<div dir="ltr">A quick note on having students make their own stereo pairs with a cell-phone camera. They often find moving the camera just enough (and not too much) a challenge at first. <div><br></div><div> The instruction to put weight on one foot - take one photo - shift weight to the other foot - take the second photo is easy to follow and leads to just the right IOD offset for most students.</div><div><br></div><div> - Jeff</div><div><br clear="all"><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature">Jeff B. Pelz, Wiedman Professor<br>Carlson Center for Imaging Science, 76-3112<br>Rochester Institute of Technology<br>54 Lomb Memorial Drive<br>Rochester, New York 14623<br><a href="mailto:pelz@cis.rit.edu" target="_blank">pelz@cis.rit.edu</a> 585-475-2783<br><br>This email is confidential and intended for the named recipient(s). In the event the email is received by other than the intended recipient(s), please notify the sender at <a href="mailto:pelz@cis.rit.edu" target="_blank">pelz@cis.rit.edu</a>.</div></div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sat, Mar 21, 2020 at 12:24 PM David Peterzell via cvnet <<a href="mailto:cvnet@lawton.ewind.com">cvnet@lawton.ewind.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style="overflow-wrap: break-word;">In addition to showing them Christopher Tyler’s Stereogram (using Magic Eye examples), I do my best to teach them to free fuse. If that goes well with a few of them, then I teach them how to make their own stereo photos using the cameras on their smart phones. 1. Have your subject hold still. 2. Take a photo. 3. Take a second photo with the camera moved just a couple inches to the left or right, still centered on the subject. 4. Put the photos in something like PowerPoint. 5. Crop and realign the photos as needed (crossed or uncrossed). 6. View This isn’t for everyone, and some people get headaches. But I’ve had many students have a blast with this once they learn this. It has always seemed to me to be a good way to teach about stereoscopic vision and the construction of binocular depth perception. <div><br></div><div>Here are just a few of my own examples, all made on the spot with an iPhone. These sets are made for crossed not uncrossed viewing. If they appear small, click on them to open them. Who can find the Serbian vision scientists? </div><div><br></div><div>Dave</div><div><br></div><div><br></div><div><div style="overflow-wrap: break-word;"><b>David Henry Peterzell, Ph.D., Ph.D.<br>--Professor, John F. Kennedy University, Clinical Psychology Doctoral Program, College of Psychology<br>--Visiting Scholar, University of California, Vision Science Program, School of Optometry</b></div><div style="overflow-wrap: break-word;"><b><br></b></div><div style="overflow-wrap: break-word;"><b>JFKU Top Minds video: </b></div><div style="overflow-wrap: break-word;"><b><a href="http://blog.jfku.edu/john-f-kennedy-top-minds-professor-david-peterzell-phd/" target="_blank">http://blog.jfku.edu/john-f-kennedy-top-minds-professor-david-peterzell-phd/</a></b></div></div><div><br></div><div><img id="gmail-m_-604035104378183339B203FAD2-BE7A-4284-A31B-6076541B8CC0" width="320" height="200" src="cid:170fdfb51fda7b0b8cb1"></div><div><br></div><div><img id="gmail-m_-6040351043781833391D62C773-E8FC-4184-BE14-B6D1A0AD13FE" width="320" height="200" src="cid:170fdfb51fd70a82b932"></div><div><br></div><div><img id="gmail-m_-6040351043781833390033B91B-59C7-4C01-8C6B-8BEB7D1782A0" width="320" height="200" src="cid:170fdfb51fd827a8bee3"></div><div><br></div><div><img id="gmail-m_-604035104378183339BF564735-FC49-495B-AF29-C7B7652D35B1" width="320" height="200" src="cid:170fdfb51fda8053cab4"></div><div><br></div><div><img id="gmail-m_-6040351043781833394C03388A-9830-490E-A2AF-63FC39489CB6" width="320" height="200" src="cid:170fdfb51fdab8b1ceb5"></div><div><br></div><div><img id="gmail-m_-604035104378183339D3DA76B3-AA10-46AF-B332-FE1518670805" width="320" height="200" src="cid:170fdfb51fe7b3f5f286"></div><div><br></div><div><img