Print Page   |   Sign In   |   Join OPS
Search




 

 

  

  

  

OPS Blog
Blog Home All Blogs
Welcome to the Ophthalmic Photographers' Society Blog! The posts on this blog are authored by a myriad of individuals in Ophthalmology. Posts are not always authored by those directly affiliated with the Ophthalmic Photographers' Society and opinions may not be those of the OPS; however, all posts are submitted to a review process and have been approved by the OPS before being posted. Comments are open to the public. New posts are added every Friday, so make sure to check back often!

 

Search all posts for:   

 

Top tags: blog  PDC  education  Educational Meeting  Travel  Ice Breakers  Meaningful Use  Interactive  cute  Mid-year  Professional Development Committee  funny  Special Events  New Life  Study  AAO  Tips  school  Chicago  2015  Ann Arbor  Professionalism  Social Media  2016  ICOP  Kellogg Eye Center  Facebook  Fort Worth  JJJ Award  Keynote Speaker 

Wow, what a difference!

Posted By Houston P. Sharpe III, Friday, August 28, 2015
Updated: Friday, August 28, 2015

I have always enjoyed attending OPS meetings and webinars.  During my first OPS meeting I knew almost no one. Each year since, I have met many new people who are interested in or already immersed in ophthalmic photography.  I am always excited to return home and apply these new tips and tricks during our clinic and observe the resulting differences.   Seeing the change in quality, that resulted from implementing the knowledge gained from the OPS continuing education programs, has impressed upon me the fact that we have a responsibility to continue our education in order to improve our skills.

Recently, I had a difficult view during a FA on a traditional fundus camera due to a severe cataract in the transit eye.  After finishing the mid-phase photographs I felt less than thrilled with my performance.  I thought about a trick that I remember hearing during a lecture at an OPS meeting, "If you have a difficult view through a cataract for a FA, use the Heidelberg”.  Wow, what a difference!  That severe cataract was causing very little distortion to the averaged image I was able to quickly obtain.  After showing my fellow photographers and the attending, I told them the trouble that I had and how I circumvented it.  I felt even more joy from passing on the technique to those around me, hoping that one day it will make a difference in someone else’s treatment. 

I hope to see y’all in Las Vegas for this year’s annual meeting where we can all learn from each other!

 Houston P. Sharpe, III, COA, OCT-C (top); Debra Cantrell, COA (bottom).

Tags:  2015  AAO  blog  cute  education  Educational Meeting  Fluorescein Sodium Dye  Ice Breakers  Meaningful Use  research  Special Events  Tips  Travel  Tricks 

Share |
PermalinkComments (4)
 

Stereo Scanning!

Posted By Timothy J. Bennett CRA, OCT-C, Friday, May 10, 2013
Updated: Friday, May 10, 2013


A flatbed scanner is often used as a small object camera for flat subjects. Surprisingly, they are also capable of imaging small three-dimensional objects as well. The optics in a flatbed scanner are designed to record the entire 8.5 x 11 (or larger) scanning bed on a small sensor. In order to do that, the scanner utilizes a wide angle lens with mirrors or prisms to place the sensor at an optical distance much greater than the actual physical distance of the shallow scanning bed.

Although the plane of focus is set at the surface of the glass plate, the optics provide better than expected depth-of-field, enabling a reasonable degree of sharpness in small three-dimensional subjects imaged on the glass bed.

The optics also introduce a certain amount of parallax when a three-dimensional object is moved to different lateral positions on the scanning bed.

You can see the effect here with this film box placed in left, center, and right positions on the bed. This parallax allows for generation of sequential stereo pairs much like the stereo pairs we create by shifting the fundus camera laterally between two sequential photos.

With standard stereo photography, the typical camera shift distance between photos is 2.5 inches which approximates the average distance between eyes. Another commonly used convention is to shift the camera 1/30th of the distance to the nearest point in the scene. The optical properties of a scanner render these common conventions irrelevant. I suggest experimenting with your particular scanner to judge a good distance between images but I've found that one to two inches works well, and sometimes as little as half an inch produces enough parallax to achieve a stereo effect.

Alignment between successive scans of unevenly shaped objects can be challenging. Objects can roll or shift between shots, distorting the stereo effect. If necessary, objects can be attached to a firm background with tape or glue. A glass front box can also be used to hold the object on the scanner. In both of these cases, the glass box or background is easily moved side-to-side on the scanning bed between shots to create parallax while maintaining the same object orientation.

The optics of the scanner are usually sharpest near the center of the scanner bed, so try to place objects near the middle. Judicious use of a Sharpen or Unsharp Mask filter in your photo editing software may help as well. When aligning the stereo pairs for viewing, any vertical displacement must be avoided. Leave some empty space around the object to allow for cropping any excess vertical overlap.

To achieve a dark background, you can simply leave the scanning lid open and turn off any ambient room light. Placing the scanner lid over the object will result in a lighter background that varies with the distance of the lid from the bed.

To prevent the lid from pressing against fragile objects or accidentally moving the object during lid placement between successive images, small blocks of foam board can be used to prop the lid above the object.

Several years ago, I read of a technique for scanning three-dimensional objects by placing them in a shallow box and inverting the scanner on top of the box. The objects shown above were placed in a shallow box lid and imaged with this technique, but I don't recommend it. Placing the scanner upside down can wreak havoc with the gears in the scanning carriage or stepping motor.

Once you've captured stereo pairs, they can be cropped, aligned, and rendered as anaglyph images in photo editing software or in dedicated stereo alignment software such as Stereo Photo Maker.

Give this technique a try and have fun!

The following anaglyph images were all done on a flatbed scanner. To view these images in stereo, use red/cyan (blue-green) anaglyph glasses with the red lens covering the left eye.

