Posted: Thu Apr 20, 2023 10:43 am Post subject: Seagull SB-II 28mm F2 lens for Dongfeng missile |
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Tefolium wrote:
Recently, I found a industry camera named SB-408B made by Shanghai No.3 Camera Factory using a 28mm F2 lens.
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I ask a friend for help to buy it.
It has the same flange back as LTM but its mount is m32 × 1mm. And the frame size is 24mm × 24mm
So we thought it might be one of the lenses designed by Chinese Academy of Sciences in 1950s-1960s, because the first Chinese-designed Cine lens/Photography lens used a mount which is different to L39 but it seems that it has the same flange back as L39.
I found some catalogues.
It is Seagull SB-II.
They say that its POV is 46° or 56°.
While 28mm cine lenses' POV is 52°.
So, it is not a s35 cine lens which was adapted to a industry camera.
And, Seagull's Military Industry History said:
It was a disposable TV lens designed in 1970.
It was designed for missile (Dongfeng-4 and Dongfeng-5, not the SLR).
Its frame size is designed as 18mm × 24mm.
The lenses were modified and used as industry lens soon after its design.
Seagull SB-II f28mm 1:2
Aperture: F2 - 8
Distance: 0.3m - infinity
Mount: M32 × 1mm
Flange distance: 28.8mm
My friend Ale used Nikon Z7 to test the lens.
It cover a Φ30mm round.
F2
F4
F2
F4
F2
F4
F2 front
F2 back
By the way, SB6 (f58mm 1:2)=HAIOU-64/LAODONG, M42 × 1mm(36.5mm flange back) version. SB3(f50mm 1:1.4) should be Red flag 50mm 1:1.4 lenses‘ M42 × 1mm(36.5mm flange back) version. |