Archived posting to the Leica Users Group, 2016/09/01
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Great shots Ken! My favorites are ?Central Oklahoma?, ?Taos pueblo?, ?Mission San FRancisco?" Lluis > El 1 set 2016, a les 17:33, Ken Carney <kcarney1 at cox.net> va escriure: > > Hi Howard, > > Yes, that is correct. In my initial tries with digital IR I thought a > wide-angle at infinity would make things simple, but as you note there are > different infinities for the wavelengths. With regard to autofocus, I > can't offer a technical explanation. Since the autofocus is based on > contrast differences, I just assume those work as well in the IR as they > do in normal light. Here is a more complete explanation from > Lifepixel.com: > > https://www.lifepixel.com/focus-calibration-options > > Here are some samples mostly all taken with the Fuji XE-1 or XE-2 and a > Hoya R72 IR filter (and autofocus): > > http://www.kencarney.com/infrared > > The Fuji cameras have a weak IR filter. The downside is long exposure > times and a tripod or monopod (as much as 1/2 second). I will probably > soon have a third Fuji XE body which I will probably have converted to IR > only, and take advantage of normal exposure times. > > Ken > > > On 8/31/2016 8:24 PM, Howard L Ritter Jr wrote: >> Ken? >> >> If you think you can't focus IR because you can?t go beyond infinity, >> you?re going in the wrong direction. IR focuses as though the subject is >> CLOSER than it is, so you want to use a DOF marker that focuses the lens >> at a shorter distance than the subject actually is. For my lens (same as >> Tina?s) the best ?distance" for a subject at infinity is 2-3 meters. Even >> there I can?t get as sharp an image as with visible light. >> >> No, this 21mm f/2.8 Elmarit doesn?t have an IR index. I?ve seen them, and >> would have sworn that my older Leica glass did, but not so my vintage 50 >> ?lux, DR ?cron, or 5cm ?cron. I have no idea where I used to see them, >> but clearly IR is out of fashion now. >> >> I?m intrigued to hear that you can get properly focused IR images with an >> AF lens. Are you shooting digital? I?d have thought that the IR filter >> routinely used as a sensor cover glass in digital photography (except for >> the M8!) would have prevented this. Or are you using film? If digital, >> what camera? And what filter are you using? >> >> ?howard >> >> >>> On Aug 31, 2016, at 8:50 PM, Ken Carney <kcarney1 at cox.net> wrote: >>> >>> Looks like you're pretty close. I think the key to IR is autofocus, not >>> an option here. You might try a few shots at different focus settings >>> to see what works with the M8/21. I know my Fuji X 14mm is OOF when it >>> is at his hard stop infinity setting, with a 720nm filter, but autofocus >>> if fine. Also in LR I like to pump up the whites and decrease the >>> blacks some. It is great that you can make IR images at those settings, >>> freeing you from the tripod. I take it that the 21 does not have an >>> "infrared" focus mark? >>> >>> >>> On 8/31/2016 6:49 PM, Tina Manley wrote: >>>> LUG: >>>> >>>> After seeing the great IR photos posted here lately, I finally dug out >>>> my >>>> old M8s (the ones that fell in the river but are still working fine), >>>> charged up the batteries, and found a B+W 092 filter in the drawer that >>>> fit >>>> my 21/2.8 Elmarit. I went out around the farm and photographed a few >>>> things. Lots of problems. Nothing looks sharp. What am I doing wrong? >>>> None of the EXIF is right. Most of these were made at ISO 160, around >>>> 5.6, >>>> and usually 1/30 or more exposure. >>>> >>>> http://www.pbase.com/tinamanley/image/163998663 >>>> >>>> and the next 5. Is there a trick to focusing with the dark filters? >>>> I do >>>> like the tones so I would like to learn how to do this, but it has to >>>> be in >>>> focus to work for me!! I got some great photos of the cat yawning that >>>> are >>>> so out of focus I won't bother to post them!! >>>> >>>> TIA >>>> >>>> Tina >>> >>> _______________________________________________ >>> Leica Users Group. >>> See http://leica-users.org/mailman/listinfo/lug for more information >> >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for more information > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information