/240, this catalog is in French: