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Message: <blockquote data-quote="JGobeil" data-source="post: 1237317" data-attributes="member: 24649">Ok, here is the new Version 2.0 protocol with the revised target.  Let's hope it is the last revision...Besides the new target, I have removed the mandatory requirement for those elements that are not required to compare meaningfully.Prime focus digiscoping protocol - V. 2.0(Revised 08.07.06 17:15 EST)PLEASE FOLLOW EXACTLY ALL THE INSTRUCTIONS IN THIS PROTOCOL AND DO NOT CHANGE ANYTHING.  We won’t be able to compare meaningfully if we don’t use the EXACT same settings.1- To begin this experiment, the test will be limited to a DSLR connected directly to an astro refractor scope. Nothing else: no teleconverters or barlows.  Use spacers ONLY if they are required to get the target in focus.  As soon as we are satisfied with the protocol we will open it to other setups.2- The DSLR must be set to its standard settings. Of particular interest is the internal sharpness setting which should be set at the DEFAULT VALUE. It should be set at its maximum megapixel value if any choice is offered.3- The target to be used is derived from a standard ISO 12233 test chart.   It has been modified so that everybody can print it with a standard home printer and resolve the finest resolution.  The file containing the target in JPEG form is available here.  Right click on the image and copy.<a href="http://julesgobeil.com/private/digiscoping%20target%20v2_0.jpg" target="_blank">http://julesgobeil.com/private/digiscoping%20target%20v2_0.jpg</a>Only this file should be use as a source for the target. This target has those dimensions:10.0 x 7.7527 inches (254.0 x 191,18) at 300 pixels/inch (118,11 pixels/cm).  The complete image should be included in the target, do not crop out anything.  This size will fit A4 and Letter size paper with an adequate margin for all printers. After printing, the dimensions should be checked to make sure they are the same as the original file.4- Find an adequate place to photograph the target under sunny conditions with little or no wind. Put the target on a firm background like a cardboard box or a piece of wood and fix it solidly so that it doesn’t wobble and its surface is perfectly flat.   You must put it at a distance where the target will exactly fill the width of the viewfinder – no more, no less.  The sun should be facing the target – behind your back when you take the picture. Make sure that the target is perfectly vertical and that the camera is at the same height as the target. Use a sturdy tripod and head - lock everything so it doesn’t move.   These recommendations about sun, wind and setup stability are not mandatory but are most important to ensure a sharp picture.5-  If possible use mirror lock-up and timer activated shutter or remote cable. Set the camera at ISO 400 (not mandatory) and adjust the shutter speed for proper exposure.  Take the photograph using RAW if it is available – if not, use JPEG at the highest resolution possible.  Focus with extreme care and take a few pictures, keeping the one with the most accurate focus.6- Resize the COMPLETE photograph of the target to 1024 pixels wide and convert to JPG if you shoot RAW.   DO NOT CROP AND DO NOT PROCESS IN ANY WAY. NO SHARPENING PLEASE !  Attach this picture to your post.  If the file is too big to upload, reduce the JPEG quality (In Photoshop, set it to 8).   7-  Studying the target, evaluate the BEST resolution number.  This is the highest number where you can see WHITE SPACE BETWEEN ALL FIVE BLACK LINES. 8- Publish your picture with the following information:Make and model of DSLR:Make and model of scope:Type, make and model of camera adapter:Length of spacer needed to reach focus: Focal length of complete setup in mm:Measured distance between target and telescope in meters:Evaluated resolution number:Speed setting of camera:ISO:Original picture format (RAW, JPG) and resolution (mpx)Date and time:Weather conditions (sun and wind):Other pertinent information:Target resized at 1024 px wide attached.</blockquote>

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