Saturday, November 12, 2022

Rapid COVID Test 2022

Roche Pilot
Roche Pilot home COVID test

Previous post: Rapid COVID Test

Roche Pilot at home COVID test at CVS

  • Previously available in Europe and U.S. government distribution.
  • Clinical study results [excellent]: 
    • False-negative rate of 6.8%.
    • False-positive rate of 0%.
  • CVS to stock it.
  • New #1 recommendation, dropping ACON FlowFlex to (close) #2.


Sunday, March 27, 2022

Lumix DMC-FZ2500 Video

Lumix DNC-FZ2500
Lumix DMC-FZ2500
The Lumix DMC-FZ2500 is great for sports action video!

Panasonic makes two great large (1") sensor Lumix bridge cameras with excellent Leica-branded superzoom lenses:

  • DMC-FZ1000: great stills camera that also does very good video.
  • DMC-FZ2500: great video camera that also does very good stills.
While the FZ2500 has a rich and powerful video feature set, its still image heritage makes the optimum video setup a bit tricky. For example, the viewfinder display in "S" Creative Video Mode shows the shutter speed but not the aperture. (Go figure.)

Action Sports Recommendations

  • MP4 LPCM FHD 50M 60p
    • Recording Format. Choose either MP4 LPCM or MOV (which are essentially identical) based on your own workflow. If in doubt, choose MP4 LPCM.
    • Frame Rate. For action video, 60 fps (frames per second) gives smoother results than lower frame rates. That limits resolution to 1080p Full HD (FHD, not 4K), but that's usually sufficient for most purposes.
    • Bitrate. 100M (Mbps) gives highest quality, but 50M is probably fine if you won't be doing heavy post-processing. 200M ALL-I is not recommended because quality is actually lower than 100M. 
  • Mode. For smooth video, use a shutter speed twice the frame rate, so with 60 fps, use a shutter speed of 1/125 sec in Shutter Priority (S) mode.
  • Aperture. Unfortunately, the FZ2500 lens suffers increasingly from diffraction softness at apertures smaller than f/5.6, so aperture should be no smaller than f/8.
  • ND. Thankfully, the FZ2500 has built-in ND (neutral density) filters that can be used to keep the aperture large enough for sharp images. In general, 1/4 works well in outdoor sunlight with 1/125 sec shutter speed. Unfortunately, the viewfinder does not display the aperture in "S" Creative Video Mode, so either shoot video in Shutter Priority (S) mode, or switch temporarily to S mode to check the aperture set by the camera.
  • Sample video with these settings: SailGP Practice, San Francisco Bay, 25 Mar 2022 - YouTube
  • Stills. Shutter speed of 1/125 sec is often too slow for action sports. For different settings:
    • Use Shutter Priority (S) with ND on for video.
    • Use Aperture Priority (A) with ND off for stills, with lens wide open
    • Unfortunately, unlike FZ1000, FZ2500 has only one Mode dial setting for Custom mode, so switching between Custom modes is a clumsy menu operation.

SanDisk Extreme PRO

Notes

  1. Except as noted, default settings are recommended.
  2. Continuous Autofocus (AFC) works well in tracking moving subjects.
  3. i.Dynamic Auto can help on dynamic range.
  4. Diffraction Compensation is just extra sharpening and should not be used.
  5. AF/AE Lock can help when lighting is variable.

Tips

Happy shooting!