Infrared filter (not completely dark)

[Marco Gilardetti]

Good afternoon gentlemen.

I have recently bought an IR film (the Efke one) to give it a try before this product disappears. My intention is not to get "special effects" but to penetrate the fog of distant landscapes.

I understand that a dark red filter is not enough to actually have a proper IR anti-fog effect. However, I fear that a full IR filter would be too dark to be used with a reflex camera.

What type/number of filter can I use to get a good anti-fog effect, with still enough vision left in the finder to be able to frame and focus the image correctly?

 

[Mike1234]

Maybe a Wratten #72 (extremely deep red)... actually an IR filter that passes near IR. There's also a #29 (very deep red). If I was attempting your goal I would try the #29.

EDIT above... typed #29 twice but the near IR should have been a 72!!

 

[keithwms]

Yes, a deep red filter might do it for you. But honestly you won't get as much haze clearing effect as you would with something much deeper like an rm72 or #87. But instead of composing through the filter, why not just compose (using a tripod) and then put the filter on.

Overall, the obstacle of composing through a filter is why I prefer rangefinders for IR.

 

[colrehogan]

You will probably need at least the 72 filter mentioned by Mike above. A tripod is usually recommended when shooting IR because of the longer exposure times that these filters cause. Also, it allows you to remove the filter without losing your composition.

 

[Sirius Glass]

Yes, a deep red filter might do it for you. But honestly you won't get as much haze clearing effect as you would with something much deeper like an rm72 or #87. But instead of composing through the filter, why not just compose (using a tripod) and then put the filter on.

Overall, the obstacle of composing through a filter is why I prefer rangefinders for IR.

One of the clear examples of an advantage over slrs.

I have used rangefinders. I have one. I usually use slrs.

Steve

 

[DaveOttawa]

...But instead of composing through the filter, why not just compose (using a tripod) and then put the filter on.

This is the way to go, Efke IR is a very slow film so you are almost certainly going to be shooting on a tripod if you want a sharp negative anyway.
Then you can use whichever filter you want including the 89B opaque (almost) ones.

 

[Mike Richards]

B+W Filters

Marco,
Since you are in Europe, the German B+W filters might be easier to come by. The opaque 093 is best, but you can get some acceptable results with the 092 deep red. I agree with the comments about using a tripod; 093 and tripod will provide the sharpest images.

 

[Mike Richards]

PS if you are really interested in sharpness, you will want the Efke IR with anti-halation layer. I assume it's like the old Maco 820c. The layer washes off in a minute with water before developing, but is difficult to load on plastic reels from the outside in. I always used steel reels, so no problem.

 

[EASmithV]

Good afternoon gentlemen.

I have recently bought an IR film (the Efke one) to give it a try before this product disappears. My intention is not to get "special effects" but to penetrate the fog of distant landscapes.

I understand that a dark red filter is not enough to actually have a proper IR anti-fog effect. However, I fear that a full IR filter would be too dark to be used with a reflex camera.

What type/number of filter can I use to get a good anti-fog effect, with still enough vision left in the finder to be able to frame and focus the image correctly?

If you are trying to pierce the fog in the distance for landscapes, you can probably just focus your camera to infinity and not have to worry about framing. However, if your camera does not have an external viewfinder, you may have to take the filter off to compose.

I wouldn't worry about focus too much.

 

[Sirius Glass]

If the moisture content of the fog is high, which it probably will be, the filter will not matter. Water [and Carbon Dioxide] attenuate infrared light in many wavelengths. It will be interesting to see what you get. Would you post pairs of photographs, one with visible light and one with the infrared when you do this experiment?

Steve

 

[DaveOttawa]

If the moisture content of the fog is high, which it probably will be, the filter will not matter. Water [and Carbon Dioxide] attenuate infrared light in many wavelengths. It will be interesting to see what you get. Would you post pairs of photographs, one with visible light and one with the infrared when you do this experiment?

Steve

I'm no physicist but I suspect atmospheric haze that the OP is trying to penetrate is caused by scattering not absorption of the light; scattering is more pronounced for shorter wavelengths hence the ability of IR radiation to penetrate haze better than visible radiation. It would follow that the longer the wavelength the OP can use for photography the less the haze would record.

 

[2F/2F]

When using filters that will give the most IR effects, you cannot use generally-accepted hand holdable shutter speeds with this film, nor can you look through the viewfinder to effectively compose. That is one of the reasons why HIE was such a great loss. It got a fairly heavy IR effect while hand holdable using a #25 filter, and also allowed a viewable composition through the filter. I prefer to use this film on a TLR so I am not always having to move the filter on and off. For 35mm, I prefer Rollei IR. You should try both of these emulsions while you are at it. Be sure to shift focus so that the IR light is better focused. Yes, it does make a difference with these films IME.

 

[EASmithV]

Would you post pairs of photographs, one with visible light and one with the infrared when you do this experiment?

Steve

Please do!

 

[keithwms]

If the moisture content of the fog is high, which it probably will be, the filter will not matter. Water [and Carbon Dioxide] attenuate infrared light in many wavelengths. It will be interesting to see what you get. Would you post pairs of photographs, one with visible light and one with the infrared when you do this experiment?

Steve

The scattering is primarily Mie scattering.

Anyway, an example of "haze clearing" (and Wood)...

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I don't have the unfiltered neg scanned, but it is much hazier over the horizon.

 

[Mike Richards]

Infrared can indeed pierce haze. I have an example you can check here: Zugzpitze. The images are digital, but the principle is the same.

 

[Marco Gilardetti]

Marco,
Since you are in Europe, the German B+W filters might be easier to come by. The opaque 093 is best, but you can get some acceptable results with the 092 deep red. I agree with the comments about using a tripod; 093 and tripod will provide the sharpest images.

Good morning everybody.

Thanks Mike, you were right and as a matter of fact I ended up buying B+W 093 and 092. One at a decent price, the other at an outrageously high price.

I did some experiments towards the end of summer with Efke IR (outrageusly highly priced too), but the guessed ASO ratings I've seen here and there on the net are ridiculously high if you ask me. I guess it's more in the 50 ASA (with no filters) range after experimenting with it. It's simply pathetic how the film doesn't come with any exposure and development data.

The fact that the filters don't come with an exposure guide is pathetic in its turn either. Overall this has been an extremely frustrating and expensive experience. And please note that I consider myself a very experienced photographer, with a top scientific background due to my education. I'm still much oriented to experiment more, but I wonder how many people are so hardcore fans to photography as I am; the whole matter is ridicolously frustrating BECAUSE producers want it to be so, and frankly speaking if these products would totally disappear from the market due to poor sales it would be VERY WELL DESERVED.

I have now to wait until next spring and my next postal order, as these films are no longer available anywhere in shops in my area (go figure). I will post the results if I get anything decent, but quite obviously it will be no earlier than 6 months or so.

Thanks for reading, have a nice day!

 

[David William White]

Data Sheet: http://www.freestylephoto.biz/pdf/MACO_IR820c_AURA.pdf

When I first attempted Efke ir820, I did it with roll film, set up a scene, then bracketed aggressively all the way down to ISO 1. (I was using the Lee IR filter.) Just needed one roll. That gave me good data points so I could reliably shoot sheet film.

 

[thefizz]

There is no need to adust your focusing if using a #25 filter as there is still a lot of visible light reaching the film. My understanding is that the IR focus marks on your lens are usually calibrated for 800nm, which you won't be recording much of. The focus shift is really only required for a particular film and filter combination which would be recording light close to 800nm.