Infrared Photography Help

[photolop]

Hi, I am looking to get my boyfriend a nice gift for his birthday. He is really interested in infrared photography but I don't know much about it.

I am looking to buy him a filter and film (I think this is all he needs?) but I'm not sure which type of filter/film to buy. He has a Minolta XG-M camera. I have found a bunch of infrared films and filters on ebay, but I don't know the difference between them.

I remember him saying something about the film length in his camera being different (it can only take 20 pictures instead of the normal 24?).

Any help would be appreciated! Thanks in advance.

 

[ann]

Check out FReestyle for film, they will have it labeled, with a IR filter there are several options. Look at a 72 which is a good starting one.

 

[TCampbell]

The XG-M is a 35mm camera. That means it needs "135" format film. The film comes in different lengths ... e.g. 135-24 would mean it's long enough to have 24 exposures. 135-36 means it has enough length for 36 exposures. Generally any 35mm camera can handle up to 36 exposures. I've never heard of a 35mm camera that couldn't. The only reason we had film of different lengths is because if you unwind and process the film before you've taken all the shots then you're just wasting your money. I'd typically carry a few rolls of film of different ISOs or lengths depending on the types of events I'd plan to shoot (btw, ISO was almost always referred to as "ASA" back then, but it's the same thing and even the numbers are the same. 100 ASA is ISO 100.)

Regarding film & filters...

We see in the visible spectrum which is "roughly" from about 400nm up to about 700nm. The UV spectrum starts below 400nm and the IR spectrum starts above 700nm.

The R72 filter is so named because it's cut point is 720nm... it blocks visible light below 720nm but allows IR light above 720nm to pass. That really is the critical detail... you need to make sure that filter is an "IR Pass" filter which blocks normal light. Normally when you find a filter labeled as an IR filter, it's an "IR block" filter which blocks IR and allows visible through (the complete opposite of what he wants for IR photography.)

You can also use a Red #25 filter which is sometimes confusingly named an R25 filter. The "25" in this case is NOT referring to the nanometers like it does in the R72 filter. The proper name is "Red #25". The filter blocks blue & green, but allows red to pass and this causes an enhanced effect. This filter can actually be used with normal visible B&W photography (it's not exclusively for IR photography). Essentially if you use IR film with this filter you're allowing more visible light in and this can help show detail in areas that would be black in shadow with IR film using the R72 filter.

BTW, you can also shoot IR film without using any filter at all.

He should experiment with no filter, Red 25 filter, the R72 filter and compare them. He'll see some contrast enhancement with the Red 25 (as compared to no filter) and a very large contrast enhancement if he uses an R72 filter.

There are lots of film choices with different levels of sensitivity. He'll really need to compare for the "look" he wants.

Go check out this site. They have examples of different films as well as examples using those films with different filters (or even no filter.) Snoop around the links on their Infrared section. Digitaltruth Photo: Rollei Infrared IR400 film

 

[photolop]

Thanks for all of your help!

I looked at the link you mentioned, the photos are really interesting. So I think this film should be fine?: Rollei Infrared IR400 - 35mm x 36 exp (2-pack) - Film: Infrared IR400 - Rollei - Digitaltruth Photo.

Regarding the filters, I found a bunch of the R72 and R25 filters on ebay. Do the dimensions for the filters (37mm/57mm/67mm) refer to the size of the lens? If so, I should find out what size of lens he has? Also, I know he has a big lens attachment - so if he has two lenses, the filter size I get him will dictate which size of lens he will have to use for the IR photography?

One last question - does colour IR film exist? I think he was talking about that as well. If so, would it use the same filters?

 

[TCampbell]

Regarding the filters, I found a bunch of the R72 and R25 filters on ebay. Do the dimensions for the filters (37mm/57mm/67mm) refer to the size of the lens? If so, I should find out what size of lens he has? Also, I know he has a big lens attachment - so if he has two lenses, the filter size I get him will dictate which size of lens he will have to use for the IR photography?

The filter size refers to the diameter of the filter. The front of his lens(es) will have threads on them. The filter needs to be the correct diameter to fit those threads. Note that this is NOT the same as the focal length of the lens. For example... my own 35mm film camera has a lens with a 50mm focal length, but the thread diameter is 52mm for this lens. I have another lens with a 24mm focal length, but it's much wider... it has 82mm diameter filter threads.

If any of his lenses have a filter on them now (e.g. it was VERY common for film cameras to have either a "UV", "Skylight", or "1A" filter on the lens) then read the filter as it will probably have it's diameter printed on it.

If he has more than one lens and the lenses use filters with different diameters, you can buy filters in the size needed for the larger diameter and then buy something called "step up rings" to adapt the filter to the smaller diameter lens (it's just a ring with larger female thread on the front and a smaller diameter male thread on the back and they come in lots of varieties based on the size they're adapting from and to.)

As for color IR... I don't know if anyone still makes it. Kodak used to make "EIR" (Ektachrome Professional InfraRed - or just "EIR") but they stopped making it. You can do color IR with a digital camera (the camera usually needs to be converted for IR photography. It's possible to use a non-converted camera but the exposures take much longer because the standard internal filters block most of the UV light.)

 

[photolop]

Awesome, I'm pretty sure he has a UV filter so I will take a look at it.

I found some of the EIR film on ebay but it's pretty expensive (current bid of over 60 dollars), so probably not worth it.

 

[photolop]

So I finally got a hold of his camera! I think the lens diameter is 49mm, but if someone could confirm for me that would be great!

Based off of the 49mm, I found these two filters online...

Red 25 Filter

R72

Could someone take a look at them to make sure they are correct for IR photography?

Thanks so much

 

[KmH]

Yes. The filter thread diameter is 49 mm.

 

[BrianV]

For a film camera: get the Red 25 filter.

 

[photolop]

I was going to go with both filters and this film: Rollei Infrared IR400 - 35mm x 36 exp (2-pack) - Film: Infrared IR400 - Rollei - Digitaltruth Photo

I just wanted to make sure that they are IR pass filters and not IR block.

 

[BrianV]

With the R72 filter: he will not be able to see through the viewfinder to focus and frame the camera.

These pictures are with an R25 red filter on a Monochrome Visible+IR camera. It is basically the same spectral sensitivity as black and white IR film. This is a very old camera.

 

[photolop]

Those are really cool photos. I think he enjoyed the idea of focusing the camera and then putting the filter on and taking the picture.

From what I understand, the Red 25 and R72 filter will produce different results so I was going to get both so he could experiment with them.

 

[photolop]

So the film that I was looking at buying has exorbitant shipping fees.

I have found a bunch of different IR films on ebay, but they have all expired. The sellers have posted that the film has been kept frozen. Are there dangers in buying expired film?

 

[BrianV]

If it was kept frozen- it should last a long time after the expiration date. I gave away my last IR film to a student that bought a Diana from me- was a few years out of date, kept in a cool place. Black and White film usually lasts many years after the "best by" date. Freezing it: even better. Don't spend a fortune on it, but a few rolls to try out should be fun.

Infrared Film was much more commonly used by the technical/scientific field. The switch-over to Digital Infrared by the scientific market really cut IR film sales. If your boyfriend gets into IR in a big way, he will want a converted IR digital camera. These are not too expensive, $500~$1000 gets a mirrorless camera converted to IR, and you can see the image ahead of time. The camera used above is 20 years old, the first-ever commercial IR-Digital camera sold by Kodak. I replaced it with a converted Olympus EP2.

http://www.spencerscamera.com/

 

[photolop]

Great, thanks for the help everyone! I have everything ordered, and hopefully it's all correct.