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Dennis last won the day on February 18 2014

Dennis had the most liked content!

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About Dennis

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  1. Hi Erik, Like you I am a beginner. But so far I have not found it necessary to darken the ball bearings for my work doing highlight method micro-RTIs. The software seems to capture the highlights on bright metal just fine. I'd be more concerned about any coating attempt creating surface irregularities or other unevenness on the bearing. Best, Dennis
  2. Wow this looks terrific Tessa. The mobile app makes an RTI product so accessible so immediate and navigable (with one's finger) it may be a game changer. What I mean if it's not obvious is that we all get hooked on it by our first experience of the RTI product - while the creation of RTI products is another matter. Like all photographic processes they are best made through experience. So publishing the product widely through mobile devices will hook many more people and some of those will begin to learn how to make RTIs and that will widen our user and knowledge base. Bravo! Another game changer is that Artis C is charging for the software. I hope we can talk about that here. As you know CHI has been providing us with free access to RTI capture, process and viewing software that was created by themselves in collaboration other researchers around the world. CHI asks for donations rather than charging for their software. I understand that things cost money to develop, that entrepreneurialism is valuable and that one is due some profit. But I also love the dedication and generosity of workers who produce open-source software expecting no additional remuneration beyond their base salaries, donations (or nothin') and whose capture and processing work makes a viewing product like that of Artis CT possible. So in that context and with no disrespect intended how am I to understand the $99 charge for the RTI mobile app? Dennis
  3. FWIW, Here is a second source, from three of the authors' home page, downloadable at no charge: http://vcg.isti.cnr.it/Publications/2010/PCCSM10/jocch2010.pdf
  4. I may be out of step here (marching to a different drummer, dancing to a different beat, swimming in the wrong school?). But I see web-based resources as processes more than products. Unlike printed bibliographies they go off, become moribund, very quickly. To me a good web-based biblio will take advantage of that venue's connectivity and maintain active links to official sources as well as gray lit. resources such as author's copies. If links to full text are not freely allowed the biblio should link to an abstract. This kind of updating is separate from keeping the actual citations current. Wherever the central biblio is located it's best that it be collaboratively maintained to assure that the links are kept current. For example after being away from it for a year I just looked at the RTI_help bibliography (public version) and many website links need to be redirected. They now return '404s', 'Page Not Found' after only one year! It is still usable as an old-school dated bibliography (2011 is the latest citation year), but to me that's not enough for a web-based 'product'. RTI users need all the connectivity they can get. This forum demonstrates that every week! Mendeley is a powerful resource, much more than a biblio tool, and I think the RTI bibliography, (search for the Mendeley Group titled 'RTI'), that Hembo started should be maintained as a central go-to resource. (If you are a member of Mendeley you should also look at this link to the Group titled 'Conservation Science and Imaging'. It's another biblio that references RTI.) But I also think a resource that is less structured, e.g., one that allows links to author's versions, is also helpful. For me a problem more vexing than centralization or authority is how to make sure the resource is actively maintained with all the connectivity possible.
  5. James, I work for a university's archaeology department doing highlight captures of small artifacts. At $5K I may well be able to scrape up the funds for a dome. Typically we'll use it to image whole artifacts. I see the dome's diameter is 22". What maximum size artifact would that restrict me to? In our discussions here I'd want to be able to say something like, "For artifacts x size and smaller we'll use the Relightable Dome and for larger artifacts we'll use highlight capture." Dennis Dennis Piechota Archaeological Conservator Fiske Center for Archaeological Research UMass Boston Office: 617-287-6829 dennis.piechota@umb.edu
  6. Bravo and Congratulations David, I look forward to the link! Best, Dennis
  7. In defense of the American Institute for Conservation, to which I belong, it has a very small staff, just a couple people in an office handling all member activities as well as all book orders. My copy of the popular Guide also arrived a month after I ordered it. Amazon has changed our expectations to a speed that small non-profit staffs can not match.
