bill_taylor2

I've read through a ton of IR film guides and I still have one basic

question. Assuming I know what developer I want to use, and that I

have selected a film to use, and I've picked a filter to get a

pleasing IR effect, how do I determine what ISO to use when metering

the scene?

I've seen two methods tossed back and forth, and sometime

intermingled, and it confuses the heck out of me. One says to just

set the meter for the unfiltered film speed, then meter and use the

filter factor. Others say to set the meter at the unfiltered film

speed then meter through the filter. Still others say to correct the

film speed by the filter factor then meter. And sometimes they say

meter with the filter on even after correction! And of course

everyone says to bracket, bracket, bracket.

Back in vocational photography, they told us to bracket too, but to

use your head. Try to know (or estimate) what side of the "true"

exposure you are on and that way you can bracket in roughly the

correct direction (0, +1, +2, +3, etc.) Of course there is nothing

wrong with bracketing the traditional way (0, -2, +2, -4, +4)

either. But I was hoping to use at least a small amount of science

and not so much guesswork in the process.

Anybody out there know the TRUE answer?

thanks,

Bill

ps. Anyone know of a light meter that has IR sensitivity? My Gossen

Luna-Pro seems to have some, but I'm not sure. The quickie test is

to point an infrared remote at the meter and see if it responds.

Mine does, but it doesn't really give a reliable reading.

I'm curious about center filters.

When do I need them? How bad is the problem? and What if I don't

use them?

Are they brand specific? Rodenstock filters won't work correctly on

Schneider, for example. In particular, I've heard that Nikkor lenses

have very even illumination across their image face and do not need

center filters the way otehr lenses do. Is it true?

thanks in advance for clearing this up,

Bill

I made up an Excel table of hyperfocal distances, based on my lenses. I got the formula from the Kodak Large format guide.

Just in case it is confusing, the numbers are in milimeters to the subject. So divide by 1000 to get meters. And, for the mitpickers out there, including me, the tables also give distances for different film resolutions, assuming the circle of confusion is at the resolution limit.

Hope it is not too hard to understand. Any questions, let me know.

bill

Alan,

I had exactly this same problem and posted a similar question to this board a few months back.

My solution was to CAREFULLY grind off the tab with a Dremel tool. I checked and double checked exactly how much needed to come off, then got a grinding tip and went to work. BIG MISTAKE. The back is made of aluminum and I was using a ferrous grinding tip. The result was that the grinding tool clogged with aluminum bits and stopped cutting well.

Regrouped and changed tips. High speed steel with diamond grit, small diameter (1/8 inch). That worked fine, but it was slow work. Which is good because you definitely do not want to go too far, too fast. Just remember to check the fit often and try to keep the finished surfaces flat and square.

One other thing, I sucked up the chips as they were being made. This way, you don't have them obscuring the area you are trying to see, and you don't have to deal with metal filings in the camera or the film plane later. I used the vacuum hose attachment on my Kirby, duct taped to the work surface so it would not move around and I would have two free hands to work with.

It is loud work, between the vacuum and the dremel, so you might want earmuffs or plugs. And there are chips flying, so you will definitely want safety goggles/glasses. By the time you're done, you'll feel like a machine shop foreman!

Everything fits great now, and no light leaks. Just remember to cut the bare minimum necessary. And if you find a good coating to repaint the cut area, let me know. :-)

good luck,

Bill

I took Dhananjay's advice and went with a T-shirt. Went down to my local t-shirt shop, got the cheapest ash grey and black X-Large shirts they had, $5 total. I put the black inside the grey, then went to the alterations shop to have the two necklines sewn together, $12. While she was at it, she threaded a bootlace into the neck, like a drawstring. Add the springloaded keeper and the cost of the bootlace, $3. Total of $20, plus tax and driving around.

I just used it today to shoot some climbing ivy in the backyard. Put the neckhole completely over the back standard and tighten the drawstring. Just stick your head in at the waist opening and it functions as a nice little dark hood for focusing. In full sun, I could see light coming through the weave, but for all practical purposes the ground glass was in full darkness. When all is ready, just pull the shirts forward over the bellows and insert the film holder.

I think the only real problem is that the shirts are a little too long. It would work fine with about 6 inches less shirt tail. Maybe next time I'll start with a woman's half shirt.

What is it about Photographers' Formulary TD3 that is better than Technidol, other than price? I did a quick web search for it and found very few references. And the ones I did see are somewaht contradictory. AND the Photographers' Formulary web site only says it is used with Tech Pan and the price it sells for.

Details! I need Details!

Well, I went and did it.

After several weeks of looking and debating, I decided to shoot some

Tech Pan 4x5 sheet film and develop it at home in a tank. I did not

want to use the Kodak recommended tray method, because it seemed to

be way too difficult.

The short answer is, they seem a little thin, but definitely

useable. I have details in the shadows, and the highlights don't

look blown out.

As for technique, this is it. I have a nominal 64 oz. sheet film

tank, that will hold up to 10 hangers. I went out and shot 8 sheets

of film at 25 ASA, using the Sunny 16 rule. Why? Because my meter

died at the last minute, darn it! 3 shots were straight, 3 were shot

with a #25 Red filter and two stops more exposure, 1 was a pretty

girl I happen to know, and 1 was blank (note to self: stop talking

to the girl and write down what you just did). Loaded all the film

into the holders and into the tank, leaving plenty of slosh around

room.

