There is far to much to pass on in a short answer, but I`ll try. I have been doing this for years.
Kodak makes high speed infrared film only once per year in Feb or Mar. Buy early in spring and get the fresh batch that expires the next year. only has a 12 month life in the frig. I suggest B& H in New York City or any reputable high volumn dealer.
M bodies are best as the ir filter is visually opague. Set your M-6 meter to asa100 and meter right through the filter. Don`t forget to meter a mid tone and a tree that has foliage that turns white is not a mid tone. You can also put a 089b gell over the cell of a clip-on meter if you use m2,3,4,p. Again asa 1000-mid tone
I use B+w 092 and 093 or you can cut a kodak 089b gell and put it behind a uv or skylight filter.
You can also use a Leicaflex, SL, or Sl2. Any R series body is also useable, but you must cover the pressure plate with black tape as the dimples will show as a waffle pattern on your best shot- I know. You will also have to shoot from a tripod, removing the opague filter to compose or usr a optical finder in the hot shoe.
All the refles bodies are difficult to laod in the dark, but it can be done.
As far as focus goes, Ihave tried almost every leica lens except the apo ones and I use the same technique. First focus, note the distance on the scale, focus closer until that distance noted is opposite 5.6 on the right hand side of the debth of field scale as seen from the rear of the camera. This has never failed me. If you elect to use a red filter, the infrared effects will be less (wood effect) and the focus may be different. Other films may also be different. This is why Leica does not currently provide a infrared focus mark on their lens. When they did long ago, the ir mark was near 5.6 on the right side. 90 mm colapsable comes to mind. I really like 135 f4.5 and 90 elmar f4 for tele shots. Shorter lenses all seem to be equal.
Shoot a roll in the spring, about 6 frames bracket per subject and record the exposures. After processing you will find the proper exposure for sunlight, now quit bracketing. It is the same just like any other film. You can now go back to the scene and adjust the asa setting so you get the proper exposure by meter and you will never bracket again. Just remember to use proper meter technique like any other film
This answer is getting far to long, but I have tries to cover leica specific practices I use.
Start trying to get your filters now, as the wait may be long.
Ilford sfx 200 is nice, but the ir effects are not as great, but they are adequate if you use bw 092 or 089b gell asa 400 on the meter i think. b+w 093 will record nothing on sfx. Mac0 820 is very nice, but slow. Some place equavelent to a asa3 or 6 speed film. Effects are similar to Kodak, but less grain and halation.
For more generalized information, do a
search on infrared phototography. Also follow the links on each sight. There are lots of sights out there with many portfolios.
Best of luck. The learning curve is tough and can be expensive, but the results are worth it.
