Light meter for pinholes

[Ces1um]

Does anybody know if someone manufacturers a light meter that provides aperture ranges more suitable for pinhole cameras? I understand most stop at around f90-ish. I'm surprised sekonic doesn't offer something (or a software upgrade, etc...) that allows for very small apertures. So far I've been unsuccessful finding anything. I know there are calculators/wheels out there for conversion but I was hoping to find something a little more direct.

 

[MattKing]

I have tables printed on to cards that have columns for the recommended exposure for f/22, the resulting exposure for my pinole (f/207) and the necessary in field exposure (to take into account reciprocity failure). The tables were generated in a pinhole related Windows program.

 

[Ces1um]

I have tables printed on to cards that have columns for the recommended exposure for f/22, the resulting exposure for my pinole (f/207) and the necessary in field exposure (to take into account reciprocity failure). The tables were generated in a pinhole related Windows program.

Like I was saying though, I was hoping for a proper meter rather than resorting to a calculator/wheel. I just noted a post though from another member about an app that goes all the way up to f512 so that may end up being what I resort to unless I can find a meter.

 

[removedacct1]

I cannot recommend this more highly: https://itunes.apple.com/us/app/pinhole-assist/id466757473?mt=8

 

[chdorner]

I cannot recommend this more highly: https://itunes.apple.com/us/app/pinhole-assist/id466757473?mt=8

I don’t know why but I always liked Pinhole Master better, I think the reciprocity failure data is better, but I might be wrong. And the interface to add your own reciprocity failure curves is much nicer, although the last time I’ve used hat is quite a while ago.

 

[Ces1um]

I cannot recommend this more highly: https://itunes.apple.com/us/app/pinhole-assist/id466757473?mt=8

Do you think it would benefit from the "lumi" lumisphere add on? I have to say, that app looks amazing from the screenshots on the website.

 

[darkroommike]

My LunaPro F and Luna Lux SBC both go to f/128, from f/128 to f/300 is EV -2.5 (one and 1/2 stops), easily calculated, and then "punt"
due to reciprocity,.

 

[GRHazelton]

Hmmmm..... I wonder if my Pentax LX, TTL off the film metering to ... hours ... might automate the process. I might have to sacrifice a body cap!

 

[removedacct1]

Do you think it would benefit from the "lumi" lumisphere add on? I have to say, that app looks amazing from the screenshots on the website.

I've been using the Pinhole Assist app since 2012 and have never found it lacking in any way. I've never felt a need to purchase the Lumi add-on - the onboard camera does an excellent job as is.

 

[Ces1um]

This email is a natural hand-made product. The slight variations in spelling and grammar enhance its individual character and in no way are to be considered flaws.

Hehehe. Your signature line is pretty funny!

 

[Ces1um]

I've been using the Pinhole Assist app since 2012 and have never found it lacking in any way. I've never felt a need to purchase the Lumi add-on - the onboard camera does an excellent job as is.

That's great to hear! I've been mulling over getting a pinhole camera for a while now but being new to it I didn't want to add additional complexity to my first experience with it. I'll download that app and give 'er a try. Now to just finally decide on which pinhole camera....

 

[Barry Kirsten]

I just take a light reading for f/16 then count down 8, 10 or 12 stops, depending on the pinhole I am using to get the right exposure. For exposures over about 4 seconds I add a little more exposure for reciprocity effect. Or I just estimate exposure based on experience with that pinhole and the light at the time. If in doubt that I have the right exposure I add a bit more. Sounds a laughably rough way to work, but I've found pinhole really forgiving and always seem to get good exposures. I'm not trying to sound a smart ass, binhole is a wonderfully simple and intuitive process and I like to work on my technique to keep it that way.

 

[Chan Tran]

The calculation is easy. In fact you only need from the meter the light level of the subject and nothing else. If you want a meter that does the calculation for you then I don't think there is any that would go to 256 etc.. The reason? There is no real need for it.

 

[Luckless]

Phone apps seem like the fastest/easiest solution to such a problem. But some other options off the top of my head...

If you are typically using a single film and have a meter that gives you an EV reading which you then manually set the exposure dial with, then it wouldn't be terribly difficult to relabel the dials with precalculated values suitable to the camera setup you're using. It gets even easier if you're working with a truly fixed aperture value for your pinhole work.