id="gmail-m_-6040351043781833391DB72ED5-F954-4747-A4D7-0CB7075F1786" width="320" height="200" src="cid:170fdfb51feaf9563897"></div><div><br></div><div><img id="gmail-m_-6040351043781833396AF8A8EB-7830-4AAD-9334-8FF3B780843D" width="320" height="200" src="cid:170fdfb51fe68f35a2d8"></div><div><br></div><div><img id="gmail-m_-60403510437818333901736359-369B-4C71-A50C-719279904253" width="320" height="200" src="cid:170fdfb51fe39266ff39"></div><div><br></div><div><img id="gmail-m_-604035104378183339F675C096-D1D5-4E23-AC9A-D6AD07582856" width="320" height="200" src="cid:170fdfb51fe80712649a"></div><div><br></div><div><img id="gmail-m_-60403510437818333926B66466-823C-49B5-8428-E0E59C22D1D5" width="320" height="200" src="cid:170fdfb51fe5714fa04b"></div><div><br></div><div><img id="gmail-m_-60403510437818333900008AD1-1789-4091-AD0B-A332C9E8F507" width="320" height="200" src="cid:170fdfb51fe235f8b03c"></div><div><br></div><div><img id="gmail-m_-604035104378183339B470381F-DF73-4B84-8ACA-B54870A9BF26" width="320" height="200" src="cid:170fdfb51fe253eaa25d"></div><div><br></div><div><img id="gmail-m_-604035104378183339B5EF2BDC-AE45-4D53-8206-894F528D4A96" width="320" height="200" src="cid:170fdfb51fe88014d27e"></div><div><br></div><div><img id="gmail-m_-604035104378183339406D6E9A-7EC1-461B-8ED7-EF2D07EB757C" width="320" height="200" src="cid:170fdfb51fef00cc089f"></div><div><br></div><div><img id="gmail-m_-604035104378183339A0276B29-A8AA-4F5A-9DA5-6DAC25654E07" width="320" height="200" src="cid:170fdfb51fedef12dcf10"><img id="gmail-m_-6040351043781833393AA54D5F-8E70-4900-8FA1-C5DC831C223B" width="320" height="200" src="cid:170fdfb51fef86ab52111"></div><div><br></div><div>Click on this one to view. (crossed and uncrossed)</div><div><img id="gmail-m_-604035104378183339A96389A3-CF72-4FFC-9C9E-3E2F28A3AAF8" width="320" height="200" src="cid:170fdfb51feb9bb772a12"><img id="gmail-m_-6040351043781833390716099F-8E51-457C-B32C-E3389D970253" width="320" height="200" src="cid:170fdfb51fee5d2a7cc13"></div><div><br></div><div><img id="gmail-m_-60403510437818333946E003BA-E085-4C8C-844B-C28493F3E4B0" width="320" height="200" src="cid:170fdfb51fec08ed08014"></div><div><br><div><div><br>
</div><br><div><blockquote type="cite"><div>On Mar 20, 2020, at 9:50 PM, Christopher Tyler via cvnet <<a href="mailto:cvnet@lawton.ewind.com" target="_blank">cvnet@lawton.ewind.com</a>> wrote:</div><br><div><div dir="ltr">You could try autostereograms, such as the examples on my <a href="http://www.scholarpedia.org/article/Autostereogram" target="_blank">Scholarpedia page</a>. Not everyone can get them, but they're pretty effective for those who can.<div><br></div><div>All the best,</div><div>Christopher</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Mar 20, 2020 at 9:35 PM Lester Loschky <<a href="mailto:loschky@ksu.edu" target="_blank">loschky@ksu.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr">Hi Everybody,<div><br></div><div>If you teach Sensation and Perception, and are currently preparing to teach it remotely, you may have the same question I have: how can you demonstrate stereovision remotely?</div><div><br></div><div>As preface, the following are methods I have used in in-person classes to demonstrate stereo vision:</div><div><ol><li>an actual stereoscope and example stereoimages to share with students (including the classic Julesz square tile random-dot-stereogram image)<br></li><li>example stereoscopic lenticular lens images to share with students</li><li>red/green anaglyph images with sets of cardboard & plastic red/green anaglyph glasses<br></li><li>Google Cardboard plus cell phone to share with students</li><li>random dot autosterographic images</li><li>touching two pen tips together using two eyes versus one eye</li><li>learning about crossed vs. uncrossed disparity using two fingers at different distances</li></ol><div>Unfortunately, my students don't uniformly have access to the apparatuses required for 1-4 above. </div><div><br></div><div>Re. # 3 (red/green anaglyph images), I've thought of having students order a single pair of red/green anaglyph glasses online. However, it appears that the cardboard and plastic ones can only be purchased in bulk. (I guess they're too cheap to sell individually.) They also might not arrive in time, but students could still enjoy them once they get them.