Category Archives: Still photography

Lenovo puts malware on own systems that breaks HTTPS security

Read for the details: Lenovo Is Breaking HTTPS Security on its Recent Laptops | Electronic Frontier Foundation.

This is a very serious security vulnerability and Lenovo still has no fix to ensure that https is secure.

This is of interest to photographers and video shooters as the Lenovo Y50 notebook provides a 4K display screen, making it a popular choice among the photography and video community.

Brian May launches stereoscopy web site section

Brian’s Soapbox January 2015.

Brain May collects historic stereo photographs from the Victorian era and has also published a book on the subject.

If you do not recognize his name, he was also the lead guitarist for Queen and wrote a song you might have heard once or twice: We Will Rock You. After all that, he returned to graduate school to complete his doctorate in astrophysics.

 

Using a c-mount lens on a Nikon 1 J2 camera

The Nikon 1 cameras – J1, J2, J3, J4, V1, V2, and V3 – use a “1 inch” sensor that is about the same size as “Super 16mm” film. The small’ish sensor is ideal for working with old 16mm lenses (I have one) or with various c-mount lenses. Ideally, the c-mount lens should provide a “1 inch” coverage. However, the photos below were shot using a Tamron 4-12mm f/1.2 lens having a 1/2 inch coverage. Except when zoomed in, in which case it covers the full frame with a very tiny amount of vignetting.
These macro photos amazed me – shot on an inexpensive Nikon 1 J2 with a CCTV c-mount lens! You can click on the photos for larger version, although these were uploaded at about half the horizontal resolution. The extremely narrow depth of field is pretty neat for a small sensor camera using an inexpensive wide angle lens!
The c-mount lenses I have used are often quite soft when the aperture is fully opened. Stopping the aperture down a bit improves sharpness. They also tend to have softness in the corners, or vignetting. This particular lens is very good for these close macro shots – the edge softness is obviously not a problem as it is supposed to be out of focus! But I would not recommend this lens for general purpose shooting of non-close subjects. I also have a Computer 12.5-75mm f/1.2 lens. This is useful mostly in full zoom (75mm end) but at f/1.2 it is very soft. Stopping it down to f/2 to f/4 greatly improves the image quality – and with the telephoto effect, does a good job for creating certain types of narrow depth of field. I would not use it as a general purpose lens, however.
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Using old camera lenses on micro four thirds cameras

Not that long ago, I used some old Minolta film cameras. These cameras used lenses with the Minolta MC/MD mounting system and I have several old lenses that can be used on micro four thirds cameras with an appropriate adapter.
Here’s my informal judgement as to work works well and what does not when using these old lenses on modern micro four thirds cameras. All of my tests were done on my Lumix GH-2, shooting JPEG images and evaluating the JPEGs as they came straight out of the camera. I did not do any tests in RAW mode.
Minolta 50mm prime f/1.4

  • f/1.4 – At f/1.4, this lens is soft, almost fuzzy, and with low contrast. Not recommended at f/1.4
  • f/2.0 – At f/2.0, this lens is clean with good contrast. I would rate this excellent for my own purposes at f/2.0 and above.

Minolta 50mm prime f/1.7

  • f/1.7 – At f/1.7, this lens is also very soft.
  • f/2.8 – I rate this aperture as “pleasant”. Its not really soft but its not quite a sharp either – but overall provides a pleasing, smooth quality to the image, yet with a very nice narrow depth of field.
  • f/4 – At f/4.0 the lens becomes very sharp.

Sigma 28mm prime f/2.8

  • This lens just does not work well at all until probably f/4, then its fine. The lens is useful, however, since it is a macro focus lens. The 28mm works like a 56 mm full frame equivalent lens on the micro four thirds format – but focuses down to about two inches (5 cm)!

Sigma 28-70mm UC Zoom f/2.8

  • f/2.8 – At both the 28 and 70mm zoom settings (56 and 140mm FF equivalent on m43ds) the lens is noticeably soft, probably better at the 70mm end than the 28mm end.
  • f/4 – At f/4 and above the images are excellent.

This Sigma 28-70mm lens is probably one of my favorite lenses on my Lumix GH2. Its great for shooting when I want a narrow depth of field, but provides excellent sharpness and contrast.
Other Lenses
Another popular old lens is most any Canon FD glass. I have not tested these but the reviews I have read of Canon FD lenses similar to those above, also perform similarly – such as the Canon FD f/1.4 lens being soft at f/1.4 but nicely sharp by f/2. These can be found on eBay for $30 to $70, sometimes including the m43 adapter ring. Older Nikon lens are also excellent and popular and available used.
Keep in mind that to use an old lens you need to ensure your camera can operate with a “no electronics” lens. The Lumix GH-2, for example, has a menu setting to let the camera operate even if “no lens is attached”.  I use this setting and then put the camera in “A” Aperture mode, and set the aperture and focus manually. My Nikon 1 camera only works in “M” mode when a non-Nikkor lens is attached – this works, but is not as convenient as using the “A” mode and letting the camera meter and choose a shutter speed for me.
Newer lens systems, like the Canon EF series can also be made to work but with limitations – these lenses do not have an aperture ring and the lens, by default, will also be in the wide open aperture setting. There is a trick to get around this but its cumbersome – mount the lens on an actual Canon camera, set the aperture using the camera settings, remove the lens and put it on the m43d camera and it retains the aperture setting. But why go to that trouble? Better off getting an original all manual lens like the Canon FD.
Both of these two photos were taken with the Lumix GH-2 and the Sigma 28-70mm f/2.8 lens at f/2.8 to create the narrow depth of field look. You can click on these images – twice, in fact – to zoom in to larger versions. Both are reduced in size and compression from the originals, however.
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