Rodenstock Linos Rogonar-S 35mm f/4 Line Scan Lens

This is the latest Rogonar-S 4/35 model lens in a industrial all-metal body, there is another more common Leica thread mount version with plastic enlarger lens body. The Rogonar-S is a 4 element, 3 group value-line lens for machine vision and inspection use. This lens was listed in the Linos catalog but has been removed from the Qioptiq online shop and catalog, so it probably has been dropped from current line-up, but they have been pretty easy to find on the used market lately.

Line-scan-camera-Rodenstock-Rogonar-S-35mm-f4-line-scan-lens-www-Closeuphotography-com.jpg

This particular lens, was picked up on eBay in January 2020 for a starting price of only 0.99 cents complete with mount adapter and JAI machine vision camera. Although I already own a 35mm Rogonar-S lens, tested here on Closeuphotography.com: https://www.closeuphotography.com/rogonar-s-35mm-test, this version was 1/3rd stop faster, and the low starting price too good to pass up so I went for it. As it turned out I was the only bidder, but did I waste my money?

One added bonus with the industrial camera setup was that the lens came with a nicely made M32.5 x 0.5 to M42 x 1.0 step-down mount adapter with lock-ring. In the latest Qioptiq/Linos price list, the adapter alone goes for $67.99, this price is for the step-down adapter, not the lens.

TESTING THE 4/35 Rogonar-S at 2.5x MAGNIFICATION

2500 PIXEL IMAGE SAMPLE

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. The URL, at the top of the browser, 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 full-size image.

Rodenstock Linos Rogonar-S 35mm f/4 Line Scan Lens at 2.5x

2.5x results

The results out of the 4/35 Rogonar-S at 2.5x are nicely detailed, sharp and no chromatic aberrations. The overall IQ is better than I would expect from a low-end 4 element machine vision lens. For the price, I don’t see how you can beat the performance on an APS-C sensor. Moving up to the more expensive 6 element top-of-the-line Rodagon 4/35 lens does not get you any more performance, I compared the two Rodagon samples I have, and the results out of the Rogonar-S seem to be sharper than the 6-element design. I plan to post the results of the shootout as soon as I can get time to finish processing the files.

100% Crops

This lens isn’t perfect, the sharpness and fine details do fade towards the corners as you can see in the 100% crops. The drop-off is not bad as bad as a typical 50mm enlarging lens or a microscope objective with a 25mm field number (Nikon for example).

Front lens: Rodenstock Linos Rogonar-S 35mm f/4 Lens reverse mounted
Rear lens: Mejiro 90mm f/5.6 lens normally mounted focused at infinity
Stacked lens nominal aperture: f/4.0
Stacked lens effective aperture: f/10.0

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 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.

For best results I use this lens in a stacked configuration. Stacking lenses, also called coupling lenses, is a technique where you mount a lens in reverse, or face-to-face, on a second lens, usually a telephoto lens. With the rear lens set to infinity focus and with the front lens reverse mounted there is no loss of light due to extension. Together the combination has the potential to resolve more than either of the lenses setup for close-focus with extension.

An f/4 lens focused at 2.5x magnification by extension would have an effective aperture of f/14 using the simple formula, effective aperture = nominal aperture * ( Magnification + 1 ). With the same lens setup in a stacked configuration the effective aperture would be only f/10 using the formula effective aperture = nominal aperture * Magnification. You can predict the maximum possible resolution from a certain lens by using the simple fact that a wider aperture = higher potential resolution.

TECHNICAL DETAILS

Linos Rogonar-S 1:4 f=35mm
Lens applications: Machine vision, inspection, vision streaming applications
Part number: 0801-273-100-00-0001a
Filter threads: M30.5 x 0.5
Focal Length: 36.4mm
Barrel type: All-Metal
Optics: 4 elements in 3 groups
Mount: M32.5 x 0.5
Iris: 5 blades
Maximum Aperture: f/4
Optimized magnification: 0.05x
Coverage: 25mm image circle

Quick Review

What I Like:

Compact all-metal body
Impossible to beat price/performance ratio
Image quality is very good when setup in a stacked configuration
Decent CA correction, low distortion, better than the six element 4/35 Rodagon!

