Page 2 of 2 FirstFirst 12
Results 16 to 27 of 27

Thread: On Ura-Dashi Failure and Success

  1. #16
    Join Date
    Mar 2006
    Location
    Austin Texas
    Posts
    1,957
    Follow up to anyone that can help with my above question - I believe that I am looking more for camera info rather than "how to attach" info. My older Canon does not seem to be able to get that close and stay focused. Is there some trick to it or is it just buying a better, more close up type photo suited camera.
    David

  2. #17
    Join Date
    Aug 2013
    Location
    Princeton, NJ
    Posts
    7,254
    Blog Entries
    7
    Quote Originally Posted by David Eisenhauer View Post
    OK, completely off topic Brian - how in the world do you post these very large, very close up photos? Please don't tell me "Google is your best friend", but perhaps a very short explanation that can point me in the proper search direction would be possible.
    Believe it or not those are IPhone photos. I'm very particular about lighting and it helps a weak camera tremendously. My blog is my host and they host full size but of course I have to pay for the storage.
    Bumbling forward into the unknown.

  3. #18
    Join Date
    Dec 2015
    Location
    Dublin, CA
    Posts
    4,119
    Quote Originally Posted by Brian Holcombe View Post
    Believe it or not those are IPhone photos. I'm very particular about lighting and it helps a weak camera tremendously. My blog is my host and they host full size but of course I have to pay for the storage.
    Indeed.

    Phones unavoidably have very small sensors, but the modern higher-end ones (and all iPhones are fairly high-end) have good optics, low-noise electronics, and very clever image-processing. If you have enough light to allow the camera to operate at or near its base ISO and if the scene contrast (difference between lightest and darkest tones) is reasonably low then they do pretty well.

    Each pixel in a state of the art SLR can record something like 12 stops (a 4000:1 ratio) from saturation to the noise floor at base ISO, and they do even better than that if you look at visually relevant areas instead of individual pixels. No phone can come remotely close to that sort of performance because they simply don't scoop up enough photons, but as long as you don't ask a phone to do stuff that needs that sort of performance it can do remarkably well.

    Background: I worked in image processing for a fair while in between ME and CS careers. Imaging was my bridge between the two. I've also shot quite a bit with everything from phones to 8x10" view cameras (the kind where you put a hood over your head and stare at an upside-down and backwards image on ground glass).
    Last edited by Patrick Chase; 01-22-2017 at 12:41 AM.

  4. #19
    Join Date
    Mar 2015
    Location
    SE Michigan
    Posts
    3,222
    Aw..now you've made it too pretty to use. Very nice restoration though.

  5. #20
    Join Date
    Aug 2013
    Location
    Princeton, NJ
    Posts
    7,254
    Blog Entries
    7
    Quote Originally Posted by Patrick Chase View Post
    Indeed.

    Phones unavoidably have very small sensors, but the modern higher-end ones (and all iPhones are fairly high-end) have good optics, low-noise electronics, and very clever image-processing. If you have enough light to allow the camera to operate at or near its base ISO and if the scene contrast (difference between lightest and darkest tones) is reasonably low then they do pretty well.

    Each pixel in a state of the art SLR can record something like 12 stops (a 4000:1 ratio) from saturation to the noise floor at base ISO, and they do even better than that if you look at visually relevant areas instead of individual pixels. No phone can come remotely close to that sort of performance because they simply don't scoop up enough photons, but as long as you don't ask a phone to do stuff that needs that sort of performance it can do remarkably well.

    Background: I worked in image processing for a fair while in between ME and CS careers. Imaging was my bridge between the two. I've also shot quite a bit with everything from phones to 8x10" view cameras (the kind were you put a hood over your head and stare at an upside-down and backwards image on ground glass).
    Exactly, I had a very frank conversation with an excellent photography equipment store owner who suggested do everything to make the job easy on the camera before upgrading the camera.

    For instance, I have one area of my shop that I use as a sort of photography spot. I painted the walls around it super white (BM color), added lighting including spot lighting, and I can get some pretty high quality shots out of the phone.

    I noticed I get the most realistic looking color range out of the wood when I'm placing it against a white background, so thats what I did. It also makes it easier on the lighting to have white walls.

    If you can control your environment, then you can work around a lesser camera.
    Bumbling forward into the unknown.

  6. #21
    Join Date
    Dec 2015
    Location
    Dublin, CA
    Posts
    4,119
    Quote Originally Posted by Brian Holcombe View Post
    For instance, I have one area of my shop that I use as a sort of photography spot. I painted the walls around it super white (BM color), added lighting including spot lighting, and I can get some pretty high quality shots out of the phone.

    I noticed I get the most realistic looking color range out of the wood when I'm placing it against a white background, so thats what I did. It also makes it easier on the lighting to have white walls.
    White walls help you in three ways:

    First, they help you avoid mixed color temperatures within an image. As an example of what you don't want, if you have a blue wall then you'll end up with fairly warm lighting on surfaces that are illuminated directly from your light source, and cold lighting in the shadows where most of the light is bounced in. There are cases where you may want that effect, but product photography usually isn't one of them. The same thing happens when you mix flash with ambient, unless you filter the flash to match (some recent phones can do that automatically).

