<html><head><meta http-equiv="content-type" content="text/html; charset=us-ascii"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">David,<div><br></div><div>The conversion rate for counting mode is mentioned in a datasheet of the camera, as a PDF file on some DVD that came with the camera/system.</div><div><div><br></div><div>Best,</div><div><br></div><div>Wim</div></div><div><br><blockquote type="cite"><div>On 6. Jan 2023, at 19:06, Morgan, David Gene <dagmorga@indiana.edu> wrote:</div><br class="Apple-interchange-newline"><div><meta charset="UTF-8"><div class="elementToProof" style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; background-color: rgb(255, 255, 255);">Hi,</span></div><div class="elementToProof" style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; background-color: rgb(255, 255, 255);"><br></span></div><div class="elementToProof" style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; background-color: rgb(255, 255, 255);">I have a stupid question about the MRC files output by our Falcon 3 camera. I just acquired a set of movies in counting mode where the total dose should be on the order of 25 electrons/ A^2, spread over 22 frames. My pixel size is just under 1 A, so my images should have on the order of 20 - 25 electrons per pixel. At least the average over all the pixels after summing or motion correction should be close to that...</span></div><div class="elementToProof" style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; background-color: rgb(255, 255, 255);"><br></span></div><div class="elementToProof" style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; background-color: rgb(255, 255, 255);">When I examine the MRC files output by EPU, I find the following min/max/mean for an example acquisition:</span></div><div class="elementToProof" style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><ol><li style="font-size: 12pt; font-family: Calibri, Helvetica, sans-serif;"><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; background-color: rgb(255, 255, 255);">file with fractions (22 frames): min = 0, max = -1, mean = -2 (obviously bogus values)</span></li><li style="font-size: 12pt; font-family: Calibri, Helvetica, sans-serif;"><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; background-color: rgb(255, 255, 255);">fractions after recalculating min/mix/mean: min = -23, max = 549, mean = 108.27</span></li><li style="font-size: 12pt; font-family: Calibri, Helvetica, sans-serif;"><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; background-color: rgb(255, 255, 255);">summed image (non-motion corrected single frame output by EPU): min = 1239, max = 3809, mean = 2382<br></span></li></ol></div><div class="elementToProof" style="font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; background-color: rgb(255, 255, 255);">My stupid question: How do these numbers relate to what should be the counted number of electrons that hit the specimen? <span class="Apple-converted-space"> </span><br></div><div class="elementToProof" style="font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; background-color: rgb(255, 255, 255);"><br></div><div class="elementToProof" style="font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; background-color: rgb(255, 255, 255);">I suspect that I am seeing some stupid effect of an "average counts per electron" in these images, but I had previously (and I suppose foolishly) assumed that in counted mode images, one count would mean one electron...<br></div><div class="elementToProof" style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;"><br></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;">Thanks for any input you can offer, and Happy New Year.<br></div><div style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt;"><br></div><div id="Signature"><div><div name="divtagdefaultwrapper" style="font-family: Calibri, Arial, Helvetica, sans-serif; margin: 0px;"><div name="divtagdefaultwrapper" style="font-family: Calibri, Arial, Helvetica, sans-serif; margin: 0px;">-- </div><div name="divtagdefaultwrapper" style="font-family: Calibri, Arial, Helvetica, sans-serif; margin: 0px;"> politics is more difficult than physics.</div><div name="divtagdefaultwrapper" style="font-family: Calibri, Arial, Helvetica, sans-serif; margin: 0px;"> A. Einstein</div><div name="divtagdefaultwrapper" style="font-family: Calibri, Arial, Helvetica, sans-serif; margin: 0px;"><br><div name="divtagdefaultwrapper" style="font-family: Calibri, Arial, Helvetica, sans-serif; margin: 0px;"> David Gene Morgan<br> Electron Microscopy Center<br> 047E Simon Hall<br> IU Bloomington<br> 812 856 1457 (office)<br> 812 856 3221 (3200)<br> <span class="Apple-converted-space"> </span><a href="https://urldefense.com/v3/__http://iubemcenter.indiana.edu__;!!Mih3wA!E-FcoZUZdcr3llQ_tQ7nra_aC45SHHOofl5vsdk4RilKOYWBacUzdW1K8BzGLp3U7LbXIfTjwt3E1eA8hKRTl-Y$">http://iubemcenter.indiana.edu</a></div></div></div></div></div></div><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;">_______________________________________________</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;">3dem mailing list</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><a href="mailto:3dem@ncmir.ucsd.edu" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;">3dem@ncmir.ucsd.edu</a><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><a href="https://mail.ncmir.ucsd.edu/mailman/listinfo/3dem" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;">https://mail.ncmir.ucsd.edu/mailman/listinfo/3dem</a></div></blockquote></div><br></body></html>