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"Capturing Infrared"

Cindy Flood

Super Moderator
I have a faint hot spot when I use my Olympus 12-40 f/2.8 pro lens on my G1. It is noticible on the raw file, but when I'm finished processing, you don't see it. It is more of a loss of contrast, and only a bit of extra luminosity.
Since the coatings inside a lens can give off IR and cause the hot spot, I imagine that the amount of bright sun would make a difference in the spot effect. If you are not seeing it, I would not worry about it. I will be getting that 16-50mm kit lens in about a week, and I'll try it out on my NEX7 665nm, and let you know if I see it or not in my photos.
 

Uaiomex

Member
I find the kit lens pretty good for such a small "kit" lens. I'd say pretty usable across the range. But it is clearly to see the 50 1.8 is better. The 20 2.8 is better too but less so. If I recall well, you have some Touit glass, right?
Why do you need the kit lens? It nicely collapses when the camera sleeps but it takes time for it to be ready to take a pic. With my Nex 6 it was painfully slow. With the A6000 is much faster to deploy. I could live with it but with the Nex 6 it used to get on my nerves.
Eduardo


I have a faint hot spot when I use my Olympus 12-40 f/2.8 pro lens on my G1. It is noticible on the raw file, but when I'm finished processing, you don't see it. It is more of a loss of contrast, and only a bit of extra luminosity.
Since the coatings inside a lens can give off IR and cause the hot spot, I imagine that the amount of bright sun would make a difference in the spot effect. If you are not seeing it, I would not worry about it. I will be getting that 16-50mm kit lens in about a week, and I'll try it out on my NEX7 665nm, and let you know if I see it or not in my photos.
 

Cindy Flood

Super Moderator
Eduardo,
You are correct. I have the Touit lens and some Leica lenses for on my IR cam. I'm going to get an A6000 to keep in my purse, and I want the kit lens for it.
 

Cindy Flood

Super Moderator
Skies were perfect today for shooting IR so I went to the park with the NEX 5N-IR (720nm) and my new 12mm Touit (I couldn't resist the two Touits deal at B&H). Processed in LR with custom dng WB profile and then RB channel flip in CS6.



Really beautiful photos. Pretty amazing lens, isn't it?
 

scho

Well-known member
One more from today's shoot with the 12mm Touit on the NEX 5N-IR. The relatively compact little 12mm Touit also works nicely on my A6000 and A7R.

 

Cindy Flood

Super Moderator
Eduardo,
I wanted to find out about the Sony 16-50 hot spot. It was reported on Dpreview that the lens is good at f/8, but the hot spot appears at f/16 and f/22. I was wondering what f-stop you used for your test photo?
 
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scho

Well-known member
Eduardo,
I wanted to find out about the Sony 16-50 hot spot. It was reported on Dpreview that the lens is good at f/8, but the hot spot appears at f/16 and f/32. I was wondering what f-stop you used for your test photo?
I just tried the 16-50 pz that came with my A6000 on the NEX 5N-IR and it does hotpot when stopped down below 5.6. LR screen grab below with f/22 in upper left followed by f/16, f/11, f/8, f/5.6, and f/4 lower right. Doesn't get really bad until about f/16.

 
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Cindy Flood

Super Moderator
Thanks, Carl. That is an excellent display of the hot spot. I could live with f/8 or below, but I doubt I will use mine on my infrared camera. I think the two Zeiss Touits will pretty well cover me.

I have over the years found a few lenses that would not go to infinity with my G1 665nm IR. My 50 f/1.5 Contax Carl Zeiss Jena and a Pen 60 f/1.5, among others. That is another thing to watch for when picking lenses for a converted camera. That can vary by individual camera conversions and lenses.
 

Thor Lidasan

New member
Both NEX kit lenses, 18-55 and 16-50 result in hot spots. I've tried to stay below f/8 on the 18-55 and the result is not consistent. It depends on the lighting conditions and angle of the sun on the frame (front and backlighting result in hot spots).

Couple of NEX 18-55 IR:



*

 

scho

Well-known member
Thanks, Carl. That is an excellent display of the hot spot. I could live with f/8 or below, but I doubt I will use mine on my infrared camera. I think the two Zeiss Touits will pretty well cover me.