</div></div><div><br></div><div>Re. #4 (Google Cardboard), I recall getting a free Google Cardboard from the NYTimes several years ago. However, they are now no cheaper than $5 (Irisu, of India), and likely wouldn't arrive in time.</div><div><br></div><div>Regarding option #5 (random-dot autostereograms), I have found that since seeing random dot autostereographic images in depth requires perceptual learning, a large proportion of students don't manage to learn (within the short time period given in a single class period). (Of course, many students may have a lot of time on their hands now, so they might keep at it long enough to learn to perceive them. But there will definitely be a good proportion of students who don't try long enough to learn, and so don't get it.)</div><div><br></div><div>#6 (touching two pen tips together) is definitely something that can be done remotely. However, it doesn't have the "Wow!" factor of other demonstrations. It is more of an "oh, really..." experience to realize how much worse you are with one eye than two. </div><div><br></div><div>#7 (using two fingers at different distances to teach crossed vs. uncrossed disparity) can definitely be done remotely. It is very educational, but again does not have the "Wow" factor. </div><div><br></div><div>There is also the finger "hot dog" illusion, which can be done remotely. It is interesting, but quite different from all of the others in that stereoscopic depth perception is not involved.</div><div><br></div><div>For the related phenomenon of motion parallax, "wiggle vision" is a very nice demonstration:</div><div><div><a href="http://www.well.com/user/jimg/stereo/stereo_gate.html" target="_blank">http://www.well.com/user/jimg/stereo/stereo_gate.html</a></div></div><div><a href="https://www.3dwiggle.com/2016/06/28/5-wigglegrams-you-need-to-see-before-you-die/" target="_blank">https://www.3dwiggle.com/2016/06/28/5-wigglegrams-you-need-to-see-before-you-die/</a><br></div><div><br></div><div>Of course, depth perception from motion parallax is importantly theoretically related to stereoscopic vision (both involve two different images from two different views, one seen over time (and only needing one eye)--motion parallax--and the other seen simultaneously (and requiring two eyes)--stereovision). But it is not the same as stereoscopic vision, so is a separate but related issue.</div><div><br></div><div>For the related phenomenon of binocular disparity, there is the famous "hole in your hand" illusion using a cardboard paper towel roll. If students have a spare cardboard paper towel roll, they can do this remotely. But, again, it is a theoretically related but separate issue. </div><div><br></div><div>Any other suggestions would be appreciated. </div><div><br clear="all"><div>Best wishes,</div><div><br></div><div>Les</div>-- <br><div dir="ltr"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div>Lester Loschky</div><div><div>Professor</div><div>Associate Director, Cognitive and Neurobiological Approaches to Plasticity Center<br>Department of Psychological Sciences<br>471 Bluemont Hall</div><div><div>1114 Mid-Campus Dr North</div>Kansas State University<br>Manhattan, KS <span style="font-size:10pt;font-family:Helvetica">66506-5302</span> </div></div><div>email: <a href="mailto:loschky@ksu.edu" target="_blank">loschky@ksu.edu</a></div><div>research page: <a href="https://www.k-state.edu/psych/research/loschkylester.html" target="_blank">https://www.k-state.edu/psych/research/loschkylester.html</a></div><div>lab page: <a href="http://www.k-state.edu/psych/vcl/index.html" target="_blank">http://www.k-state.edu/psych/vcl/index.html</a></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div>
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