  8. Marlin, Thanks for the post on Screen Flow. It looks great. For those of us for whom even the low cost ($99) of Screen Flow is a stretch I recommend the free version of a utility called Screen Record Utility Lite Version 2.0, downloadable from the App Store. It gives the Apple Mac user the ability to make movies of their RTIviewer files lasting up to 300 seconds. For $4.99 that maximum time limit is removed but five minutes of viewing a single interactive RTI is a long time! The recordings are saved in .mov format at up to 30fps without a watermark. From my tests of the demo version of Screenflow and the free Screen Record Utility Lite it's clear one gets value, primarily video editing and .mp4 formatting, for the $99. However the free utility does give quick Powerpoint insertable movies of RTIs that run and look fine. Dennis iMac 2011 OSX10.8.4 PPT 2011 v14.3.5
  9. I get an error message when trying to open forums.culturalheritageimaging.org on my iPhone 4S. Am I the only one? The error reads: Fatal error: Call to a member function primary_navigation() on a non-object in /home/chiforum/public_html/admin/applications_addon/ips/ccs/sources/hooks.php on line 93 Apologies if this is the wrong place to post this question. Please feel free to move it to the proper forum. Dennis PS: Opens fine on an iPad!
  10. the ball itself... is far less stable underwater sitting on it's little metal nut I glued to it with a British coin onto it as well) than one might think. Yeah the difference between weight in air and weight in water takes some getting used to when you want things to not only sit on the seafloor but also stay in place. I once wasted a lot of time making sure every component of a (non-RTI) experimental design was negatively buoyant only to see it slide about on the seafloor. I learned to bring a lot of large lead weights!
  11. Graeme, Congratulations on receiving the funding for this project! When it comes to developing products I always have to review the basics. I apologize if this is too much so. Like everyone I turn to processing an RTI when confronted with a surface that is hard to interpret. In that situation an RTI does two things. First it allows me to develop an interpretation of the surface; then the RTI Viewer allows me to convey that interpretation to the 'unconvinced'. I find those curmudgeons are won over by THEIR being able to mouse over the trackball in the RTI Viewer, to do the 'RTI jitters', moving the light source back and forth dynamically and repeatedly to develop in their minds a 3D understanding of the surface. So it's ironic that I must make sure my captures are small enough to enable this capability of the RTI Viewer. Mouse-clicking from one light position to the next, as one does when viewing RTIs of larger files, does not have the same power. It doesn't engage our mind's ability to construct three dimensional images the way dynamic mousing does. We know from previous posts the why and how of this (see RTI Viewer: trackball). So as the speed of our connections and the power of our computers develops I hope there will be a focus on developing our capability to dynamically present large files.
  12. Looks great David! I'm wondering if the 'blur' that appears on the snooker TIFF could actually be the light reflecting off the surface of the water. Was the bulb shielded? Great to see an underwater RTI!!!
  13. David, I'd love to see your results! Perhaps your upload limit can be increased here by admin. If not I suggest you open a free Google Docs/Google Drive account and upload the file there giving it open sharing privileges i.e., anyone with the file address can view/dl, and then post a link to that address here. Last check Google Docs allows free accounts with up to 5 Gigabytes of total storage. Not sure what the maximum size limit for an individual file but I've uploaded files larger than 150 Mb.
  14. As an archaeological conservator much of the discussion has flown way over my head. I see RTI as a technology well-suited for the fast developing field of deepwater archaeology where the cost of conventional excavation is prohibitive. All work is done robotically with tethered or autonomous underwater vehicles. In-situ study, preservation and monitoring will be called for. It is remarkable how difficult it is to interpret fine detail on underwater surfaces when they are viewed on shipboard monitors even using HD video from 3-chip cameras. There is no light in deepwater and one's lighting dissipates rapidly as one moves away from a surface. RTI still captures will overcome some of this by allowing us to use what I think of as the 'RTI-jitters', mousing back-and-forth over the image, to mentally re-construct topography. Besides the aid they will give to shared study of deepwater artifacts or assemblages, RTIs will make great museum display exhibits at nearby coastal state museums. These museum are being considered as ways to monitor sites to discourage looting. Linked by video cables to the deepwater wrecksite 'live' using remotely controlled bird-on-wire cameras the displays will allow constant monitoring. But lets face it after a while of viewing a static video everyone starts to focus on the shrimp on top of the amphoras rather than the artifacts. So RTI displays of artifacts will be great interactive supplements to re-direct the focus. Besides the many practical problems working underwater I'm wondering how we will deal with 'marine snow'. When viewing UW scenes we mentally edit the floating debris between ourselves and the surface. I'm guessing multiple images at each light position combined with processing out anything that moves? Talking about deepwater applications, though a great goal, sounds like talking about doing RTIs on the moon, the recommendation to begin in a clear pool sounds like wise advice.
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