The Tri-Elmar classic has no hotspot at any focal length. Infinity focus at about the f4.0 depth of field mark.
Just got Avenon 21mm f2.8 from Japan (i think it was branded in US a Kobalux)
Became my favorite lens for IR work, no hot spots or flare
here is a sample
Calchaquíes Valley, Salta Argentina (infrared)
Here's one with the CV 15/4.5 Superwide @ f4.5.
I just held my 52mm Hoya R72 over the lens. Wide open = no hot spot:
Last edited by Lloyd; 5th March 2009 at 15:41.
What I am finding both from my brief experience with the M8 and Hoya R72...is that with the R72 specifically, one cannot get the "white trees/blue skies" effect that Carlos was able to demonstrate. Carlos, I presume you got that effect (the one you showed in your two posted images) from your B&W 092 filter, not R72. It seems for false color IR, the B&W 092 lets in far more visable light (along with UV) than the Hoya R72. With the R72, color images are predominantly red/magenta and no amount of photoshop adjustment so far has been able to give me blue skies (and magenta or white leaves)...nothing even close. Both filters are excellent for B&W IR, with the R72 having a bit stornger effect. B&W's 093 filter lets virtually no visable light in...so almost no false color with color IR images...but sticking black skies with B&W IR.
Carlos (and anyone else)...have you been able to get blue skies/white leaves effect with the M8 and R72...or just using a B&W 092 with your M8?? I want to confirm this. Thanks!
Here is why "hotspots" are there:
Check your lenses under IR light and it will easy to figure out which one to use and which one to avoid.
Summilux 35 pre-asph - no hot spot w/ R72.
Does temperature affect the images with say an M8, tungsten WB setting, and a Hoya R72 filter, on a lens without hot spots?
For example, say a landscape scene with both live and dead foliage, sky is exactly same grey. Would a temp of 10 deg. F look different than one at 30 deg. F. assuming moisture levels are the same?
I just received a Zeiss 25mm f2.8 Biogon for my M8.2. I tested it with my Hoya R-72 Filter. No hot spot. Very sharp at f5.6. Excellent results at ISO 320 +2/3 EV.
Cv 35mm Nokton f/1.4 MC has a hotspot @ f/8. I will have to try at more wide open settings. Still it is very manageable.
Carlos, that is a beautiful image. How is the IR mark on the CV 35, or is there one? I've found the IR focusing marks on the Canon 28/2.8, and Hexanon 28/2.8 to be very accurate with the R72 filter.
It's actually pretty mild, but there nonetheless. I find it less noticeable with a B&W 092 vs a Hoya 72 despite that those filters are supposed to be identical. (yes, I have both filters) The lens does not have an IR mark so i guesstimate using the right f4 mark on the barrel.
I would love to see how bad some of the hotspots are, particularly 18mm distagon, 35 lux asph and 50/1.5 sonnar. Otherwise I'll post when my IR filter arrives next week.
No hotspot with the 50 Sonnar wide open.
No hotspot with the 50 Sonnar at f/5.6:
Who did the original tests?
18mm distagon certainly has a hotspot around f/11. Closer to wide open not really an issue.
Anyone tested a CV 28 3.5 lens for hot spots ??
Seems like a perfect compact kit on a M8.
Here's a ZM 35 f/2.8 C-Biogon, no hotspot. The colour shift is from manual WB and in-camera jpeg.
The 18mm Distagon doesn't have a hotspot. It does however, have some crazy internal reflections I could really do without! I'm going to test various apertures and see if it's not evident at any particular setting. It's probably fine on the M8.
This is at f/11 on the M9
The 25mm Biogon on the other hand is causing some intense internal reflections! I don't know if this is because of the non-multicoated filter I'm using, but given that it's quite rectangular I'd say it's bouncing off the sensor at some stage. The problem gets worse stopping down, this is at f/8.0:
I have the hood on the lens, and no light is hitting it at an extreme angle. I even tried further shielding the lens with my hand but no go. It also occurs regardless of what direction I'm shooting in relation to the sun.
The reflection itself is normally blue, I just have a channel swap as part of my post processing for IR.
My 25mm Biogon is faulty, I've now tested it with an 8s exposure with a lens cap on while turning it around under bright sunlight and I get the exact same shaped flare however with the rest of the image being black. Off to Zeiss it goes I guess.
Last edited by thrice; 19th April 2010 at 19:39.
28mm/2.8 Elmarit ASPH *
50mm/2.0 Summicron IV (tab version)
* Hot spot only showed up on one image when shooting into the sun at f/22. All other images were fine in normal circumstances.
B+W 39mm 092 F-Pro
CV 25/4 snapshot skopar (ltm)
Leica 40/2 Summicron-C
Filter used : R72
Leica Summicron-C 40/2 , M8 R72 . 32s f16 . No hotspot.
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canon 50 f1.2 (ltm) hotspot visible at smaller apertures (f8 and smaller )
The little CV 25mm f/4 Skopar used to be my favorite lens for IR on the M8.
Last edited by scho; 13th April 2012 at 05:44. Reason: typo
Very kewl, Carl. Love that one. Was this taken with the M8?
Canon 50mm f1.2 LTM (at f22 or f16) -- obvious hotspot.
Not so obvious from f1.2 to f8.
35 lux FLE definitely has a hot spot.
21/3.4 Super-Elmar does not.
I get a hotspot most of the time when using my CV35/1.4 Nokton MC and a B+W 092 filter