I mixed Technidol liquid developer, 3 packets, into water and diluted

to 60 oz. The reasoning goes like this. The minimum liquid to cover

the film is 55 oz. Kodak says 2 Technidol packets are designed to be

mixed to 16 oz, but can be diluted slightly to 20 oz for use in tanks

such as a Patterson 2 roll. Also, the instruction say that the

developer can be diluted double to 32 oz for sheet film development

in trays as a one shot developer. OK, so I reasoned that if I add

another packet, I can dilute to 48 oz. I can stretch that up to 60

oz, which is what I need to cover the film. but now I'm a bit too

dilute, so I'll add some time. Thus, 60 oz dilute developer, from 3

packets of Technidol liquid, at 68F, for 9 minutes.

OK, here goes. Film is in the tank, I took the room dark, added

water, then closed the tank. I sloshed it around for a minute, then

poured it out. It picked up a brownish color I assume is the anti-

halation layer.

Added developer through the tank light trap. Bounced the tank

against the table top hard several times, then rocked it side to

side, in parallel with the film, 10 times in 10 seconds, every 30

seconds. I used a clothes pin under the tank for a while, to get a

good feel for how much to rock. At 8:45 I poured the developer out

and dumped it. It was clearish.

I added stop bath for 1 minute, rocking side to side twice, then

poured that out. No change in color.

Fix for about 8 minutes, side to side for 10 secs every minute or

so. Then I opend the tank to see if I was wasting my time. Nope,

definitely have images on 7 of 8 sheets. No. 8 was a screw up.

Hypo for 5 minutes, wash for 8, PhotoFlo for 1, then hang to dry.

As I said, they are thin. I suppose I could agitate more, or even go

with 4 packets of developer. But that much developer is expensive,

and it screws up the symmetry of the Technidol packets, which are

sold in 6 packs. One other thing, this package of Technidol was old,

very old, maybe 5 - 8 years, so it might have been weak. The packets

appear very hermetic, but that could be a factor too.

Overall, I think I am pleased. I will have to wait to get contacts

and enlargements made, but it seems this is definitely a slightly

simpler way to process Tech Pan.

OK, I did it! Took off the tab with a Dremel tool. Slow grinding, taking my time to keep the edge flat and not go too far in either direction. I had two problems though.

First, the back is made of aluminum (I think) or some other soft metal, so the grinding tool I used got fouled with some of the metal, making progress slow until I realized the problem. Second, there may be a slight light leak, during focusing only, due to the way the ground glass frame closes over the where the tab used to be. I checked for leaks with the Toyo back, a Graflex back, and sheet film holders, and they are all fine.

At this point, the whole thing is in usable condition, but I really should paint the little strip of bare metal left behind. Now that I know it is aluminum, I'm not as concerned about rust as I was. But appearances are important. Of course, it means masking the whole thing carefully just to give it one shot of spray paint. So it may wait a little while.

bill

OK, here is a picture.

Try not to laugh, I have a very cheap Agfa digital camera, and I'm only just learning to use it. My REAL photos are much better.<div></div>

http://www.ilford.com/html/us_english/prod_html/custommfg/custommfg.html

Looks like Ilford is ready, willing and able to do custom production jobs for the customer ready to pay. Of course, I have no idea what the price might be for a run of 400 Delta (just plain sheets in a box for me, thanks), but it looks like they are ready to discuss it.

This could be a niche market for them, sort of a custom film eBay: we will make one-off production runs of uncommon films once per year, but you must have your order and deposit down by date X, delivery one month later. 400 Delta in Jan, SFX in Apr, PanF in Jul, 3200 Delta in Oct, XP2 every Leap Day ;-)

And the page says they are an independent company, so I guess that means they were sold off.

You have me almost right. The holder will fit under the ground glass if I expand it to its limit. I agree this is probably not the best thing to do though. The second time I tried it, the retention springs slipped off the holder arms. Easy to fix, but a potentially expensive mistake.

I don't mind removing the ground glass at all. The problem is that on the left side is a piece of metal sticking up from the face of the rotating back that prevents the Toyo film holder from sitting flat. Calumet must have had something in mind when they formed that ridge that way, but I can't figure out what. Hopefully, it was not to just prevent me from doing what I'm trying to do.

Bill

I have a Calumet 4x5 with a typical Graflock rotating back. The back

of course accepts sheet film holders, and will open just barely

enough to hold a Toyo 6x9 roll film holder. I like this holder, it

looks like it will keep the film flatter than the equivalent

Calumet. One problem: there is a metal ridge on the side opposite

from where you insert the film holder that prevents the holder from

getting a light tight seal. Looking at the ground glass, with the

holder inserting from the right, this interfering tab would be

sticking straight back towards the photographer. It is part of a

larger ridge that stops the holder from sliding out the other side.

About .25 x .1 inch of tab would have to be removed to get the Toyo

holder to lay flat. From what I can see, taking out that much of the

ridge would not interfere with the operation of sheet film holders,

Polaroid backs, or regular Calumet roll film holders. Am I missing

something? Is there some reason that I need it there that I'm not

thinking of? It could interfere with future resale value, I suppose,

but if that is the only thing, I am willing to risk it.

By the way, the tab also interferes if I remove the ground glass

entirely. The Toyo has slots that will accept the sliding pinch

rails on the Graflock back, but the tab still prevents the back from

lying flat. I'd probably have to take the back off anyway, the Toyo

advance lever does not clear the ground glass frame in normal

operation, so the holder has to come out to advance the film.