After two long years of procrastinating I somehow finished the Componon 4/28 page on my site. There is a lot of helpful info for users and potential buyers.
Full test on my site: https://www.closeuphotography.com/schne ... -lens-test
The page also has results from a quick test comparing IQ against the Canon Mpe 65 at 3.5x. For the test, I used a 5.6/100 as a tube lens for the CPN 4/28. The 5.6/100 is not the best TL but they are cheap, I paid maybe $25 for the unit in the test. A good high-performance would show quite a bit better results with the 4/28, especially in the corners.
3.5x SETUP INFORMATION
Schneider Componon 4/28 setup
Front lens: Schneider Componon 4/28 lens reverse mounted
Rear lens: Schneider Componon 5.6/100 lens normally mounted focused at infinity
Stacked lens nominal test aperture: f/4
Stacked lens effective test aperture: f/14
Canon MP-E 65mm f/2.8 105x macro lens setup
MPE nominal test aperture: f/3.5
MPE effective aperture for this test: f/15.75
Camera: Sony 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 a stack of images was made with 2 micron steps, and was repeated 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.
Click on the image below for a 2500 px sample from the 4/28.
100% crops from center and upper right corner area.
Componon 4/28 + 5.6/100 at f4 center
Canon MP-E 65 at f/3.5 center
Componon 4/28 + 5.6/100 at f4 corner
Canon MP-E 65 at f/3.5 corner
In the center the Canon's effective f/16 results in some softening and the CAs level is higher. In the corners the results are the similar. The 4/28 shows some pink lateral CAs, the MPE shows some green CAs in the same area.
With a good tube lens the CPN 4/28 corners would be be similar to the center with less CAs.
Questions or comments, post them below.
Thanks,
Robert
