Any Current Light Meters down to ASA 1 (or below)?

Andre Noble · Mar 27, 2016

Hello, all light meters that I have ever had have only go down to ASA 3.2 or 3. I use materials with ASA lower than that... Such as efke IR820 and Harman direct positive paper.

I realize I can do the math and get to ASA 1 from an ASA 3.2, but materials at that ASA are so particular, it just makes for another way to miscalculated exposure.

Any new meters out there go down to ASA 1 or lower?

paul ron · Mar 27, 2016

0.8 on the Luna Pro, SBC is the same.

Pentax spot meter... is only 6

MartinCrabtree · Mar 27, 2016

While not modern by any standards my Weston Master II goes down to .3. That would be Weston EI which is about 1/3 stop down from ASA. They are available all over and can be rebuilt to new by George Milton of Quality Light Metric in Hollywood. If all else fails.............

DWThomas · Mar 27, 2016

The Pinhole Assist app for iPhone goes down to 0.25. I installed it a while back but haven't yet actually used it, so can't offer a review. The Pocket Light Meter app goes down to 0.8; that I have used a bit successfully, but won't claim exhaustive testing. There's also Reciprocity+ to deal with compensation for lo-o-ong shutter speeds (just in case you are working up to Worldwide Pinhole Photography Day on April 24th!)

RobC · Mar 27, 2016

http://www.spectracine.com/product_2.html

methinks that what you really need is something which has very good sensitivity in the dark which the above unit does. But you can only set it down to ISO 3 = ASA 3
It reads down to 1 lux

The offset from there to ASA 1 is 1 2/3 stops so all you need to do is increase exposure by 1 2/3 stop to the reading taken at ISO 3

Andre Noble · Mar 27, 2016

Is it really a full 1 and 2/3 stops from ASA 3 down to ASA 1? ASA 3 to 1.5 is 1 stop. Then from ASA 1.5 to ASA 1.0 is 2/3rds of a stop? If correct, that is helpful to know.

Also using Efke IR820 and Harman direct positive paper, my exposures are from 1 second and longer. It's difficult to get 2.5 seconds accurately, for example.

Maris · Mar 27, 2016

My last batch of 8x10 Efke IR820 had lost speed so badly that its EI behind an IR720 filter was just 0.07. So I set 7 on the light-meter and just multiplied the exposure time by 100. If it were as fast as EI = 1 I'd have set 10 and multiplied indicated exposure time by 10. Easy?

RobC · Mar 27, 2016

Andre Noble said:
Is it really a full 1 and 2/3 stops from ASA 3 down to ASA 1? ASA 3 to 1.5 is 1 stop. Then from ASA 1.5 to ASA 1.0 is 2/3rds of a stop? If correct, that is helpful to know.

Also using Efke IR820 and Harman direct positive paper, my exposures are from 1 second and longer. It's difficult to get 2.5 seconds accurately, for example.

There is some rounding becasue half of 3 uses 1.6 when it should really be 1.5 and half of 1.5 is 0.75 but they use 0.8. So infact you can take your pick because it can be 1 2/3 stops or 2 stops Which is actually ASA 0.8. If you want closest to ASA 1 then I'd suggest 1 2/3 stops and see how you go. Assuming you have an ASA lightmeter which is actually accurate at that level of lighting. My suspicion is that it may not be so I would get it carefully checked/calibrated before relying on what it's telling you.
The spectracine meter looks like a nice piece of kit if you have money to burn (they ain't cheap)

Andre Noble · Mar 27, 2016

Maris said:
My last batch of 8x10 Efke IR820 had lost speed so badly...

Man, sounds like extreme degradation of the sensitization dyes. Are you sure you did not switch to an improper filter? Or did your film get chemically fogged?

Andre Noble · Mar 27, 2016

Maris said:
... its EI behind an IR720 filter was just 0.07. So I set 7 on the light-meter and just multiplied the exposure time by 100. If it were as fast as EI = 1 I'd have set 10 and multiplied indicated exposure time by 10. Easy?

