Open

by damned truths

submit your photo


Hall of Fame
View past winners from this year

Please participate in Meta
and help us grow.

54,713 reputation
8107250
bio website jonrista.com
location Aurora, CO
age 35
visits member for 4 years, 5 months
seen Dec 15 at 22:21

I am a relatively new photographer, having been at if for only a few years. I chose Canon gear when I finally took the plunge into DSLR. I am an avid hobbyist now, and love everything about photography, from the gear, to the science, to the art. I spent years reading about the technology and photography theory, so I am very well versed in the technical aspects of photography. My artistic skills are moderate, but improving. You can see my work @ the following sites:

My interests lie primarily in nature photography:

  • Birds
    • Songbird Setups
    • Shore Birds & Waders
    • Raptors
    • All others
  • Astrophotography
    • Moon
    • Wide Field
    • Deep Sky
  • Landscapes
  • Wildlife
  • Floral Macro
  • Insect Macro
  • Abstract

I currently use the following gear:

  • Cameras
    • Canon EOS 7D
    • Canon EOS 450D (Rebel XSi)
  • Lenses
    • EF 16-35 f/2.8 USM L Wide
    • EF 50mm f/1.4 USM
    • EF 100mm f/2.8 USM Macro
    • EF 100-400mm f/3.5-5.6 IS USM L Zoom
    • EF 600mm f/4 L IS II
    • Canon EF 1.4x TC III
    • Kenko 1.4x Teleplus Pro 300 DGX
    • Periodic Rentals:
      • EF 300mm f/2.8 L IS II
      • EF 500mm f/4 L IS II
      • Canon EF 2x TC III
  • Filters
    • Lee Foundation Kit (x2) + Tandem Adapter
    • Lee .3/.6 ND
    • Lee .3/.6/.9 Soft Grad ND
    • Lee .3/.6/.9 Hard Grad ND
    • Lee CPL
  • Tripod
    • Gitzo Systematic GT3532LS 3S. Series 3 Tripod
    • Jobu Pro 2 Gimbal
    • Gitzo Mountaineer GT0541 4S. Series.0 Tripod
    • Gitzo GH1780QR Series.1 Mag. Center Ball Head

May
28
comment What's the difference between colour space and bit depth?
From a numeric standpoint, yes. From a rendering standpoint, it depends on the color space. ;)
May
28
comment Why image at 400mm is LARGER THAN DOUBLE of image at 200mm? (according to lens formula)
The subject area increases by 2.25x (600mm shrinks the FoV in both width AND height), linear scaling is 1.5x. Think about it, though...the increase in area is more relevant, as it means you have that many more pixels on your subject. Pixels on subject is really where IQ comes from...the more pixels you can get on your subject, the sharper, less noisy, etc. for any given output magnification.
May
27
answered Why image at 400mm is LARGER THAN DOUBLE of image at 200mm? (according to lens formula)
May
27
answered Setting white balance for raw image from Canon S100 using Lighroom failed to work well
May
27
comment What's the difference between colour space and bit depth?
@Jason: The term "extent" works for three-dimensional spatial objects. It does not mean just a two-dimensional extent such as a triangle superimposed on top of the full brightness/saturation plot of Lab space. Extent means the entire extent of the color space, in all three dimensions, regardless of the actual shape that extent takes. I'd also state that sRGB, AdobeRGB, etc. are color spaces, while RGB, YUV, HSL, CMYK, etc. are color models, not color spaces. Color spaces ARE 3D, but generally they have odd mushed diamond shapes, they are never cylindrical or cubic.
May
26
comment Human perception in color mixing
Aye, you can perform gamma-adjusted blending, however I am not sure that really takes into account the differences in the way human vision "averages" or "interpolates" information. Gamma-adjusted algorithms simply aim to work within the specs of the device, but they are still the same fundamental algorithms.
May
26
comment Is the format for the distortion and chromatic aberration correction of µ4/3 lenses documented?
@bronger: And I quote the OP: Is this format documented anywhere (either officially **or through reverse-engineering**)? The OP specifically stated that reverse-engineering was a perfectly viable option, so I still fail to see why your making your argument, and still believe your downvote was unwarranted.
May
26
comment Human perception in color mixing
@tomp: I'm sure some research has been done. I know that tools like Photoshop, as well as more specialized tools like PixInsight (astrophotography editing tool) allow a considerable amount of their algorithms to be executed within Lab space. Someone must have researched the hows and whys to be able to make that possible.
May
26
comment What's the difference between colour space and bit depth?
@BBking: That isn't quite correct. The two are not linked in that way. The building size doesn't have to change if you move to 16 steps, because you can make the steps be closer together than when you have only 8 steps. Bit depth is the closeness of the steps, while color space is the size of the building. I've added an answer that may help.
May
26
answered What's the difference between colour space and bit depth?
May
26
comment Human perception in color mixing
There is research in this area, from the standpoint of the human perception of color. That's all of CIE's work. There are decades of studies and mathematical modeling and refinement of models in CIE's body of work that covers human visual perception in quite a bit of detail. There is also some fairly extensive study of human color perception by other bodies as well, from medical institutions to universities. In terms of matching human visual perception to computer color models, some work has been done (i.e. RGB->XYZ->Lab transforms), but I myself kind of threaded the pieces together here.
May
25
comment UV Filter Coating
If it's dust on the filter, I'd just clean the filter. Pick up a pack of kimwipes and a soft brush (either camel hair or something synthetic like a lens pen). Brush off the filter, clean it with the kimwipe (dry, they work like magic, and don't worry about the rough feel, it's by design and WHY they work so well.) If that does not fix the problem, then it's probably a nick in the glass or coating, and you'll probably need to replace the filter to get rid of the problem.
May
25
revised Human perception in color mixing
added 2315 characters in body
May
25
answered UV Filter Coating
May
25
answered Human perception in color mixing
May
24
comment How to use TC's with Canon lenses
This question is pretty vague. If your just looking to know what TC to use to double your focal length, that is quite literally self explanatory. If your asking about something else, you need to be a lot clearer.
May
23
comment Aperture priority images are all severly underexposed
@Jon: Normally, that would be correct...however your situation is not normal. Your using a lens that does not communicate with the camera, which is forcing the camera to make incorrect assumptions about what settings IT should set to get a correct exposure. You NEVER get a correct exposure, as light changes or otherwise. Your solution is manual mode. Don't fear it...with a little practice, you'll be a wizard at changing settings on the fly as needed to get the right exposure.
May
23
comment Is the format for the distortion and chromatic aberration correction of µ4/3 lenses documented?
@bronger: Actually, it does answer the question, as best as was possible at the time. The OP asked for documentation, and indicated the goal was to ultimately implement lens correction functionality in OSS. The information I provided was the best information available FOUR YEARS ago. I think your downvote is unwarranted and your comment missed the point of the question.
May
23
awarded  Notable Question
May
22
comment How can an amateur print high gamut images?
Finally, papers that have a nice dMax and high L* very frequently achieve that via OBAs. OBAs can definitely improve your gamut, color reproduction, dynamic range, etc. Just beware that OBAs are uv-sensitive (they absorb UV then reflect it back at a lower energy), so they fade over time. If you want brilliant prints, especially brilliant matte prints, you SHOULD choose a paper with OBAs (Moab Lasal Photo Matte is a wonderful example), and you'll get some of the best gamut you can find. If you need "archival" longevity, then acid free natural fiber papers are usually best.