Latest or all posts or last 15, 30, 90 or 180 days.
877-865-7002
Today’s Deal Zone Items... Handpicked deals...
$300 $175
SAVE $125

$999 $879
SAVE $120

$348 $298
SAVE $50

$400 $310
SAVE $90

$2098 $1298
SAVE $800

$1499 $1149
SAVE $350

$322 $242
SAVE $80

$1499 $1149
SAVE $350

$1299 $949
SAVE $350

$330 $330
SAVE $click

$498 $498
SAVE $click

$180 $140
SAVE $40

$1299 $949
SAVE $350

$500 $500
SAVE $click

$180 $156
SAVE $24

$130 $100
SAVE $30

$2997 $2997
SAVE $click

$3498 $2998
SAVE $500

$370 $370
SAVE $click

$4899 $4899
SAVE $click

$1000 $1000
SAVE $click

$1699 $1149
SAVE $550

$280 $230
SAVE $50

$1899 $1499
SAVE $400

$4499 $3499
SAVE $1000

$2198 $1998
SAVE $200

$3998 $3498
SAVE $500

$1799 $1699
SAVE $100

$18599 $16599
SAVE $2000

$1149 $849
SAVE $300

$650 $450
SAVE $200

$199 $119
SAVE $80

$280 $200
SAVE $80

$1399 $1049
SAVE $350

$1199 $779
SAVE $420

$250 $220
SAVE $30

$1699 $1149
SAVE $550

$195 $125
SAVE $70

$79 $49
SAVE $30

$120 $30
SAVE $90

$198 $148
SAVE $50

$3899 $1499
SAVE $2400

$2999 $1999
SAVE $1000

$1699 $849
SAVE $850

$1698 $1198
SAVE $500

$1149 $849
SAVE $300

$1399 $1049
SAVE $350

$1498 $998
SAVE $500

$2797 $2497
SAVE $300

$280 $230
SAVE $50

$899 $549
SAVE $350

$420 $170
SAVE $250

$1699 $1149
SAVE $550

$3397 $3097
SAVE $300

Upgrade the memory of your 2020 iMac up to 128GB
OWC Accelsior 4M2 PCIe SSD
6000 MB/sec!
Mac or PC.


Ideal for Lightroom, Photoshop, video.
Capacity up to 16TB!

Sony A7R: Sensor Glass Thickness, Ray Angle and Image Degradation: Kolarivision Modification

Just arrived from Kolarivision is a Sony A7R in which the sensor cover glass has been replaced with significantly less thick glass. See A Thinner Sensor Stack at LensRentals.com for some background info.

I’ll be shooting this modified camera this weekend, with a report to follow.

The thick sensor cover glass has meant that rangefinder lenses (Leica M, Zeiss ZM, Voigtlander) have had severely degraded performance outside (roughly) the central 1/2 of the frame, due to ray angle, as reported on for years, and documented extensively on this site.

General issues from sensor glass

From Astigmatism and Digital Sensors in Making Sharp Images. Here, “glass plate” means the sensor cover glass.

  • The main impact of an added glass plate to more oblique rays is the introduction of severe astigmatism in the imaging field. The tangential image surface is shifted forward while the sagittal is minimally affected.
  • Astigmatism means a highly non-symmetric point image, not just being softer but killing the similarity between object and image structures. Often the blur resembles the effects of motion blur which can produce “cross-eyed” or double-image bokeh (very unappealing to the eye, downright ugly).
  • On axis the added plate changes the correction towards ‘spherically overcorrected’ when the lens speed is fast, which produces less pleasing background bokeh.
  • In general the sensor cover glass plate shifts the position of the image by about a third of the plate thickness – and that is the point where the dispersion of the plate itself comes into the game, since in the imaging field with oblique rays a longitudinal shift is always connected to a lateral shift. This effect modifies the lateral chromatic correction of the lens.

See also

OWC Thunderblade Thunderbolt 3 SSD

Blazing fast, up to 16TB.

YEE HAH!



√ No more slow and noisy hard drives!
Sigma I-Series lenses NEW!

24/3.5, 35/2, 65/2 focals

Sony mirrorless or Leica L
OWC Envoy Pro EX SSD
Blazingly fast Thunderbolt 3 SSD!

Up to 4TB capacity, USB-C compatible.

USB-C model also available


Great for travel or for desktop!
OWC Envoy Express

World’s first Thunderbolt 3 M.2 NVME SSD enclosure.

Super fast, bus-powered, 3.3 oz, DIY easy, rugged and compact!


See also OWC Express 4M2
√ No more slow and noisy hard drives!

Deals Updated Daily at B&H Photo
View all handpicked deals...

Apple 13.3" MacBook Air with Retina Display (Early 2020, Space Gray)
$999 $879
SAVE $120

diglloyd Inc. | FTC Disclosure | PRIVACY POLICY | Trademarks | Terms of Use
Contact | About Lloyd Chambers | Consulting | Photo Tours
RSS Feeds | Twitter
Copyright © 2020 diglloyd Inc, all rights reserved.