Infrared b&w film overexposed

[mcsimard]

Hi, I was in Maine last week taking shots by the ocean with Kodak

high speed infrared film (HIE)and a red filter no 25. I followed the

kodak instructions and set the iso at 50. The whole roll is

overexposed. Why do Kodak suggest such a low ISO? Any comments

regarding exposure with Infrared b&w film will be greatly appreciated.<div></div>

[bruce_karnopp1]

Infrared film is tricky at best. Your meter probably does not read that part of the spectrum. You should check out the homepage below:

www.davidromano.com

 

David has a great deal of information about shooting Kodak, Maco, and even the Konica 750 film. He also sells a modified Minolta meter for infrared readings.

 

ISO 50 with a #25 filter seems too low. The Kodak film isn't call HS = high speed ... for nothing.

[ronald_moravec1]

I use 1/250 at 6.3 with an IR filter (B+W 092). I set the meter t0 800 and meter right thru the filter.

 

50 would be correct if you did not meter thru the filter (400 less three stops for the red is 50). Every meter/camera is different so you need to establish the correct meter setting. I personally never found a hand meter or camera meter that did not work at 800 or 1000 if you meter thru the 092 filter. The film is really not 800, but then again the meter is not designed to read IR either.

 

Never use new equipment on vacations. Get the bugs out at home.

[jay ott]

You should be bracketing your shots in full stops. How long was your developing time? I think Kodak times are too long. I use stock D76 for about 7.5 minutes.

[mcsimard]

Bruce, thank you for your valuable info.

 

Ronald, I DID measure through the filter. Should I first measure the light, than screw on the filter without opening 2 stops? Thanx.

 

Jay, I used stock d-76 for 9 minutes at about 74 degree farenheit.Is my film overdeveloped? Thanx for commenting.

[hilander]

I rate HIE @200 in bright sun and bracket. It eats up the roll 3 times as fast, but

I always get a printable exposure.<div></div>

[david_elden]

I have shot HIE with a Nikon F601 & FM2 using a Cokin red filter (very similar but not identical to Wratten 25). Personally I set the camera ISO to around 400 for sunny day work outside. Having said that I don't pay a lot of attention to the meter reading if it's "sunny 16" conditions, I do if it gets a bit overcast or there is a lot of shadow area in the shot.

Dev in D76 stock per Kodak instructions. This gives highlights which aren't entirely blocked up and retains some shadow detail - but I find I print at higher contrasts and have to dodge the shadows a fair bit to keep detail there. Negs look thin but I like the prints.

Like you I found the Kodak instructions give negs too dense for my taste. I know other photogs who have observed the same thing.

It seems to me that HIE has relatively little latitude compared to most B&W films and this combined with the non-standard sectral response (doesn't match the camera meter) means that more exposure experimentation is needed than with most films. So you will have to plan on using a roll up in bracketing (suggest ?two stops range) and decide what YOU like. This will "waste" a lot of frames on that roll but that's the last roll you will "waste"

If you can find this book in your local library it's the best "how to" on HIE I have seen: "The Infrared Handbook" - Laurie White - pub. Amherst Media.

[kaiyen]

<p>Marie-Claude,

 

<p><i>Ronald, I DID measure through the filter. Should I first measure the light, than screw on the filter without opening 2 stops? Thanx.</i>

 

<p>You <u>either</u> set it at 50 and meter without the filter, or set it at 400 and meter it with the filter. A red 25 is worth 3 stops of light loss, so it's effectively the same. Therefore, what you did resulted in a 3 stop overexposure.

 

<p>Keep in mind that 400 with the filter is just a starting point. Many default to the sunny 16 rule, others have come up with a variant of that, etc.

 

<p>allan

[rustys pics]

With a red (Wratten 25) filter, HIE clocks in at least ISO 400 with TTL metering.

See this recent <a href="http://www.photo.net/bboard/q-and-a-fetch-msg?

msg_id=00CVaj">thread.<a/>

Many will tell you the meter cannot read IR. This is true, but with HIE and red 25 filter you're

not catching much real IR, mostly Near IR, which is all you need for pictorial purposes and the

glowing "Wood Effect".

