For The Pixel-peeping Insomniac

Some may realize how tele-centric I am with my lenses, so here’s a shootout of 7 lenses that can reach 210mm either by themselves or with the aid of teleconverters. All shot with the Sony A100 at F16, ISO Low-key 80 with flash on a certain morning of 20th September 2007.

Lenses involved, from right to left:

  1. Peleng 8mm F3.5 circular fisheye (okay, it wasn’t included but it sneaked in because it thought it would look nice in the picture)
  2. Sony 18-70mm F3.5-5.6 DT (sold)
  3. Minolta 28-80mm F3.5-5.6 Silver (sold)
  4. Vivitar Series 1 28-105mm F2.8-3.8
  5. Cosina 70-210mm F2.8-4 Macro
  6. Minolta 70-210mm F4 “beercan”
  7. Tamron 200-400mm F5.6

The battered, misaligned elements, melted rubber Sigma 70-210mm F4-5.6 opted to skip the photo shoot.

Sony 18-70mm F3.5-5.6 DT with Tamron 1.4x and Kenko 2x. 1/60s.

Minolta 28-80mm F3.5-5.6 with Tamron 1.4x and Kenko 2x. 1/100s.

Vivitar Series 1 28-105mm F2.8-3.8 with Kenko 2x. 1/125s.

Sigma 70-210mm F4-5.6. 1/125s. Note that this is a battered lens found in a box of junk, with misaligned elements that give all sorts of aberrations.

Minolta 70-210mm F4 “beercan”. 1/125s.

Cosina 70-210mm F2.8-4 Macro. 1/125s.

Tamron 200-400mm F5.6. 1/125s. The minimum focus distance is 2.5 meters, far longer than my room, thus the objects are out of focus.

Tamron 200-400mm F5.6 at F32 1/125s. Still not quite in focus.

Why do the lenses vary so much in color and actual focal length?

  1. Focal length changes with focus distance. The closer the focus, the shorter the focal length, especially on zoom lenses.
  2. Slower shutter speeds let in more ambient light; in the Sony 18-70mm it looks more blue because more flourescent light has come in.

Also, the Tamron 1.4x teleconverter is a wee bit soft. Gotta get a newer one… but this is a nice softener for portraits.

I particularly like the Vivitar Series 1 28-105mm’s color. The Tamron 200-400mm seems rather blue while the F32 shot kills off the flourescent light’s blue.

To be fair, I should shoot with the lenses focused at infinity, plus most lenses (except portrait lenses and macros) are optimized for sharpness at infinity. I conducted this test past midnight, like about every other photographic test that I do, or I could’ve headed out to the hills near by house.

6 thoughts on “For The Pixel-peeping Insomniac

  1. ShaolinTiger Post author

    Would have been fairer if you’d used M fixed the shutter as well as the aperture and used a static WB preset. That’d give a better comparison..with variable shutter speeds and AWB you can’t really compare anything other than how inconsistent your camera is.

  2. Albert Ng Post author

    Ah yes, my bad. They were all in AWB, Aperture Priority. It’s one of those things you realize that you’ve overlooked… much later. Though, when the camera has flash attached in AWB, it presets to Flash WB. It probably would’ve helped as well to have turned off the ambient lights just before shooting.

  3. Albert Ng Post author

    I just tried shooting the same backdrop with the same flourescent light at 1/60s ISO200 F9. The frame was black, the histograms said so and the entire frame blinked black. Ironically, that means that ambient light was killed off early, so I do not understand the variance in color for the Tamron 200-400mm F5.6 samples… unless there is variance in flash color based on intensity, which is what some people reckon is the method that the auto-WB Sony F42 flash will use. However, flash always fires at the same power but cuts off quicker or slower so that doesn’t validate that theory, either!

  4. ShaolinTiger Post author

    Yah seen as though are using Av different lenses meter the same scene differently, still an interesting comparison.

    I wonder if your flash has inconsistent light temperature too? Or perhaps slight movements make the light bounce of different coloured parts of your room?

  5. Albert Ng Post author

    It’s said that Canon lenses have wildly varying colors while Minolta lenses pride in being consistent – I don’t know about Nikkor lenses though, perhaps you could find out. The Minolta 28-80mm might be bluer due to the teleconverters. Yet another variable!

    I tested the flash with 1/1 power at F8, 1/4 power at F4, 1/16 power at F2. Same temperature for all three shots! If I remember I shot the flash directly forward.

    Thus, it could be attributed to the lens, but it doesn’t explain the Tamron 200-400mm results still. Will research further the next time I do more nocturnal tests!


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