That's an excellent idea. I Just tried it. I set ASA 10, got 10.3 seconds, so to get to ASA 1 I divided by 10 and ended up taking picture at 1 second, with a second sheet at 0.5 second. This has been a very informative thread. Thanks

MattKing · Mar 27, 2016

Maris said:
If it were as fast as EI = 1 I'd have set 10 and multiplied indicated exposure time by 10.

Andre Noble said:
That's an excellent idea. I Just tried it. I set ASA 10, got 10.3 seconds, so to get to ASA 1 I divided by 10 and ended up taking picture at 1 second, with a second sheet at 0.5 second. This has been a very informative thread. Thanks

I think you divided when you should have multiplied.

You should have set it to ASA 10, got 10.3 seconds, then multiplied by 10 to end up with 103 seconds.

This of course would then leave you with dealing with reciprocity failure (maybe).

Andre Noble · Mar 27, 2016

My bad. Set my meter ASA 10. It told me to expose at "10.3", meaning 1/10.3 seconds. Multiply by 10 gives me 1.03 second.

It is the sekonic L478dr, so getting used to it.

MattKing · Mar 27, 2016

Andre Noble said:
Multiply by 10 gives me 1.03 second.

Nope .

1/10.3 x 10 = 10/10.3 = 0.97 second

That 6/100 of a second difference may be a game changer!

Maris · Mar 27, 2016

Andre Noble said:
Man, sounds like extreme degradation of the sensitization dyes. Are you sure you did not switch to an improper filter? Or did your film get chemically fogged?

Extreme degradation of IR sensitising dyes is what happened. Exposing bad Efke IR820 film + IR720 filter at EI = 0.07 is not really that hard with a tripod mounted 8x10 camera. Here's an example that required 3 minutes at f22:

Snow Gum Path, Infrared
Gelatin-silver photograph on Ultrafine Silver Eagle VC FB photographic paper, image size 19.5cm X 24.5cm, from
a 8x10 Efke IR820 negative exposed in a Tachihara 810HD triple extension field view camera fitted with a
Nikkor-W 210mm f5.6 lens and IR720 filter.

Andre Noble · Mar 27, 2016

That's a beautiful photo. From the grass, looks like it was shot at high altitude. After schlepping 8x10 gear, waiting 3 minutes to properly expose that negative is reasonable.

ced · Mar 28, 2016

There are many exposure discs (look like a round slide rule) that you can print at home & put together like this one.
http://www.ilfordphoto.com/webfiles/2011106152612113.pdf

Old-N-Feeble · Mar 28, 2016

RobC said:
http://www.spectracine.com/product_2.html

methinks that what you really need is something which has very good sensitivity in the dark which the above unit does. But you can only set it down to ISO 3 = ASA 3
It reads down to 1 lux

The offset from there to ASA 1 is 1 2/3 stops so all you need to do is increase exposure by 1 2/3 stop to the reading taken at ISO 3

I would rather set to ISO 4 and add 2 stops because it's easier for my weak mind to calculate.

RobC · Mar 28, 2016

Good thinking which is OK if your meter allows it. Mine only goes down to ISO 12.

mooseontheloose · Mar 28, 2016

Maris said:
Extreme degradation of IR sensitising dyes is what happened. Exposing bad Efke IR820 film + IR720 filter at EI = 0.07 is not really that hard with a tripod mounted 8x10 camera. Here's an example that required 3 minutes at f22:

Snow Gum Path, Infrared
Gelatin-silver photograph on Ultrafine Silver Eagle VC FB photographic paper, image size 19.5cm X 24.5cm, from
a 8x10 Efke IR820 negative exposed in a Tachihara 810HD triple extension field view camera fitted with a
Nikkor-W 210mm f5.6 lens and IR720 filter.

What a gorgeous shot Maris!

Old-N-Feeble · Mar 28, 2016

RobC said:
Good thinking which is OK if your meter allows it. Mine only goes down to ISO 12.

Set to 16 and add 4 stops.

RobC · Mar 28, 2016

Old-N-Feeble said:
Set to 16 and add 4 stops.

If I ever use any of that film I must remember to do that.

Any Current Light Meters down to ASA 1 (or below)?

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Any Current Light Meters down to ASA 1 (or below)?

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