Time to be with your loved ones

Time to be with loved ones

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51,858 reputation
799235
bio website jonrista.com
location Aurora, CO
age 34
visits member for 3 years, 9 months
seen 9 hours ago

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

Mar
15
comment Why does my Canon 7D get blurry pictures with a 70-200mm f/2.8 IS (series 1)?
Maybe. What you see on live view is a form of JPEG encoding...and depending on how large the focus error might be, you may or may not be able to tell with just live view. I still think that using something like Reikan FoCal or LensAlign would still be best to determine if there is an actual error in the lens or if it just needed microadjustment. It is practically impossible to tell a difference, visually, with AFMA between 10-12 steps with live view. That's more than half the range of AFMA, but focus error is usually very, very slight.
Mar
14
comment Why does my Canon 7D get blurry pictures with a 70-200mm f/2.8 IS (series 1)?
AFMA isn't about the lens, it's about the lens+camera combo, and it specifically adjusts PDAF behavior. Testing CDAF won't really tell you anything about whether you need to AFMA, because it's testing the wrong AF system. All that AFMA does is set a digital shift value that the cameras AF drive firmware uses to direct the lens when focusing. If you were off by -10 AFMA steps, when the camera tells the lens to focus, it tells it to focus by the amount the PDAF sensor detected, minus the AFMA adjustment.
Mar
11
comment What is bokeh, exactly?
+1! As always, great answer and wonderful diagram!
Mar
2
comment Does this appear correct? Comparison of PSD & TIFF file sizes when using adjustment layers.
My guess is that Adobe is able to optimize saving adjustment layers in PSD when the mask has not been modified. That is not possible with TIFF, as TIFF is a general purpose format that must be compatible with other programs, where as PSD is a format specific to Photoshop. There is still going to be important metadata and state data that has to be saved for each adjustment layer, but the layer itself probably does not require the mask to be saved in photoshop unless it has been modified.
Mar
2
comment Why do my tiff files balloon in size when saved with 1 adjustment layer?
Adjustment layers all have a mask. The mask by default is fully white, however it is the same dimensions and bit depth as the rest of the image. So in addition to the "final result" image that is saved, you have the original layer as well as the adjustment layers mask. On top of the bitmap data, you have all the various photoshop active state and adjustment layer settings that need to be saved as well, which would account for the additional overhead.
Feb
28
awarded  Good Answer
Feb
27
comment Why doesn't my fisheye adapter gives fisheye distorsion on my APS-C DSLR?
Since you are using an adapter ring to adapt the fisheye (from I presume 62mm) to the lens (42mm), you are effectively cutting out a LOT of the highly oblique angle light. A fisheye lens is designed to gather rays of light from up to 180°, and focus those onto the sensor. Since you are downgrading your fisheye element to a much smaller diameter, any part of the fisheye that extends beyond the filter ring of your lens is effectively wasted FoV. You should be using a fisheye element that is specifically designed for 42mm.
Feb
27
reviewed Reject suggested edit on Why does a reverse lens act like a macro lens?
Feb
27
comment How to have colors in Milky-way?
@drfrogsplat: It really doesn't matter the generation of the sensor. Any technology that can be applied to smaller pixels can be applied to larger pixels, so there will NEVER be an SNR advantage to smaller pixels in the grand scheme of things. Greater area per pixel, stronger signal, greater SNR, lower noise. That's just the fact of things, at least when it comes to astrophotography. Regular photography may be different, as what often matters most is total light per sensor area, rather than per pixel area. In AP, the total light per pixel is really the most important thing.
Feb
25
awarded  Nice Answer
Feb
25
answered How relevant are the DxOMark scores and tests?
Feb
18
comment What is the use of printer profiles when softproofing?
They will only be the closest perceptually accurate matches. Finally, note that you can only use one ICM engine at a time. If you use Photoshop's ICM to process the image, then send it to the printer and let the printer do it's own ICM on top of what Photoshop does, then your bound to get some radically screwed up color. If you want an entirely color managed workflow, you need to make sure that there is only one color manager. Photoshop uses it's own. Windows offers an ICM engine as well (and Photoshop can be configured to use it.) You DISABLE printer managed if you print from Photoshop ICM.
Feb
18
comment What is the use of printer profiles when softproofing?