    Second, white walls make life easier for the automatic white balance (AWB) algorithm in the camera by providing a large neutral highlight reference. Most cameras only shoot JPEG, so you're more or less dependent on the camera to get AWB right the first time. If you're shooting RAW with a "real camera" (tm) then this isn't such a big deal since you can clean it up easily in post.

    Third, white walls help keep the scene range within the dynamic range limits of those itsy bitsy sensors by bouncing light into the shadows. Again not as big of a deal with a "real camera".

    On a quasi-related note, have you ever tried cross-polarization? It can really bring out the color in higher-gloss finishes, though at the expense of potentially deadening their appearance. You can even do it with a phone cam...

    Way OT now, except that we are talking about photographing furniture :-).

  7. #22
    Join Date
    Apr 2009
    Location
    Mandalay Shores, CA
    Posts
    2,690
    Blog Entries
    26
    Beautiful dressing job Brian!
    Shawn

    "no trees were harmed in the creation of this message, however some electrons were temporarily inconvenienced."

    "I resent having to use my brain to do your thinking"

  8. #23
    Join Date
    Aug 2013
    Location
    Princeton, NJ
    Posts
    7,254
    Blog Entries
    7
    Quote Originally Posted by Patrick Chase View Post
    White walls help you in three ways:

    First, they help you avoid mixed color temperatures within an image. As an example of what you don't want, if you have a blue wall then you'll end up with fairly warm lighting on surfaces that are illuminated directly from your light source, and cold lighting in the shadows where most of the light is bounced in. There are cases where you may want that effect, but product photography usually isn't one of them. The same thing happens when you mix flash with ambient, unless you filter the flash to match (some recent phones can do that automatically).

    Second, white walls make life easier for the automatic white balance (AWB) algorithm in the camera by providing a large neutral highlight reference. Most cameras only shoot JPEG, so you're more or less dependent on the camera to get AWB right the first time. If you're shooting RAW with a "real camera" (tm) then this isn't such a big deal since you can clean it up easily in post.

    Third, white walls help keep the scene range within the dynamic range limits of those itsy bitsy sensors by bouncing light into the shadows. Again not as big of a deal with a "real camera".

    On a quasi-related note, have you ever tried cross-polarization? It can really bring out the color in higher-gloss finishes, though at the expense of potentially deadening their appearance. You can even do it with a phone cam...

    Way OT now, except that we are talking about photographing furniture :-).
    Hah, indeed pretty far off topic. I've never tried cross polarization, this can be done with an iPhone?


    Thanks Shawn! Fair to say I should not have abused looking tools in my shop.
    Bumbling forward into the unknown.

  9. #24
    Join Date
    Sep 2009
    Location
    Putney, Vermont
    Posts
    1,042
    I had to read up on Ura Dashi because I never heard of it before, and did not understand what Brian was trying to accomplish.

    It reminds me of bringing bowed pieces of tool steel, after being heat treated to straightness again by peening with a ball peen hammer. An older German Tool an Diemaker taught me this many rears ago.

    I made a carbide punch with the end ground to about a 25 degree angle and rounded on the end slightly, to use, instead of the round side of the hammer.

    It moved the metal more precisely for me and helped to hammer with better accuracy and control of amount of impact.

    Very interesting post Brian. Thanks for posting it.

  10. #25
    Join Date
    Aug 2013
    Location
    Princeton, NJ
    Posts
    7,254
    Blog Entries
    7
    Thanks, I think there are some significant similarities there. I've also straightened knives and find the process far far more unnerving than ura-dashi, but also another situation where hard steel can be worked.

    Glad that you have found it to be an interesting topic!
    Bumbling forward into the unknown.

  11. #26
    Join Date
    Dec 2015
    Location
    Dublin, CA
    Posts
    4,119
    Quote Originally Posted by Brian Holcombe View Post
    Hah, indeed pretty far off topic. I've never tried cross polarization, this can be done with an iPhone?.
    You can buy various solutions for mounting filters on an iphone, or you can just tape on the same film as you would for polarizing the light source (Rosco Cinegel is sort of the gold standard for this sort of thing, there are cheaper options as well). For the most part phone cameras don't need circular polarization to function as they don't have polarization-based beam splitters like an SLR.

    EDIT: The idea behind cross-polarization is that you polarize the light source[s] in one direction, and then use another polarizer set at ~90 deg to that direction on your lens. This eliminates specular reflections just like using a polarizer outdoors (in that case the atmosphere polarizes the sun). It's a very old trick in macro and document-copy photography.
    Last edited by Patrick Chase; 01-22-2017 at 3:51 PM.

  12. #27
    Join Date
    Aug 2013
    Location
    Princeton, NJ
    Posts
    7,254
    Blog Entries
    7
    Thanks for the idea! I may give that a try.
    Bumbling forward into the unknown.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •