Follow Me On:
The Adventurous Silversmith
  • Home
  • Blog
  • Portfolio
    • Metal Work >
      • Chasing & Repousse
      • Holloware
      • Jewelry
      • Other Wonderful Items
    • Fiber Arts >
      • Temari
      • Yubinuki
  • Resources
    • Library
    • Tools & Equipment
    • Links
  • About
    • Artist Statement
    • Curriculum Vitae
    • How it is Made
    • Contact

Focus on Depth of Field

5/19/2016

0 Comments

 
Aperture is how open or closed your lens is. This affects not only how much light is allowed in but the depth of field of the subject.
Thus if you want all the subject matter you are shooting, to be in focus, you need a large depth of field and as a result you use a large f-stop this means that the opening in the lens is small.

Yes, it is counter intuitive but just go with it or read this article on the Wikipedia which gets into the math of focal length and size of the pupil of the lens - aperture. 

NOTE: ISO in the film days of photography,  was an indicator of the film's sensitivity to light. Now, ISO, it is used to set the sensitivity of the DSLR sensor. 

Today's self-imposed lesson was to leave the subject and camera position alone. The ISO was also fixed, auto-focus was turned on, the white balance was again custom based upon my lights and to then play with the f-stops to see how the depth of field changed.  These images were taken with the 60mm f/3.2 macro lens. 

I started again with an auto image. This time I used the setting of A-Dep  which sets the camera to get the best depth of field while picking the ISO and the Sutter Speed. The meta data show the following - ISO: 400;  Tv: 1/6; Av: 32.  As you can see the cuff from the front to to the back are all in focus.  
Picture
Next I want to achieve the same with the camera on full manual mode and after that, adjust the f-stops to narrow the depth of field while keeping the ISO constant. 
​Here is my first attempt - ISO: 400;  Tv: 1/30; Av: 32. Which of course because the shutter speed was faster, resulted in a darker image since not enough light was allowed in.
Picture
I slowed the shutter speed down to 1/4 and I got a very close match to the A-Dep picture at the top. 
Picture
In the next series of pictures, I left the ISO at 400, and I halved the f-stop each time (open up the lens) which also means I have to INCREASE the shutter speed, to compensate for the amount of light which would be too much as wash out the image.  Note: In the old days with film cameras you would double the shutter speed to compensate for the halving of the aperture but with DSLR's you can actually go in-between to third stops and get better results.  
To prove this point, this first picture is  ISO: 400;  Tv: 1/30; Av: 18 and as you can see it is over exposed.
Picture
The shutter speed was 1/4 and because halved the f-stop, I should double the shutter speed to 1/8 which I did for this next picture. The image is now, not over exposed but if you look at the back edge of the cuff, you can see that is not quite as in focus which of course is due to the change in depth of field. Also note how the vine just above the blossom is still in focus. 
Picture
This next image is with the f-stop changed to 9 and the shutter speed at 1/80. The color looks as good as the image just above but this time you can really see that both the front edge and the back of the cuff as well as the sides are not fuzzy and out of focus. YES! the change in the depth of field is very visible and the vine is just out of focus. Again the meta-data is now ISO: 400;  Tv: 1/80; Av: 9
Picture
Halving the f-stop again, the meta-data is ISO: 400;  Tv: 1/320; Av: 4.5. Then change in depth of field is even more pronounced as even the vine is very out of focus and the sides and top and bottom are very fuzzy; all because of depth of field is getting shorter. 
Picture
This last image is the extreme end - a f-stop of 2.8 - ISO: 400;  Tv: 1/800; Av: 2.8. You can see that even the back edge of the blossom is now out of focus. 
Picture
Lastly, I decided to change the ISO. The larger the ISO, the more sensitive to light your camera is; and this can result in graininess. The theory is that in LOW-light situations you increase the ISO so you don't have to use a flash but to compensate, in good light, you have to increase the shutter speed.  That is what I did with this picture and here is the meta-data ISO: 800;  Tv: 1/1600; Av: 2.8. If you look closely at this picture below and the one just above it and look at the gold that is textured on the blossom, you should be able to see that the detail, on the lower image, is not as crisp. 
Picture
Today, as you can also see, I have learned how to adjust the camera settings to achieve good images with the right depth of field which requires setting the white balance, ISO, shutter speed (Tv) and aperture (Av).  
0 Comments

Your comment will be posted after it is approved.


Leave a Reply.

    RSS Feed

    How to Aquire Your Own Shop Elf

    Archives

    October 2020
    August 2020
    March 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    May 2018
    April 2018
    February 2018
    January 2018
    November 2017
    October 2017
    September 2017
    July 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    January 2015
    December 2014
    November 2014
    October 2014
    September 2014
    August 2014
    July 2014
    June 2014
    May 2014
    April 2014
    March 2014
    February 2014
    January 2014
    December 2013
    November 2013
    October 2013
    September 2013
    August 2013
    July 2013
    June 2013
    May 2013
    April 2013
    March 2013
    February 2013
    January 2013
    December 2012
    November 2012
    October 2012
    September 2012
    August 2012
    July 2012
    June 2012
    May 2012
    April 2012
    March 2012
    February 2012
    January 2012
    November 2011
    August 2011
    July 2011
    June 2011
    May 2011
    April 2011
    March 2011
    February 2011
    January 2011
    December 2010
    November 2010

    Jan - Nov 2010 History
    File Size: 2272 kb
    File Type: pdf
    Download File

    Jan - Dec 2009 History
    File Size: 2332 kb
    File Type: pdf
    Download File

    Categories

    All
    42
    A Year Of Repousse
    Blacksmithing
    Blogoversary
    Box Project
    Business
    Chasing & Repousse
    Commission
    Education
    Embroidery
    Enamel
    Entries
    Entry
    Exhibition
    Facebook
    Filing
    Fold Forming
    Gold
    Holloware
    Hot Forging
    Hydraulic Press
    Jewelry
    Keum-boo
    Learning
    Leather
    Market
    Metal
    Patina
    Photography
    Polishing
    Publications
    Raising
    Sanding
    Santa Fe Symposium
    Shop Elf
    Sinking
    Social Media
    Soldering
    Store
    Studio Visits
    Superbowl Challenge
    Teaching
    Teapot Project
    Technique
    Temari
    Tin
    Tools
    Vessels
    Visiting Workshops
    Weaving
    Website
    Workshop
    Yubinuki

Powered by Create your own unique website with customizable templates.