There are no inversions of anything in this process. There is only translation. The divergence of color from screen to print is not massive, there is no purple to yellow inversion mapping that goes on. There is simply a vibrant image yellow to duller print yellow. But both devices still have "yellow". You don't invert, you map. The input yellow from the image must be mapped to a color coordinate that results in the appropriate combination of inks being used to produce the closes perceptually accurate yellow in print on the chosen paper type. They will not be 100% exact matches.
Feb
18
comment What is the use of printer profiles when softproofing?
Once a perceptually-accurate translation for a chosen rendering intent (perceptual, saturation, relative, absolute) is performed, the new color coordinates in L*a*b* are converted back into XYZ, and from XYZ back into RGB. That RGB image is then sent to the printers rasterizer, which converts the RGB image into a dithered CMYK (or, in the case of say a Canon proGraf, CMCpMpYGRBkGr) image that directly conforms to the printers ink selections, print head design, and supported droplet layouts. The rasterized image is what is actually printed.
Feb
18
comment What is the use of printer profiles when softproofing?
Once you have a profile, then all you need to do is run a translation from a source to a destination. The source must have it's ICC profile, and the destination must also have its own ICC profile. The process of translating color from the source to the destination involves converting RGB color into XYZ color in 3D color space. XYZ color is then converted into L*a*b* space, which models human color perception in 3D. All color space translations occur in L*a*b*, so that they are perceptually accurate, using the necessary mapping information in the Image and Printer ICC profiles.
Feb
18
comment What is the use of printer profiles when softproofing?
Your misunderstanding what an ICC profile contains. An ICC profile contains a description of how a given device renders color, and how those colors relate to human visual perception. There is no inversion or anything like that going on. When you profile a printer, you profile a printer. Profiling has ZERO relationship to any other "ICC profile"...note the words here: Profiling vs. profile. Profiling is the process of generating a device color description. Ac ICC profile is what that description is stored within. The ICC does not do the profiling, it is the result if profiling.
Feb
18
comment What is the use of printer profiles when softproofing?
I'm not exactly sure what your trying to say. Printers don't invert colors. Yellow is still yellow, it's just that for yellow in print to be perceived as yellow by human eyes under standard illuminants, it needs to look a little different. There is a slight divergence, but no inversion. There really isn't anything complicated here. If you print, ICM does Image(sRGB) -> Printer(PrinterAndPaperICC). If you are soft proofing, ICM does Image(sRGB) -> Printer(PrinterAndPaperICC) -> Screen(ScreenICC). That's all were talking about here. ICC profiles describe devices, ICM translates.
Feb
17
comment What is the use of printer profiles when softproofing?
As for soft proofing, I'm not sure what you think it is. Soft proofing, from an ICM standpoint, is simply rendering to screen what the ICC profile of the printer generates. So, instead of rendering Image(sRGB) -> Screen(ScreenICC), you do Image(sRGB) -> Printer(EpsonHahnemuhlePhotoRagNaturalICC) -> Screen(ScreenICC). By first mapping to the printer space, what you see on screen is based on how the printer would render the image. There for, you can "soft proof" your image, and make sure that it will print correctly, with the right tonality, shadow detail, highlight detail, etc. on that paper.
Feb
17
comment What is the use of printer profiles when softproofing?
...print space. So, a vector, from pure green to the closest possible match in printer space is determined through the process of profiling, and that divergence is saved in the ICC profile. This is actually done for all colors through a fairly complex mathematical modeling process, and the model is what is stored in an ICC profile, so it isn't as though every possible individual color is mapped.
Feb
17
comment What is the use of printer profiles when softproofing?
The ICC profile simply contains the information necessary to translate color from a source context or to a destination context. Color is three dimensional: You have the color plane in x and y, produced by a 360° plot from red through orange, yellow, green, blue, purple and magenta. Intensity is the z axis, towards 0 is black, towards 1 is white, and in between you have all the various tones of each color. An ICC profile is simply a mapping of divergences of color for a given device, in this 3D space. A "true" pure green, as described in Lab space, would actually be some other color in...