eric_pederson

Of course the real secret is to take exposures which aren't worth printing, since the cost of paper will rapidly exceed the relatively trivial film costs.... :-)

I have thin sheets of overhead transparency film cut to slightly larger than a 4x5 negative. When loading the BTZS tubes, I just put the neg on this film and put both in the tube. When I reach in to catch the photographic film, I mostly handle the transparency film. This is reusable if you wash it. Be sure to put the correct one in the fixer though! :-)

It's the only IR film in 4x5. Fortunately it is also a nice film to work with. Be careful processing as the emulsion is easily scratched compared to other modern sheet films I have used. Lovely clear base material.

 

Like any IR film it is wise to bracket your exposures which obviously uses more film than with roll film. Still I have printed horrifically under- and over-exposed film with success.

 

Keep in mind that diffraction effects are greater at the longer wavelengths, so even if the grain is not so bad (becoming visible at 4x in my opinion), the diffraction may become quite obvious at larger enlargements. For me at 3x and over when stopped down to f32. This gives a soft effect which may be quite suitable for some prints.

 

You might consult my webpage on the film:

http://darkwing.uoregon.edu/~epederso/Photo/IR/Test.html

though I don't specifically deal with the sheet film version of it there, the emulsion appears to be the same in all formats.

I made homemade tubes which hold 60-65ml of developer. The film holding portion is about 4 cm too long (sometimes I accidently push the film further in and have difficulty extracting it, so that reduces the volume to area ratio more than it should if you make the tubes correctly shorter. That said, I have found that it is difficult to get the full range of development (to N+2) with Tmax100 and Xtol 1:1, so all my formulae are with Xtol full strength (which is fine and faster).

 

For what it's worth here are my times with (old) TMX at full strength Xtol and constant agitation @20C. No times for the new TMX:

N-2 5 min EI 50 /

N-1 6 min EI 64 /

N 7.5min EI 100 /

N+1 9 min EI 125 /

N+2 10.5 min EI 160

I understand Maco is releasing their 820c B/W Infrared film in a "halo" version, i.e. without the antihalation backing. This is a 100 ISO film with very extended red sensitivity, but you would get fairly normal B/W images if you don't use anything darker than a yellow filter. Grainier than most normal 100 ASA films and a very delicate emulsion so you need processing care -- although scratches in the emulsion may contribute to that "old" look to the image... :-)

I meant to provide that photo as a link, not as a photo imposed on the forum's readers. My apologies! (Can I delete?)

If you don't want to do your own testing, add 30-40% more dev time to the stock recommendations for EI 3200 and higher. I develop TMZ/P3200 with EI6400 in full strength Xtol to my satisfaction. You are pushing the limits of the film and probably using a fast shutter speed which may not be consistent in your camera. You may also be photographing in high contrast lighting situations (as is typical in low lit environments). I suspect that Kodak gives lower dev times than I like for the heavily pushed film because they know you will be unhappy with excessive contrast ( I largely agree with the slower EI recommendations). Well, we know you you are unhappy with thin negatives (and can happily print at grade 0?), so give them a longer soak in the dev, and try agitating only once per minute. If that doesn't work for you, the other posters are correct: you like to use film properly, not pushed several stops!<div></div>

I'll second the call for not pushing film anymore than necessary. No one is going to care about the grain, but they will be very unhappy if the contrast on their face is too high! Use the fastest film you can use and be happy if you can pull it. Fast glass is great for focussing, but stop down as much as you can for the actual exposure. Assuming these are going into 8x10 or greater enlargements, you'll find you want quite a bit of d.o.f. for most shots. Consider a conversation between two actors and one is a meter further upstage from you. You may well want both in sharp focus.

Just to add to sheet film times (also determined with a step tablet):

4x5" in BTZS tubes with 65ml/sheet full strength Xtol at 20C:

 

N-1 3.5 min EI 200

 

N 7.5 min EI 400

 

N+1 12 min EI 640

 

N+2 20+ min EI 800

 

These are fairly consistent with Glover's higher temp / lower concentration results. Xtol seems to give about 1/2 stop greater speed than most other dev's with HP5+.

I don't use HP5+ roll film, so I can't offer any direct comparisons.

Don't forget that you have already added some additional contrast through the reciprocity correction. N dev is probably more like N+1 in contrast results, etc.

Also, you seem to be assuming that the contrast should be high enough to allow the full contrast range of the paper which may or may not be appropriate given the low contrast scene and what you want to do with it.

As stated, if you really want an N=3/4/5 neg, you should go back to the arch and reexpose at a higher EI number or even higher contrast film. If that's not possible, then I would recommend N+2/3 dev and then let printing take care of the rest. (I treat N+2 as the upper limit for HP5+ with EI 800 and Xtol, though I haven't experience trying to go higher in contrast). Since the scene is so low in contrast, you probably don't have that much in the shadows to lose with a high EI....

