[HDR-photo] (no subject)

[Ferrell McCollough]

Perry,
There are two functions that need to be distinguished, Exposure Compensation and Auto Exposure Bracketing (AEB). 

You are trying to work with Exposure Compensation. That is the  +/- button on the back of your camera. Let's say you wanted to dial in a picture to be +2 overexposed. Hold in the +/- button and rotate the front button. As you rotate the button it will advance in 1/2 or 1/3 increments depending on your custom setting. To get to +2 exposure, when you choose 1/2 increment you'll have to move the dial 4 clicks and at 1/3 increment you'll have to move the dial 6 clicks. User choice can be set in the custom settings and that's where you are seeing 1/2 or 1/3.

Auto Bracket Compensation is an entirely different function that is set by pressing the Black Square/White Square image on the back left of the camera. The front dial sets number of frames the rear dial sets increment (possibly reversed). This camera is pretty powerful in its range of AEB. Play around with it and you'll find that you can dial in 5 exposures at 2EV spacing. It's cool.

Hey Royce, thank you for adding my tutorial, it's a nice vote of confidence coming from a consummate professional like you.

Good Luck,
Ferrell
www.beforethecoffee.com


  ----- Original Message ----- 
  From: Perry Frantzman 
  To: High Dynamic Range Photography 
  Sent: Tuesday, October 02, 2007 8:42 PM
  Subject: Re: [HDR-photo] (no subject)


  Hi Royce;
  Still a bit confused about the Pentax 10KD AB and EV spacing
  In the  Custom settings I can
  1)EV Steps can be either 1/2 or 1/3 steps
  I hope that means one half and one third

  2)Auto bracketing order
  choice of 3 frames or 5 frames with different shooting orders.

  The only other thing would be Sensitivity Steps
  which is a choice between
  ISO sensitivity steps are set to 1 EV  or
  ISO sensitivity steps are in accourance with EV Steps

  What do you think gets me the biggest spread and how much would that be?
  Thanks in advance

   
  On 10/2/07, Royce Howland <royce at cospring.com> wrote: 
    Don Kuespert wrote:
    > I want to streamline the HDR process by using  RAW, produce three
    > exposures separated by a speed factor of 4 to 8, all at the same 
    > aperture to control depth of field.

    Don, I'm not sure what you mean by "speed factor". If you mean the
    factor for dividing/multiplying shutter speed, this equates to 2 - 4
    f-stops (or EV). Merging multiple exposures into a single HDR file is a 
    sampling process. The wider the gap between samples the more potential
    there is for reduced quality in the results. I think most folks on this
    list are using exposures 1 - 2 EV apart; personally I don't recommend 
    stepping exposures farther apart than 2 stops.

    Partly this is determined by the exposure bracketing function of your
    camera. Again, I reckon most are using AEB rather than manually
    adjusting exposure for each successive frame. AEB means you touch the 
    camera less, leading to less potential for image registration problems
    during the merge. And AEB also means shooting through the frame sequence
    faster which may reduce the amount of mismatch potential from objects 
    that move within the frame.

    You are correct to maintain the same aperture to hold DOF constant.

    As others have stated, how many shots you need separated by any given EV
    spacing depends in large part on how much dynamic range exists within 
    the scene, and how much of it you need to capture for your purposes. A
    good tutorial on how to bracket your shot sequence can be found here:
    http://beforethecoffee.wordpress.com/bracketing-number-of-images/

    I also discussed the matter, though less thoroughly :), in my older HDR
    tutorial at NatureScapes.Net:
    http://www.naturescapes.net/072006/rh0706_4.htm#exposure

    > Will this produce high quality HDR?

    I'll leave this question for now since the issue of quality is
    subjective and depends on many factors. :) 

    Royce Howland
    Calgary, Alberta

    _______________________________________________
    HDR-photo mailing list
    HDR-photo at hdr-photography.com
    http://www.hdr-photography.com/mailman/listinfo/hdr-photo




  -- 
  Perry Frantzman 


------------------------------------------------------------------------------


  _______________________________________________
  HDR-photo mailing list
  HDR-photo at hdr-photography.com
  http://www.hdr-photography.com/mailman/listinfo/hdr-photo
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.hdr-photography.com/pipermail/hdr-photo/attachments/20071002/9f988024/attachment.html