I have over the years found a few lenses that would not go to infinity with my G1 665nm IR. My 50 f/1.5 Contax Carl Zeiss Jena and a Pen 60 f/1.5, among others. That is another thing to watch for when picking lenses for a converted camera. That can vary by individual camera conversions and lenses.
That is good to know Cindy. I haven't checked with my older MF lenses to see if there any inf focus problems, but will do so before using them. I also did some hotspot checking on the new 32mm Touit and the hotspot is quite pronounced at f/8 to f/22 with my NEX 5N-IR. No problem with the 12.
 

scho

Well-known member
One last 12mm Touit shot from yesterday on the NEX 5N-IR. I did the usual R/B channel flip and then made a duplicate which was toned with my NW profile. I stacked the two images with the R/B color layer on top set to color mode with opacity slider at about 60 % to give this resulting blend. Slightly warmer tones in the tree bark and foliage.

 

Cindy Flood

Super Moderator
That is good to know Cindy. I haven't checked with my older MF lenses to see if there any inf focus problems, but will do so before using them. I also did some hotspot checking on the new 32mm Touit and the hotspot is quite pronounced at f/8 to f/22 with my NEX 5N-IR. No problem with the 12.
Oh, that is too bad about the 32mm Touit. :mad: I have one on the way. The 12, I have used quite a bit on the Nex7 IR with no problem.
 

Cindy Flood

Super Moderator
Very nice, Carl. My favorite thing about IR photography is that you can experiment and get so many different looks. It is always a surprise to find out what you can do with a scene!
BTW, those were some amazing clouds that you had yesterday!

One last 12mm Touit shot from yesterday on the NEX 5N-IR. I did the usual R/B channel flip and then made a duplicate which was toned with my NW profile. I stacked the two images with the R/B color layer on top set to color mode with opacity slider at about 60 % to give this resulting blend. Slightly warmer tones in the tree bark and foliage.

 

Cindy Flood

Super Moderator
Both NEX kit lenses, 18-55 and 16-50 result in hot spots. I've tried to stay below f/8 on the 18-55 and the result is not consistent. It depends on the lighting conditions and angle of the sun on the frame (front and backlighting result in hot spots).

Couple of NEX 18-55 IR:



*

Thank you for confirming this, Thor.

Since hot spots can be created by IR light bouncing off of the internal coating of the lens, I guessed that the amount and angle of the light could make it worse. When I used my Olympus 12-40 f/2.8 pro, I took over a hundred photos and some had the hot spot worse than others (at the same aperture). Funny thing about this all is that my little Panasonic kit lens has always been bullet-proof and my expensive Oly lens has a hot spot. Some Leica lenses were found to have hot spots back when I was shooting IR with a Leica M8. It has nothing to do with the cost or quality of the lens.
 

scho

Well-known member
Very nice, Carl. My favorite thing about IR photography is that you can experiment and get so many different looks. It is always a surprise to find out what you can do with a scene!
BTW, those were some amazing clouds that you had yesterday!
Thanks Cindy. Yes, there are many possibilities with IR, particularly for the newer IR conversions at 590 and 665 nm.
 

Cindy Flood

Super Moderator
Carl, My IR cams are both 665nm. I like the fact that I can put 720nm and 830nm filters on my lens and have those looks, too. Next time, I will go for the Super Color conversion that Eduardo just got on his A6000. Then I would be able to have Super Color, 665nm, 720nm and 830nm with added filters.
 

scho

Well-known member
Carl, My IR cams are both 665nm. I like the fact that I can put 720nm and 830nm filters on my lens and have those looks, too. Next time, I will go for the Super Color conversion that Eduardo just got on his A6000. Then I would be able to have Super Color, 665nm, 720nm and 830nm with added filters.
Sounds good. Do you use Lifepixel for conversion service? My last conversion of the NEX 5N was done by Digital Silver Imaging, but it took quite awhile as they had recently split and moved the conversion service to CA from MA. I may give Lifepixel a try next if you folks think that are doing good work.
 

Cindy Flood

Super Moderator
Mine is from LifePixel. I bought it from Don Libby. He upgraded to an A7r LifePixel conversion. I think that Eduardo had his A6000 done by LifePixel. I will use LifePixel next time.
BTW, LifePixel has a lot of Infrared shooting info on their website.
 
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