While you need not use a step wedge and densitometer to do what you are trying to do, why not use them if you have them? Like you I used both following the BTZS approach. I was not impressed with his method of calculating film speed though. So consider starting with that base exposure to expose sheets for contrast testing and don't worry about speed. Since only about 1/2 of the steps will be out of shoulder and toe, you actually have considerable exposure latitude. Once you have figured out what N dev is, etc., then you can make some exposures assuming various EI and develop them at N and pick the one that best shows the film speed. Then the curves for other contrast gradients will allow you to extrapolate for the other EI vaules. This adds one step in the procedure, but probably gives better accuracy with your most normal shutter/lens flare/ etc.

Under 2/3 stop precision is the probably the best you can hope for anyway given all the variables you can't control.

 

Yes, the taped bit on the negative is for B+H, but for most exposures, you will have trouble distinguishing it from the darkest steps that were on the wedge, so I doubt that it really matters...

Put the film in the freezer and don't worry... I haven't run tests, but routinely develop film months after (I like to do it in batches). Just be sure everything has warmed up before you open it to develop...

To add to what David Beal said about homemade ABS tubes:

 

"Before each use, put a short length of Teflon ® tape on the threads of the male adapters and the threads of the plugs. After each use, remove & discard the piece of tape"

 

I added a semi-permanent O-ring at the base of the male threads. (The threads on the pieces from my hardware store seem molded to accomodate this.) Never a leak and no need to use tape.

I recently acquired a 1970's Vivitar 600mm f/8 telephoto lens with

no lens cap. I'm having no luck finding the correct size food

container lid! Anyway, it appears to have 90mm threading with 93mm

push-on size. Any recommendations of best after market source for

caps -- my usual sources seem to lack this size (though B&H lists a

generic 92mm push-on which may well work). My local camera shop

sells a neoprene slip on lens bootie which should afford some

protection, but seems a bit loose and would only cushion not stop

impact from striking the glass.

 

This beast would obviously benefit from a hood too and I'm wondering

if I'm stuck with masking tape and black construction paper!

I have a page on the film as well. With Xtol dev, I usually rate at EI 10 (ASA not DIN) for 35mm film, EI 8 for sheet film, EI 3 with strobe, all with Hoya R72 filter. It's very difficult to really estimate an EI unless you directly meter just the IR light. Bright sun is faster, shadow is very slow.

Anyway, the web page links to some basic images to get a sense of contrast, etc....

http://darkwing.uoregon.edu/~epederso/Photo/IR/Test.html<div></div>

It's worked well for me. I think that if the cartridge had the power to damage the film you wouldn't want to be handling it very long....

Thanks for all the replies.

 

Chris (and following): f32 sure seems dim to me (unless I'm in sunlight or other bright conditions) as I frequently am in deep shade, early morning, or rustic interiors. I admit that I usually let some light under the darkcloth for air. I've also been using reading glasses instead of a dark tube lupe.

 

I'll look up the book -- I've seen the webpage which discusses d.o.f. and I can somewhat extrapolate to use outside dof, but perhaps the book will address this more carefully. I find it interesting how much information and discussion there is on "sharp" and how little there is on "blurry" as though one and not the other were important to a photograph!

All this recent discussion about where the apparent d.o.f. lies and

how to get everything sharp encourages me to ask:

 

Does anyone have good tips for how to estimate the degree of blur in

out-of-focus areas? As an example, I could use f16 or smaller

aperture to have everything I want in apparent focus to be

adequately sharp. I want a blurred background, but with some detail

recognizable. For example, perhaps I would like a background face

identifiable as a face, but not recognizable as a specific face; or

I might want individual leaves on distant trees discernable, but

sufficiently unsharp as to be undistracting to the main subject; etc.

 

I can accurately estimate the d.o.f., the distance to the plane of

focus, and the distance from the plane of focus to the blurred

background. Now what?

 

Obviously checking the apparent sharpness at f32 is going to be a

bit dim under the darkcloth, so that is a poor option. I don't know

how to go from calculating a large c.o.c. value to the degree of non-

focus in the final print. Plus, that would be potentially cumbersome

math to do in the field (I let software do the work to determine the

d.o.f. range). Bracketing is often a poor option.

 

What would be nice is a way to estimate the increase of sharpness as

I stop down one/two/three/etc. stops from the amount of blur of the

lens wide open. I have a rather vague intuition for doing this but

it isn't very reliable. It seems that another tool might be to

measure the amount of change in bellows extension necessary to bring

the desired blurry area into focus as a way to make a more precise

estimate of how sharp this will be when stopped down.

