Rogonar-S 50mm f/3.5 Industrial Lens
This Rogonar-S 50mm lens has a pre-set aperture of f/3.5, which is a little unusual since industrial lenses like this are typically slower, maybe f/4 to f/8. Faster is usually better since the larger aperture has the potential to make sharp imager images with more resolution at higher magnifications.
Industrial lenses are attractive since they are usually sold for just a fraction of the original list price so even if these are not as easy to install or setup as a consumer market lens like an enlarging lens, they can be a very good buy for the experienced macro photographer.
Rogonar-S 3.5/50 PROs
Fast f/3.5 nominal aperture measures out at f/3.3
All-metal body should be vibration and dust proof
Low-cost
Small compact design
Rogonar-S 3.5/50 cons
No mounting threads
Unknown wavelength, coverage, magnification design range
3X Test: 2500 pixel sample image
Click on the image below to view a larger version in a Lightbox viewer, but the size of the image sent to your device is based on the size of the screen being used. To open the image in a new window or 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 and compare the images in the image viewing app of your choice.
To check the size of the image you are looking at, look up at the URL window at the top of the browser, the address should have 2500w at the end. If the image size is anything smaller you can easily change the number to 2500 manually and press enter to bring up the largest image.
The image quality produced by the Rogonar-S 3.5/50mm at 3x is a nice surprise with consistent sharpness and contrast across the sensor from corner to corner with good chromatic aberration control. In my experience the performance of this lens is better than it should be for a simple 4 element lens design. It’s nice to see a lens that breaks an old rule in photography, this one being that 6 element lens will always outperform a 4 element lens, at least it’s just not the case at 3x.
ROGONAR-S 3.5/50 TECHNICAL DETAILS
Rodenstock Rogonar-S 1:3.5 f=50mm
Lens applications: industrial
Part number: Unknown
Filter threads: none
Barrel type: All-Metal
Optics: 4 elements 3 groups
Mount: none
Iris: aperture disk
Nominal Aperture: f/3.5
Measured Aperture: f/3.33
Coverage: APS-C coverage is very good
Used market Price: $5 for new-old-stock
3X Test: Setup
Test notes: The Componon-S 150 lens and the Rogonar-S worked well together with less chromatic aberrations than the Rodagon 5.6/150 that I tried originally. Also this test was originally done with less magnification, at 2.2x, but the APO-Rodagon corners were very poor where the Rogonar-S corners were very good. Be sure to check out the sample image above at 3x at the full 2500 pixel size, its pretty impressive I think.
Front lens: Rodenstock Rogonar-S 3.5/50, ID label towards the sensor.
Rear lens: Schneider Componon-S 5.6/150, normally mounted focused at infinity
Stacked lens nominal aperture: f/3.5
Stacked lens effective aperture: f/10.5
Front lens: Rodenstock APO-Rodagon-N 2.8/50, reverse mounted
Rear lens: Schneider Componon-S 5.6/150, normally mounted focused at infinity
Stacked lens nominal aperture: f/3.5
Stacked lens effective aperture: f/10.5
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
For this test I ran a stack of images in 4 micron steps 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.
100% VIEW CENTER CROPS: ROGONAR-S 3.5/50 VS Rodenstock APO-Rodagon-N 2.8/50
Click on the image below to view a larger version in a Lightbox viewer, but the size of the image sent to your device is based on the screen size. To open the image in a new window or 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 and compare the images in the image viewing app of your choice.
In the central area it looks like the sharpness is very close between the two lenses, the APO-Rodagon might have a slight advantage in contrast but that comes with more pink fringing, I prefer the cleaner blacks in the 4 element Rogonar-S image where there is less pink fringing. I prefer the better green color in the APO-Rodagon image.
100% VIEW off-CENTER CROPS: ROGONAR-S 3.5/50 VS Rodenstock APO-Rodagon-N 2.8/50
Off-center the lenses are also very close in sharpness, but the APO-Rodagon does have a small lead but comes with increased pink fringing the blacks and along the white diagonal line down the middle from left to right. The Rogonar-S image is warmer.
100% VIEW CorneR CROPS: ROGONAR-S 3.5/50 VS Rodenstock APO-Rodagon-N 2.8/50
Now in the corners the Rogonar-S has a slight edge in sharpness. Also the Rogonar-S has less pink or red fringing around the letters in the blacks, look at the 6-7-8. The 6 element APO-Rodagon-N is considered a premium, top-of-the-line lens, the Rogonar has a more simple 4 element design.
3X test Results
These two lenses are closer than you would expect at 3x but I prefer the cleaner Rogonar-S image with similar sharpness and better chromatic aberration control. The results are interesting since the APO-Rodagon is supposed to have highest resolution and color neutrality being apochromatically corrected, but it looks like someone in the Rogonar-S design department didn’t get the memo.
MOUNTING THE ROGONAR-S 3.5/50
Unfortunately I do not own any adapters to fit a 22mm diameter lens and I don’t know of any that are made. I just happened to have a Schneider C-mount to M42 step-up adapter that has a ID that matches the barrel of the Rogonar-S. I used a layer of thread sealing tape to get a tight press fit.
Other Rodenstock Lenses Tests on closeuphotography.com
Rodenstock Ysaron 1:4 f=25: coming soon
Rodenstock Ysaron 1:3.5 f=30: coming soon
Rodenstock Rodagon 4/28: https://www.closeuphotography.com/rodagon-28mm-lens-test
Rodenstock Rogonar-S 8/35: https://www.closeuphotography.com/rogonar-s-35mm-test
Rodenstock Rogonar-S 1:3.5 f=50: https://www.closeuphotography.com/rogonar-s-50-lens-test
Rodenstock Rogonar-S 1:8 f=57 : https://www.closeuphotography.com/rogonar-s-57mm-lens-test
Rodenstock Rodagon 1:8 f=60: https://www.closeuphotography.com/rodagon-60mm-lens-test
Links For More Info
Rodenstock Rogonar-S 2.8/50 Enlarger Lens data sheet at the Qipotiq site: https://www.qioptiq-shop.com/out/Graphics/en/00120747_0.pdf
Rodenstock Linos machine vision lens lineup at the Qioptiq site: https://www.qioptiq-shop.com/en/Precision-Optics/LINOS-Machine-Vision-Solutions/LINOS-Machine-Vision-Lenses/?