With something like a Gossen Digiflash or Digisix (A light meter I happen to own) for fixed aperture, I would set my pinhole's f/value as the centre point in the F stop scale, and calculate out the shutter speeds for each corresponding EV on the scale with suitable compensation values, and then carefully remark the shutter speed scale on the dial.

Of course, if you wanted to get really fancy with such a modification, the obvious solution would be to flip the meter over and modify the lower housing. Add a secondary dial scale for your pinhole, while leaving the normal in place. You would then just be flipping it over to transfer the EV to the other scale while still having a unit that fits nicely into a pocket. Could get even extra fancy for the added scale, by building the housing such that you could quickly open it to flip your scale ring for different pre-computed values, or even have a whole stack of marked scale rings ready to use.


Beyond something like that, I expect you would be looking at a decently complex Arduino project or something to get that heavily customized of a light meter.

 

[removedacct1]

That's great to hear! I've been mulling over getting a pinhole camera for a while now but being new to it I didn't want to add additional complexity to my first experience with it. I'll download that app and give 'er a try. Now to just finally decide on which pinhole camera....

The first thing to decide is: do you want to work with sheet film or just roll film? Or both?

 

[GRHazelton]

Hehehe. Your signature line is pretty funny!

Thank you! Thank you very much!

 

[MattKing]

Like I was saying though, I was hoping for a proper meter rather than resorting to a calculator/wheel. I just noted a post though from another member about an app that goes all the way up to f512 so that may end up being what I resort to unless I can find a meter.

It isn't a calculator or wheel. It is just a little card, and is specific to one film and one pinhole.
I take a reading for f/22 - my meter gives me a time.
I read that time on the table, it gives me another time to actually use.
Here is the card, as supplied by the pinhole "manufacturer (it is for FP4):

 

[NedL]

Matt, that last row is particularly useful.
My calotypes are about ISO 0.006. It tells me my exposure should be 6129.04 years. I'd better start soon.
( If we use a regular commercial photopaper negative, we can cut this down to a quick 6 years! )

 

[DWThomas]

Matt, that last row is particularly useful.
My calotypes are about ISO 0.006. It tells me my exposure should be 6129.04 years. I'd better start soon.
( If we use a regular commercial photopaper negative, we can cut this down to a quick 6 years! )

I've often suggested a folding chair as part of one's pinhole kit.

For quite a few years now as a user of Pinhole Designer, I have taken advantage of its ability to crank out an exposure compensation table for a specific film in spreadsheet format. It can also optionally include reciprocity adjustment, although it only covers a limited selection of currently available films. The program is old and has not been updated for at least a dozen years, so some newer films are not included. And the aforementioned spreadsheet is an early Excel format, but (so far) Excel complains but opens it. It would be nice if the program could be updated for newer films and maybe even a user configurable reciprocity setup. Unfortunately the original programmer has apparently moved on to other things.

The Pinhole designer approach comes up with a multiplier based on using a regular meter reading at f/22 and applying the multiplier to the shutter speed. Given pinhole tends to be a slow process, taking a quick look at a pocket sized card to adjust the exposure seems easy enough. I have also experimentally come up with numbers for other material -- such as X-ray film.

I have more recently dabbled with a couple of the iPhone apps. I also view pinhole as an inherently inexact process and try not to obsess over fractional stop precision. Often a consistent, repeatable procedure is more important than absolute accuracy anyway.

That's my 1.3 (after tax) cents.

 

[Ces1um]

I've often suggested a folding chair as part of one's pinhole kit.

such as X-ray film.

.

I happen to have access to both xray film(8x12) and an x-ray film processor/developer (which I use to develop my black and white film). They don't post any iso information on the film box but does say to use safelight 8u. I always wondered what it's iso might be. Very expensive to just try and figure out with no starting point though which is why I never gave it a try.

 

[tezzasmall]

Hmmmm..... I wonder if my Pentax LX, TTL off the film metering to ... hours ... might automate the process. I might have to sacrifice a body cap!

I bought a body cap with a lasered pinhole shim and all of my Pentax 35mm cameras gave spot on automatic exposures using the built in metering, and I found that I bracketed unnecessarily.

Terry S

 

[tezzasmall]

It isn't a calculator or wheel. It is just a little card, and is specific to one film and one pinhole.
I take a reading for f/22 - my meter gives me a time.
Here is the card, as supplied by the pinhole "manufacturer (it is for FP4):
View attachment 188146

Wow! Those exposures on the card from 2 seconds upwards can't be right surely? I've used FP4 in a 35mm TTL Pentax with a lasered pinhole and the exposures were always in the ball park of a few seconds...?...