Of course, any mathematical values would still need to be converted

to the subjective impression of blurry resolution in the final print

and I'm hoping some others good verbalize techniques which have

worked well for them.

 

Any tips to share?

I've just switched from 16x20 to 20x24 inch as my most typical target printsize. Each time I go up a size, I find that the apparent d.o.f. shrinks, which is the primary limiting factor for many images. Grain isn't relevant (hey it's a photograph!) and except for infrared negatives, reduction of resolution from diffraction seems unimportant compared to what is gained by more enlargement. Apparent d.o.f. is important to me, because the main visual interest is typically within that d.o.f. and for that the viewer will reduce viewing distance to inspect. I now wish I could magically stop down some of my favorite negatives... :-(

Here's a follow-up:

I finally made some test sheets with the following results

for 4x5 HP5+ 60ml Xtol full strength BTZS tube @20.5C

 

N-1 3.5 min EI 200

 

N 7.5 min EI 400

 

N+1 12 min EI 640

 

N+2 20+ min EI 800 (I'm extrapolating this data point as my longest dev time was 16 min)

 

This is 1/3 stop faster than TMY for N dev, but 2/3 faster for N+1.

It also suggests that I could marginally use HP5+ with Xtol at EI800 and still have a printable negative in non-harsh lighting which would

be impossible with TMY. This is not a dramatically faster film for my conditions, but an extra 2/3 stop might help from time to time...

For high contrast scenes, I'm better off with another film as developing time is frighteningly short.

 

Thanks again for all the input!

Ditto for my also using the Nikkor 300 on a Tachihara (with rated 330mm extension). I would love another cm of extension, but the front of the camera is not that stable. And ditto on the avoiding heavy lenses out there. If 4m is an acceptable minimum focus distance, you're fine. Keeping a simple flat lens board is much simpler/cheaper/more stable/compact, etc.

 

Focus can come down to about 3.4 meters with various movements. Still too short for portrait work, but fine for the landscapes and such that field cameras are typically used for. You already have a 240mm lens though which is perfect for portrait distance. I can't imagine you would be tromping in a swamp with both a 240 and 300 mm lens though as they are nearly redundant. Be sure that the extra distance is worth it to you. The advantage of a telephoto is that you could get up to 360+mm on the lens which would be a genuine step longer than your current 240mm lens. On the other hand, if you can afford some of the new tele lenses, you could probably afford a camera with more bellows too!

The brighteners will wash out (which may be just as well since they might fade or discolor in years of display anyway) and if soaked long enough the emulsion will loosen. Why don't you just take them out of the water and let them dry overnight. The next morning, just reimmerse them and continue washing. If they are fixer-laden in the evening, then you would want to store them somewhere other than your normal drying racks so they don't contaminate them and this might cause a storage problem.

Or make your own BTZS-style tubes. There's a guide to making them in the BTZS book, so obviously that is encouraged. That said, they won't be as good as the manufactured ones (which come with a great tray). I've made my own with some modification to that design (you can contact off-list for details), though I confess that the materials cost for 6 tubes and 12 caps came to about $65-$70 (US Dollars), so with labor, you might be as well off buying the official set (new or used). Developing chemistry is pretty cheap compared to, e.g., paper to print on, so I'm not sure that's the best place to worry about expense. Oh yes, development has been pretty darn even for me.

I've been fairly pleased with the Maco 820c IR film in 4x5 (which is

the main format I use the film in). Try it and see. Not only less of

a halo than the Kodak offering, but less severe IR effects -- at

least with the IR72 filter. I have a web page on the film with exx

from 35mm format at

http://darkwing.uoregon.edu/~epederso/Photo/IR/Test.html

I'll be updating that page next month after I finish some tests with

IR filtered strobe light.

It's the only game in town for 4x5 IR work, so if you are interested

in such, then you need to find a way to make the film work for you!

Also consider pulling the Provia. Fuji recommends pulling by a full

stop (EI50) and I have seen no color shift in doing this. You might

try pulling by more than a stop and see if you can gain even greater

latitude. You will probably get some color shift, but if you are

scanning anyway...

 

<p>

 

There would be a certain advantage to reducing the number of films

you carry, and if you are pleased with Provia 100F, you should see

if you can make it meet your purposes. My estimate is that it can be

pulled to have as much latitude as normally processed negative film.

Of course, it will never match pulled negative film in capturing a

very long contrast range, so if you are photographing serious dark

and light (e.g. sunlit church interiors), you probably have little

choice except to use negative film. If you are scanning the

negative, I would expect that the scanning settings would have more

to do with approximating the Provia than which film you are

scanning, but I'm emphatically not an expert here.