To see an anaglyph video clip panning across this image, click here

 

 

Timothy J. Bennett, CRA, FOPS, OCT-C, is an ophthalmic photographer in the Penn State University Department of Ophthalmology at the Milton S. Hershey Medical Center. Mr. Bennett has over 30 years experience working in university-based academic medical centers. He is a nationally recognized author, lecturer and educator in the field of ophthalmic photography. Areas of expertise include fluorescein angiography, digital imaging, monochromatic photography, fundus autofluorescence and optical coherence tomography. Mr. Bennett holds current certification as a Certified Retinal Angiographer and Optical Coherence Tomographer, is a former Commissioner of the Joint Commission on Allied Health Personnel in Ophthalmology, and has been recognized for his contributions to the profession by being named a Fellow of the Ophthalmic Photographers Society. He has served on the OPS Board of Certification, the OPS Board of Directors, and is Past-President of the Ophthalmic Photographers' Society.

Tags:  blog  education  Educational Meeting  Ice Breakers  Interactive  Meaningful Use  PDC  Photoshop  Scanning  school  Stereo  Study  Tips  Tricks 

Share |
PermalinkComments (3)
 

Tips-N-Tricks

Posted By Rachel A. Hollar CRA OCT-C, Friday, July 27, 2012
Updated: Friday, July 27, 2012

Photographers, of all stripes, have a little (or not so little) box-o-tricks that they draw from often in order to shape/manipulate/control the reflected light rays they are capturing. Reflector cards to bounce light into shadowed crevices, tinted reflectors to warm or cool the light and diffusers of all shapes, sizes and tints to spread and soften light. Q-tips, cotton balls, tooth-picks, syringes, spray bottles, fishing wire, mirror shards, tape, plumber’s putty…. Are all commonly found in a studio toolbox.

 


(http://blog.mountainliving.com/wp-content/uploads/2012/04/Grandpas+Toolbox1.jpg)

 

Take food photography for example. Soooo many tricks are utilized to present the viewer with a final, mouth watering image.

That ice-cream you see, mashed potatoes or, more commonly, Crisco, corn syrup and powdered sugar mixed with food coloring. Chocolate syrup; try motor oil. Those yummy cherries, sprayed with hairspray, or Vodka to keep them from looking too shiny. That melted marshmallow topping; Elmer’s glue (also used as ‘milk’ in cereal).

 

 

The scrumptious meats we drool over in advertisements (or retch, depending on what you eat), let me fill you in on some of those secrets…. Steaks or burger; you are looking at a piece of raw meat, chicken and fish as well, with copious amounts of vegetable oil brushed on to make them look hot from the grill or oven. The meat is warmed up just enough to loose any stiffness. The outside of burgers and steaks are brushed with brown shoe polish to give it a cooked appearance. Hot metal tongs or skewers are placed on the meat to achieve those perfect grill lines. A handheld torch is used to crisp up the edges until they glisten and drip with meaty goodness. Mashed potatoes are injected under the skin of chicken, before the torch is used, to give it the fresh, hot, plump and juicy look.

 

 


Cotton balls, soaked in water and then nuked for a minute or two are perfect for adding steam to an image. Incense, cigarettes or modified steamers can also be used. (Now-a-days it is MUCH easier to obtain those perfect plumes of steam using Photoshop rather than relying on the fickle nature of the elements.)

 

(http://farm8.staticflickr.com/7007/6720112873_0a737ca680_z.jpg)


As a disclaimer, food imaged for the purpose of informing the consumer of what they can expect to find in the package they just bought HAS to be that food itself.  If you are buying a box of ice-cream cones, the ad on the box will always utilize the real cone. Anything else you see included with the cone is probably contrived.

In ophthalmology we also make use of many tips and tricks to achieve the desired results in our images. Artificial tears for dry eyes. Q-tips for those long long lashes (or eyebrows). Q-tips for the raising of eye lids themselves as they valiantly strive to block our light from those sensitive eyes.  For the excessive blinkers, having them count to, say 5, in their mind between blinks buys time to take a usable image. For children or those older individuals who are less then co-operative when administering eye drops, placing the drops on the outside of the closed lid and then having the person SQUEEEEEZE their eye tight then open wide quickly can get the job done, drop in.  For those patients who are, um, nasally gifted, having them turn their head slightly to the side can make all the difference when trying to maintain the proper working distance.

 

(http://randomshortjokes.com/wp-content/uploads/2011/05/Politically-Correct-Term-For-Large-Nose.jpg)

 


We have tricks to deal with poorly located floaters (look left then right then back at target, quickly). Nystagmus or other movement issues (and people always told me those video games were a waste of my time – HA!). We have tricks to distract children (tell me what colors you see after the light flashes…). Fixation issue? No problem! Look at my ear, look at the spot on the wall behind me, look at this clock hour, etc…

The list goes on! I am sure each practice utilizes their own unique problem solving solutions – If anyone has a few they would care to share the rest of us will listen attentively :)

 

 

Rachel Hollar, CRA, has been a member of the OPS Professional Development committee since 2011. She transferred into the biomedical photography program from photo advertising at RIT. Rachel started working at the University of Rochester Eye Institute following graduation in 2007.

Tags:  blog  education  funny  Meaningful Use  PDC  school  Study  Tips  Tricks  Work arounds 

Share |
PermalinkComments (1)
 
Sign In


Latest News
Calendar

7/8/2020
Webinar Wednesday

 

 

COPYRIGHT © 2011-2019 THE AUTHOR(S) AND THE OPHTHALMIC PHOTOGRAPHERS' SOCIETY INC.
ALL RIGHTS RESERVED.