Discussion in 'General Equipment Chat & Advice' started by Stephen Rundle, Jul 5, 2020.
I have forgotten which filter to use with IR film.
720nm (R72 is Hoya's specific name for this type) is the standard for black & white IR, but slightly longer wavelengths can also be used, generally giving sharper images (if static & well focused) but at the expense of longer exposures. Likewise more permissive filters can be used for shorter exposures & a more dreamy soft focus look. I've seen reasonable results from dark red, red & even orange filters. The increased/reduced blur in these cases is down to the focus shift of lenses when used for NIR so will vary with the lens.
Colour IR film has a wider range of filter effects that probably could fill a book on their own if my digital IR is anything to go by! Perhaps this is why my books on IR photography don't even try to cover it.
IR film doesn't see as far into the IR as converted digital cameras. Digital goes to ~1050nm while film tends to be only to around 800nm - 900nm (highly dependent on the film).
I often prefer to use the B&W 092 , which IIRC passes light from about 680nm rather than 720nm .
The result is more detail is captured due to the slightly lower contrast .
What film are you using ?
I like the Rollei IR 400 , it's quite a bit more IR sensitive than the Ilford SFX . Metering I use a spot meter on such as a rock at ISO 6.
Thanks all, appreciated have ordered this to try out
I'd be more inclined to cancel that order .
Only the 720nm one is really useable with modern IR film .
The other three are really only for infrared converted digital cameras .
There also of quite poor quality and the images are quite degraded . At £7 each rather than £50 or so each , you can't expect much .
You would be better looking for a used Hoya or Kood r72 if you want to keep the price down while you try it out .
You'll find one of them for less than the Neweer ones but get better results .
OK done, Thanks
Looking on Ebay now
I love Ebay
I've found the various budget ones ideal for trying different wavelengths. there's no significant spectral difference with them, & optical quality MAY be inferior but it's certainly not bad.
I tried to cancel the order but too late coming tomorrow so I'll try them
The cheep ones I tried years ago gave results like they had had some scrunched up cellophane lay across them !
Try them first , if it's from Amazon you can still send them back anyway .
Try them on one of your digital cameras , with a bit of luck one of them see infrared better than the others .
Do it on a tripod and if the image is bad , get rid of them .
it's those pesky little decimal points that are the problem !
I have saved a search on ebay for the one you suggested Hoya
I will try the filters and post the results
Now I have to figure out the exposure for the filters
Which film are you using ?
Blasted good question I'll look in the fridge later
Probably my favourite emulsion , especially in large format .
With an R72 filter , you expose it as ISO 6 film .
You need to take a meter reading off something like a weathered rock .
Grass and green broad leaved tree leaves reflect a lot of IR light compared to stone , same as taking a shot of a snow scene .
So throws your metering out .
If you haven't got a spot meter , or your camera doesn't have an ISO 6 setting ( it won't ) set the camera's ISO to 100 .
Without the filter on , take a meter reading .
For every stop down of ISO to get it down to 6 , you need to drop the shutter speed by the same amount if stops .
So ISO , 200 , 100 , 50 , 25 , 12 , 6 .
Most shots taken on a sunny day are often around 1/125 sec , so with a rangefinder camera you can still shoot handheld .
I often use a Minolta Dynax 9 , with a separate viewfinder on the hotshoe to compose with , the filter on the lens , I can trust the AF to do the job .
I have the cameras ISO set to 320 , and the metering threw the filter gives me correct exposure.
Whether you camera would behave the same j don't know .
Regards exposure , some scenes behave differently , so sometimes need more or less exposure.
You just need to get used to the film .
Practically all the photos in this album where via cheap filters - mainly Chinese ones ex e-bay or bare 25mm technical glass for some of the more unusual filters. there are couple of homemade filters too (floppy disk media & negatives)...
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