Terry S

 

[DWThomas]

I happen to have access to both xray film(8x12) and an x-ray film processor/developer (which I use to develop my black and white film). They don't post any iso information on the film box but does say to use safelight 8u. I always wondered what it's iso might be. Very expensive to just try and figure out with no starting point though which is why I never gave it a try.

Yeah, they don't commit to regular photography! I have been using 8x10 Fuji HR-T in a camera I built. If you search these forums you are likely to find recommendations from about ISO 50 to ISO 400 for that. I find the lower end does better for me. The stuff (and probably others) tends toward very high contrast, so taming that can be a challenge. I've been shooting it around ISO 50 and developing in HC110 1+63 ("Dilution H") on my last couple go-rounds. I used developing times down in the 3 to 4 minute range, even at that dilution; the X-ray stuff comes up fast, almost like paper prints. The double-sided emulsion adds another hazard, but I have found developing in Cesco smooth bottom trays works well. The Fuji stuff is green sensitive and wants a dark red (Kodak #2) safelight -- even red LED bulbs have not worked for me.

Some Worldwide Pinhole Photography Day that finds me with surplus cash, mayhaps I'll buy some "real film" and try it. But I've noted a conspiracy: sellers of film that costs less per sheet tend to package it in larger packages, so no matter what, one has to lay out an alarming amount of money to get started. The aforementioned Fuji X-ray stuff was about $43US shipped for 100 sheets when I bought it and something like 25 sheets of FP-4 is currently $110 at B&H. You can get fifty sheets of some lesser brands for $130 to $160 or so (or pay $104 for TEN sheets of TMY!)

 

[Ces1um]

Yeah, they don't commit to regular photography! I have been using 8x10 Fuji HR-T in a camera I built. If you search these forums you are likely to find recommendations from about ISO 50 to ISO 400 for that. I find the lower end does better for me. The stuff (and probably others) tends toward very high contrast, so taming that can be a challenge. I've been shooting it around ISO 50 and developing in HC110 1+63 ("Dilution H") on my last couple go-rounds. I used developing times down in the 3 to 4 minute range, even at that dilution; the X-ray stuff comes up fast, almost like paper prints. The double-sided emulsion adds another hazard, but I have found developing in Cesco smooth bottom trays works well. The Fuji stuff is green sensitive and wants a dark red (Kodak #2) safelight -- even red LED bulbs have not worked for me.

Some Worldwide Pinhole Photography Day that finds me with surplus cash, mayhaps I'll buy some "real film" and try it. But I've noted a conspiracy: sellers of film that costs less per sheet tend to package it in larger packages, so no matter what, one has to lay out an alarming amount of money to get started. The aforementioned Fuji X-ray stuff was about $43US shipped for 100 sheets when I bought it and something like 25 sheets of FP-4 is currently $110 at B&H. You can get fifty sheets of some lesser brands for $130 to $160 or so (or pay $104 for TEN sheets of TMY!)

So how does the double sided emulsion affect your photos? Just curious. Is it more difficult to print/enlarge, or to scan? Or are you worried more about scratching the emulsion? I'm just wondering because when these films are used for their intended purpose and developed as designed the emulsion itself is quite difficult to damage. I've been thinking about using it cut down in a pinhole camera and then processing it at work. one 8x12 sheet should get me four 4x5 photos (coincidentally filling two toyo film holders just perfectly).

 

[DWThomas]

Wow! Those exposures on the card from 2 seconds upwards can't be right surely? I've used FP4 in a 35mm TTL Pentax with a lasered pinhole and the exposures were always in the ball park of a few seconds...?...

Terry S

I don't know what film those were for, in general the table looks suspiciously like the output from the Pinhole Designer utility I mentioned upthread. In that case, the built-in adjustments could be suspect as outdated. One of my early pinhole outings used a 120 roll of Delta 100 and I was left with the impression that the published reciprocity data was maybe a little excessive. There were too many variables in the overall project to point fingers at one parameter, but I believe just recently Ilford has released some updates on their reciprocity info. For the tables I've carried in the field I have generally chopped them off beyond an hour of adjusted exposure. (It's too hard to carry a folding chair along with all the other stuff. )