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Basic questions qbout IR photography


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Dear menbers

 

I have purchased a B+W 092 IR filter (20-40x)

 

And I have the following questions

 

Exposure: Will the normal TTL metering work for proper exposure when the filter is attached.

 

Focus: How do I focus properly - is the a mark on the lens?

 

Anything else: Is the anything else that I should know or do?

 

Thanks in advance

 

Sincerely

 

Peter

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Peter,

 

I use a different IR filter but:

 

Exposure: Yes, TTL and auto exposure work normally

 

Focus: depends which lens you're using but probably not. Just use a bit of trial and error - I find that most of my lenses work with the focus set at around 5 metres but YMMV.

 

Anything else: if you're tempted to increase the ISO to compensate for low light conditions be aware that IR will produce more noise than visible light photography because of the supressed blue channel, which significantly worsens the signal to noise ratio.

 

Best of luck and please post some images!

 

Pete.

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I have played with both 092 and 093. I prefer the 093 personally, because the 092 seems to give me 'only' red colours - even after white balancing, whereas the 093 seems to give me other colours (after white balancing). If Iam doing something wrong let me know!

 

However, as farnz said, auto exposure generally works OK - and at least gives you a good starting point from which to experiment.

 

Focusing can be a bit hit and miss, but generally I find the rangefinder to give a good approximation, and you can adjust from there based on the aperture you are using.

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IR pictures do usually look best in greyscale, IMO. We do not see any 'infrared colour' after all. For greyscale IR I prefer the 092 filter. Note that resolution does suffer a bit at these long wavelengths, which the lens is not corrected for, and the image can do with a bit more sharpening and contrast-upping than normally. The slight loss of sharpness does mean that you will not lose a great deal by using the JPEG format.

 

We have had IR film before, but handheld true IR photography is really a new game, and a fascinating one.

 

The old man from the Age of Glass Plates

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What everyone above says. I use TTL and focus by transferring the rangefinder distance to the f5.6 setting on the right of the lens as you look down.

 

5.6 is a good start, but some lenses will work better at 8, 11 etc. I bracket-adjust if I have the time and magnify-chimp in B&W mode. By using a smaller stop to take the shot much of the focus shift is taken care of depending on lens; much less to worry about with wide angles such as the 24mm.

 

The 092 cuts off at shorter wavelengths so the exposure factor is not as great, it may be possible to hand-hold an 092 shot and not an 093 shot. I frequently push the ISO to 320 or 640 to enable this too. There is a range of IR filters available from various sources, the different Wratten numbers will produce different results especially in color. Results also vary by sensor and lighting condition. There is a lot of room for experimentation.:p:P

 

The attached picture was shot with a 35 1.4 Asph and Hoya IR filter hand-held at 1/20 (note blurred truck). Aperture not recorded. I got the infinity focus OK but not the sign at ISO 320 :eek::eek:

T

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IR pictures do usually look best in greyscale, IMO. We do not see any 'infrared colour' after all. For greyscale IR I prefer the 092 filter. Note that resolution does suffer a bit at these long wavelengths, which the lens is not corrected for, and the image can do with a bit more sharpening and contrast-upping than normally. The slight loss of sharpness does mean that you will not lose a great deal by using the JPEG format.

 

We have had IR film before, but handheld true IR photography is really a new game, and a fascinating one.

 

The old man from the Age of Glass Plates

 

Lars is right that greyscale does look best, but playing with colour can be interesting:

 

L1000051.jpg

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I've been using the 093 filter, set ISO for 640 more or less, manual white balance on the grass and transfer the in focus point so it appears opposite the following settings on the DOF ring.

 

15mm CV between 4.5 - 8.0

28mm CV 4.0

35mm Summicron ASPH 5.6

50mm Summilux 8.0

 

Using those IR focus points seem to result in reasonalbly sharp photos.

 

I convert in CS1 and adjust exposure, white point and black point, as necessary. I like to preserve the color cast rather than converting as grey scale.

 

Recently I've experimented with the 50mm in an effort play with aperature and DOF.

 

526jgqd.jpg

 

505hwzb.jpg

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Summarit 1.5/50, vintage 1954

 

Interesting that it transmits UV, what sort of IR blocking and UV transmitting filters did you use? :confused: I have shot the same lens in IR using the Leitz IR filter made for the lens's filter mount, which as you know is odd-sized. I have gotten good UV with the Nikon UV lens, their UV filter plus, the B&W 489 to block the IR.

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Interesting that it transmits UV, what sort of IR blocking and UV transmitting filters did you use? :confused: I have shot the same lens in IR using the Leitz IR filter made for the lens's filter mount, which as you know is odd-sized. I have gotten good UV with the Nikon UV lens, their UV filter plus, the B&W 489 to block the IR.

 

B&W 403. It must be about the last Leica lens to transmit UV, later lenses all use Absorban kit or UV blocking coatings. Another good UV lens seems to be the Jupiter.

 

L1000086.jpg

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B&W 403. It must be about the last Leica lens to transmit UV, later lenses all use Absorban kit or UV blocking coatings. Another good UV lens seems to be the Jupiter.

 

 

Thanks, I shall have to experiment! :D

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B&W 403. It must be about the last Leica lens to transmit UV, later lenses all use Absorban kit or UV blocking coatings. Another good UV lens seems to be the Jupiter.

 

The inofficial word from Leica (as I understood it) was that only lenses from 1960–62 or so blocked UV. So that means that early Summicron lenses should transmit UV.

 

The old goy from the Age of Visible Light

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