mark u Posted August 18, 2005 Share Posted August 18, 2005 Does anyone KNOW what the image circle is for each of the EF-S lensescurrently available? Likewise, the maximum distance between the lensmount flange and the rear protrusion of the lens (this will vary withzoom/focus distance)? It occurs to me that Canon may have designed these lenses so theyprovide adequate coverage on a 1.3 crop sensor, and that a doublemotion mirror (as originally seen on the first Digital Rebel) mightallow clearance of the rear element. The more complicated mirrormovement would act as a limitation on maximum frame rate achieveable. However, it could allow a 20D successor to remain EF-S compatiblewhile having a 1.3 crop sensor. It would also offer some comfort tothose investing in EF-S glass who feel that they might consider a 1.3crop in the future if it is offered (as seems likely from Canon'sstatements about the future of 1.3 crop - it will disappear from the 1series, but not completely from the EOS line). Link to comment Share on other sites More sharing options...
peter_white2 Posted August 18, 2005 Share Posted August 18, 2005 If that were so, why wouldn't Canon incliude that in their specs for the EF-S lenses. Don't they clearly state that they are for APS-C sensors? Link to comment Share on other sites More sharing options...
mark u Posted August 18, 2005 Author Share Posted August 18, 2005 You may be right so far as the non USM 18-55 kit lens is concerned, but close examination of the EF lens chart shows that as the only EF-S lens with a red asterisk: http://consumer.usa.canon.com/app/pdf/lens/EFLensChart.pdf I think I smell a rat! Link to comment Share on other sites More sharing options...
daniel_nordling1 Posted August 18, 2005 Share Posted August 18, 2005 Short answer, it differs from model of lens and focal lenght.<p> Longer answer, (allthough i can not find my notes with the exact measurements) in my experience the 10-22 EF-S covers full frame down to about 15-16 mm and 1.3 crop to around 13-14 mm.<p> <a href="http://daniel.nordling.nu/foto/EF-S-10D/EF-S-10-22-14mm-ff-xl.jpg"><img src="http://daniel.nordling.nu/foto/EF-S-10D/EF-S-10-22-14mm-ff.jpg"></a><br> Full frame image from EF-S 10-22 at 14 mm, click on image for full size scan (almost 4 Mbyte). Markings represents 1.3 and 1.6 crop.<p> <img src="http://daniel.nordling.nu/foto/EF-S-10D/EF-S-10-22-12mm-ff.jpg"><br> Full frame image (EOS 30 slide) from EF-S 10-22 at 12 mm. <p> The full frame mirror of my old EOS 30 goes clear of the rear lens element down to about 12 mm, my guess from this is that the lens should be perfectly usable a 1.3 crop body down to the limits of image circle coverage. I should think that the mirror is less of a problem on the 17-85 EF-S (or the 18-55 EF-S for that matter), but i have no information on the image circle of those lenses. <p> See also my description on <a href="http://daniel.nordling.nu/foto/EF-S-10D/">Adapting the Canon EF-S 10-22/3.5-4.5 for use on a Canon EOS 10D</a><p> /Daniel<p> Ps. I take no responsibillity for any possible damage caused by this information.<p> Link to comment Share on other sites More sharing options...
jbq Posted August 18, 2005 Share Posted August 18, 2005 With a fixed pellicle mirror the issue of clearing the mirror disappears. With the 1.3x crop seemingly going toward high-speed shooting and high-ISO noise being under control, I wouldn't be surprised to see a future mark of the 1D use a pellicle mirror. Link to comment Share on other sites More sharing options...
jon_austin Posted August 18, 2005 Share Posted August 18, 2005 "However, it could allow a 20D successor to remain EF-S compatible while having a 1.3 crop sensor. It would also offer some comfort to those investing in EF-S glass who feel that they might consider a 1.3 crop in the future if it is offered (as seems likely from Canon's statements about the future of 1.3 crop - it will disappear from the 1 series, but not completely from the EOS line)." I've read that Canon plans to consolidate the 1D and 1Ds to a single product in the future (perhaps even within the next year?), but I've not read anything about the 1.3x crop surviving this consolidation. In fact, the interview of Canon's CEO in January that I read suggests just the opposite: that Canon plans to eliminate the 1.3x crop. Canon never represented the EF-S mount as ever being compatible with anything other than 1.6x bodies beginning with the dRebel. No doubt there will be those who may one day regret their investment in these lenses, probably because the migration to full frame dSLRs happened more quickly than they expected. (These things always seem to have happened more quickly in retrospect, don't they?) But none of those regrets should be based on any illusions of promises broken by the manufacturer. Link to comment Share on other sites More sharing options...
mark u Posted August 18, 2005 Author Share Posted August 18, 2005 Daniel - thanks for your graphic(!) contribution on the 10-22. Link to comment Share on other sites More sharing options...
JeffOwen Posted August 18, 2005 Share Posted August 18, 2005 Daniel, in you excellent examples on converting the 10-22 lens do you think the that the limiting image circle is in fact not helped by the filter that you have to fit to limit the min focal length? Link to comment Share on other sites More sharing options...
daniel_nordling1 Posted August 18, 2005 Share Posted August 18, 2005 You are of course right, the filter is adding quite a bit of the vingeting at these focal lenghts (as the lens is not constructed for full frame usage). Judging from the viewfinder you might be able to use one millimetre shorter focal lenghts without filter, sorry i did not think of this when I made my test shots. /Daniel Link to comment Share on other sites More sharing options...
mark u Posted August 18, 2005 Author Share Posted August 18, 2005 Jon - maybe you missed this interview with executives from Canon Spain: http://www.quesabesde.com/noticias/1_1717 Link to comment Share on other sites More sharing options...
jon_austin Posted August 18, 2005 Share Posted August 18, 2005 ?No hablo Espa�ol, Se�or! Link to comment Share on other sites More sharing options...
jon_austin Posted August 18, 2005 Share Posted August 18, 2005 (OK, no high-order-bit ASCII characters ...) No hablo Espanol, Senor! (Just doesn't look right this way...) Link to comment Share on other sites More sharing options...
carl_weller Posted August 19, 2005 Share Posted August 19, 2005 My understanding was that canon plans to move to just one pro DSLR, and that it will be FF. The 1Ds mkII would be fine for most with a higher frame rate. If the 5D proves to be true, FF could very well be affordable for serious amateurs within about 2 years and then who needs ef-s lenses except entry-level users anyway? You're right though, there may be an intermediate step of a 1.3 crop 20D replacement before that glorious day dawns :) Link to comment Share on other sites More sharing options...
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