What I Don’t Like:

What’s not to like?
Impossible to complain about anything for the price paid
Since this lens came with a mounting adapter I can’t even complain about the odd-sized mounting threads

LENS DATA

From Rodenstock: “ Rodenstock MTF curves are calculated. The reality is when you measure MTF curves on the MTF machine with a lens it could have a tolerance of -10 %."

Linos Rogonar-S 1:4 f=35mm MTF vs Linos Rodagon 1:4 f=35mm MTF

Note that the field scale at the bottom is different for the two lenses, so the full diagonal on the Rogonar-S is only about half-way across on the Rodagon graph. There seems to be a big difference between the two lenses but in the real world setup with a stacked configuration, the Rodagon lens is actually not as sharp as the Rogonar-S at 2.5x.

OTHER 30-35MM LENSES

All the lenses below have been tested, at least one sample, for this site, some like the Canon MP35, at least 3, the Tominon, at least 5 samples have been tested. The Componon 35? I’ve tested at least 8 or 9 samples.

Spiratone, Vivitar, Prinz, 35mm f/3.5 Lens: Below average perfomance compared to the Rogonar-S, Rodenstock or Schneider 35mm lenses. Leica thread mount.

Canon MacroPhoto MP 35mm f/2.8 Bellows lens: Flat field and full frame coverage but an older design so there are some lateral CAs. Used prices vary widely on eBay. RMS mount.

Minolta 30mm Rokkor CE: Not recommended. M39 x 26 tpi, Leica thread mount. No filter threads. Excessive chromatic aberration problems. Can be expensive.

Minolta E. Rokkor 30mm F4.5 enlarger lens: Expensive, hard to find. Chromatic aberration. Rogonar-S is better. No filter threads. Leica thread mount.

Noritsu 32mm f/4: Excellent performance, highly recommended. Not common on the used market. M40 x 0.75 mount.

Rodenstock Eurygon 1:4 F=35MM: Expensive, hard to find. Performance is not as good as the Rogonar-S, or Tominon 35mm. M40 x 0.75 mount.

Rodenstock Rodagon 1:4 f=35mm Enlarging Lens: Not worth the used market prices. Performance is not as good as the Tominon 35mm or Rogonar-S 35mm.

Rodenstock Ysaron 35mm f/4 Enlarging Lens: Ysaron is same design as the current 4 element Rogonar-S design. Don’t pay too much for this lens on the used market.

Schneider Componon 35mm f/2.8 Makro Iris: Excellent performance, highly recommended. V38 V-mount.

Schneider Componon 35mm f/4: Excellent performance, highly recommended. Easy to find. Leica thread mount.

Schneider Xenon 35mm f/2: Excellent performance, highly recommended. Hard to find. 25mm x 0.5mm mount.

Tominon 35mm f/4.5: Highly recommended, especially for a stacked setup, but sample variation is an issue. M40 x 0.75 mount.

LINKS FOR MORE INFORMATION:

The Rogonar-S 35mm f/8 Industrial lens here on Closeuphotography.com: https://www.closeuphotography.com/rogonar-s-35mm-test

$2.50 Rogonar-S v $250 APO-Rodagon-D v $1K Canon MPE Test discussion on Photomacrography.net forum:

https://photomacrography.net/forum/viewtopic.php?t=40477&

The older Rodenstock online catalog with the Rogonar-S 4/35 lens listed: http://www.rodenstock-photo.com/Archiv/e_Rodenstock_Printing_CCD_43-62__8230.pdf

The Linos Machine Vision Lineup including the Rogonar-S lenses on the Qioptiq site, the Rogonar-S 35mm lens is not listed in this PDF:

http://www.qioptiq.com/download/Rodagon_Leaflet_en_web_sml.pdf

Rodenstock Linos Rogonar-S 35mm f4 machine vision Lens Test