Are there any "speed-booster" adapter for CCTV cameras? - Page 1
Forum section: electronics / projects

author: Logan
author_rank: Frequent Contributor
timestamp: January 13, 2022, 03:33:54 pm
content: Hi.I wonder if there are any speed-booster adapter that allow 1-inch, 4/3-inch, or even APS, 35mm format photography lens to be used with 1/2 or 1/3 sensor c/cs-mount cameras, that will boost iris for several steps!If no off-the-shelf product, is there a rather easy way to make one?Related link:https://www.dpreview.com/articles/2667195592/first-impressions-metabones-speed-boosterThanks.

author: jonovid
author_rank: Super Contributor
timestamp: January 13, 2022, 04:12:17 pm
content: The Speed Booster looks like clever marketinganything is possible with lens adapters if pay big $ or just get a better CCTV camera.I did try to cobble together cctv sensor and 35mm pathology lenses but the results were disappointing.depth of field missmachs edge of the frame had blurryness.

author: magic
author_rank: Super Contributor
timestamp: January 14, 2022, 11:51:46 pm
content: AFAIK those "speed boosters" only take you to about f/1 at best, so a 2x booster on f/1 will bring no improvement and so will a 4x booster on f/2 and so on. You are asking for the impossibleGet an ordinary f/2 CCTV lens and be done with it. If you want faster, I think they make them down to f/1.4 or maybe f/1 too. I doubt that assembling such a lens from two pieces would be any cheaper.And yeah, possibly not the best choice of a forum for this topic

author: Logan
author_rank: Frequent Contributor
timestamp: January 15, 2022, 09:04:38 am
content: Thank you for replying.Quote from: magic on January 14, 2022, 11:51:46 pmWhy?Quote from: magic on January 14, 2022, 11:51:46 pmF number is not linear:https://en.wikipedia.org/wiki/F-numberThanks.

author: magic
author_rank: Super Contributor
timestamp: January 15, 2022, 11:43:50 am
content: If you could build an f/1 lens and make it f/0.5 with a speed booster than you could also build an f/0.5 lens by combining the two optics in one barrel. And f/0.5 photographic lenses generally aren't a thing for some reason. Size, complexity and price skyrockets near f/1.As for what I understand the underlying problem to be, it's that you have increasingly wide and overlapping pencils of light which need to be precisely focused on different points closely spaced at a close distance, and conversely, each part of any optical surface needs to correctly handle increasingly many pencils passing through it in different directions and all sorts of aberrations come out and the design becomes a nightmare. But I'm not a lens designer, so

author: BradC
author_rank: Super Contributor
timestamp: January 15, 2022, 12:48:19 pm
content: Quote from: magic on January 15, 2022, 11:43:50 amI have a lovely f/0.8 50mm fixed lens coupled with a 1" imager (1920x1080) at home that I use to demonstrate what actual "low light performance" is. It's not unlike a canon and the light performance is quite something else. The lens and camera was originally > $3k however and the manufacturer went under several years ago.The real question is "what are you trying to achieve?".

author: CaptDon
author_rank: Super Contributor
timestamp: January 15, 2022, 03:55:35 pm
content: How about an image intensifier coupled to your camera input. Sounds like that is where you are headed. Since it is CCTV it isn't likely you can increase exposure time. There was a trick for still frame years ago with vidicon cameras. The scanning was stopped, the shutter was opened then fully closed to create a long exposure time. Then the vidicon was scanned for one full frame (usually a non-interlaced scan) and the single video frame was recorded for a 'still store' video frame. You could not have motion in the frame or it would smear. It was possible to get nearly starlight night vision however. You couldn't really see who stole the truck, but you could pin-point when it went missing shooting at 1fps in near total darkness with an undetectable camera.

author: Someone
author_rank: Super Contributor
timestamp: January 15, 2022, 09:55:39 pm
content: Quote from: magic on January 15, 2022, 11:43:50 amWith so much momentum behind the SLR lens formats, they have "defined" photography lenses (and optical standards for cinema cameras similarly mandated space for a viewfinder). Take EF mount with its larger than average internal diameter of 54mm but a minimum clearance from sensor/film plane to optics of 38mm, if you've packed 36x24mm a full frame sensor in there then you cannot get f/1.0 performance uniformly across the frame, hence the heavy vignetting on the Canon 50mm f/1.0 L:https://www.kenrockwell.com/canon/lenses/50mm-f1.htmFor EF mount absolute peak would be f/0.7 in the centre of the sensor plane.Mirrorless is still seen as an inferior choice in photography for some reason (but well accepted and largely preferred in video/cinema).