[jay ott]

Marie,<p>

 

Yes, I think it's overdeveloped, especially at 74 degrees. Try 68 degrees at 9 minutes and you should see a difference. If you don't like the results cut your time down another minute. Unlike regular b&w, HIE is best shot when the sun is high and on days with big white puffy clouds.

[mcsimard]

Thank you everybody for all the valuable comments. Asking question on this forum is certainly a great way to learn!

PAT, did you use a red filter for this picture?

 

Anybody can tell me what does a red filter do to the picture (combined with HIE)? does it make it grainier? Thanx.

[kaiyen]

The red filter cuts out the unwanted light wavelengths. You want the red and infrad range, so you use the red filter to eliminate the blue end of the spectrum. In other words, you are maximizing the amount of exposure due to red and infrared wavelengths.

 

HIE is pretty grainy by itself, though you can control that somewhat with developer choice. I use Rodinal which makes for a grainy but very sharp print.

 

allan

[rustys pics]

You can actually get some decent grain out of Kodak HIE if you process it in Microdol-X

undiluted for 17 minutes. Also, you may try using a #29 red filter. It cuts a bit more blue

light and enhances IR contrast, but you can still see to focus.

[chris_waller]

You say you set the ISO at 50 - was that on the camera or on a hand-held meter? If you are using the camera's TTL meter then you should set the ISO dial at 400 ASA. The cameras meter will compensate for the red filter automatically. BUT, if you use a separate, hand-held meter then you would set that at 50 ASA because it would not be reading through the filter. In any event, if you use the camera's TTL meter, ensure that it compensates accurately for the R25 filter. Some camera meters are red sensitive and cause under-exposure. When I shoot IR I use a hand-held incident meter.

 

The purpose of the R25 filter is to cut out the blue-green end of the spectrum which would otherwise mask the IR effect.<div></div>

[nate_ross]

I have had great luck shooting HIE rated at asa125, metering with a handheld meter, no compensation for the filter, which was a red #29, shooting under studio strobes. developed in ilfotec hc, standard dilution, I forget how long, but it was whatever digitaltruth said.. the grain was a bit much, but the exposure was dead-on. Didn't need to bracket.

 

Now if only we could get enough people together to buy a custom batch of HIE in 4x5.

[hilander]

Hi Marie-Claude,

Yes, I used a red #25 filter. Allen and Chris did a great job explaining the

effects of the red filter. I developed this with Rodinal 1:50 @ 68 degrees for 10

minutes.

[kaiyen]

Pat,

 

I got a question for you. When you rate at 200, this is with the filter on? Because that would strike me as awfully overexposed.

 

On the other hand, I am often forced to rate my film at least at 800 or even 1200 in _bright_ sun to keep from massive overexposure. So perhaps you mean you rated 200 without the filter?

 

fun stuff, this rating HIE discussion...

 

allan

[michael_riggs]

The only time I've exposed HIE according to instructions turned out worse than that. So I don't. I rate it at ISO 200, use a #25 red filter, set at f/8 and meter shutter TTL. Have filter on when metering/shooting. Tripod and cable release (highly) recommended. I suppose the reason for Kodak's low ISO recommendation is because that's how the math works out. A #25 red filter reduces the exposure by 3 stops. A 200 ISO film taken down 3 stops makes for IOS 50 exposure. Works on paper, not in reality. Sort of like Communism.

[michael_riggs]

Correction on last post---ISO 400 minus 3 stops = ISO 50.

[john carter]

Marie-Claude,

Look at a scene that you would consider 'sunny 16' and if it has a lot of green and bright sun. You expose it as if it was the old snow and/or sun which is f22@ 1/ISO. If you have sun and half shade then you use 'sunny 16.' For me that is f11 @ 1/250 for all sun, Red filter in place. Or f11 @ 1/125 for sun and shade, Red filter in place. Overcast and interiors @ f8/11 @ 1/60 Red filter in place. No metering required. Develope D-76, 68 degrees, eleven minutes. I got this formulas from a retired Doctor in England and it works. In California some times if it is especially rich in IR I go to f16 @ 1/250, with filter in place.

[mad1]

HIE 25iso in X-tol (I'm pretty sure for the dev) it'S a 3 years old picture...

 

http://www.photo.net/photo/4552264