18% Grey Card. To use it or not.

[BrianShaw]

It should be added that, for correct readings with spotmeters, they should be shaded just like camera lenses to prevent flare. Better ones, like the Pentax, have multicoated optics. But that is not enough by itself if facing the sun or bright reflections. Mine also carry collapsible rubber lens hoods.

Excellent point about lens hood!

 

[wiltw]

It should be added that, for correct readings with spotmeters, they should be shaded just like camera lenses to prevent flare. Better ones, like the Pentax, have multicoated optics. But that is not enough by itself if facing the sun or bright reflections. Mine also carry collapsible rubber lens hoods.

The advantage of spot meters in relation to high contrast snow scenes etc is that you can compare distinct high value and low value readings and strategize from there, based on the dynamic range of your chosen film. For example, there are numerous times I've had to deal with bringing out the brilliant specular sparkle of ice or snow, which still needing to bag the distinction between black volcanic rock and little black dark pits and cracks in it. In open sun, especially at high altitude, that can easily become a 12-stop problem, and not just any black and white film can handle it. But even with the longest scale ones, you still have to give careful "placement" of key values.

And with color film, especially chrome, something is going to have to be sacrificed - either the shadows or the highlights. Or else, just move along, and look for a more suitable shot. This amounts to much of my life outdoors. It's ludicrous to defer to fill flash or imagined film "latitude" under such circumstances, especially if the anticipated outcome is an equally rich and nuanced print. Exposure needs to be on target in a manner mere averaging is incapable of.

Thx for pointing out a very valueable contribution of the spotmeter...measurement of the full dynamic range of the scene, to permit one to 'place' the exposure to best capture that scene, allowing one to choose what part of the range to sacrifice (when the dynamic range exceeds the film capabilities) or to adjust illumination with supplmental lighting (or reflectors). I alluded to that DR use in my description of measuring the DR of my wine bottle + filled wine glass photo (post 64) and the need to limit to 7EV of DR. I have measured scenes with 13EV of DR when out shooting in the field!

 

[MattKing]

US doctors won't email prescriptions or reports, require fax machines or you have to use the doctor's or hospital's medical portal. This might have to do with the Federal privacy acts and that email is not considered secure. Although if the fax is using VOIP, it's going through the internet anyway, isn't it?

Same here, although our doctor has a fax card in the clinic's network that is used to digitally create the prescription document directly into fax transmittable form - no paper created.
The challenge was probably getting the rules to accept digital signatures.
There may be some encryption involved, meaning that only designated and pre-set up pharmacies and other designated destinations can decode the fax.

 

[Taylor Nankervis]

It should be added that, for correct readings with spotmeters, they should be shaded just like camera lenses to prevent flare. Better ones, like the Pentax, have multicoated optics. But that is not enough by itself if facing the sun or bright reflections. Mine also carry collapsible rubber lens hoods.

That discovery dawned on me like a brick on the head about 17 years ago, with the first Sekonic L758D. Without a rigid, screw-in hood on the front, it was prone to flare and botched readings; the flare was often outside the viewfinder frame and not readily apparent when sweeping a scene at speed, as I learnt to do very early on. Enter, a nicely machined Rollei metal and flock-lined hood, and buggered exposures time are but an aberration sinking into antiquity.

I would not ever use any spot meter now without a hood on that very vulnerable front lens. Of course, a hood protects the lens there from the everyday knocks against tripods, rocks, trees and anything else it swings toward.

 

[Taylor Nankervis]

And with color film, especially chrome, something is going to have to be sacrificed - either the shadows or the highlights. Or else, just move along, and look for a more suitable shot.

I don't want anything sacrificed when I have control of when, how and why I shoot.
I am patient enough to take notes of what the scene presented to me if the lighting is not right, and plan to return when the lighting is right. To that end, I enjoy, very much, shooting in diffuse/overcast/flat light (even rain is pleasant) — I leave the crappy shots in bright light to playing with my vintage Olympus XA loaded with Provia 100F. It is not impossible to photograph a high contrast scene and lose either highlights or shadows,. but it requires a lot of judgement, care and experience, and even when all the crumbs of the cookie line up, sh!t happens. Duplex metering of several areas of highlights and shadows and then balancing against a grey card has worked for me many times. Next April I will be on an artist-in-resident in western Tasmania, in the famed Takanya/Tarkine Rainforest, SW of Waratah, shooting-to-exhibit (with a group). I expect in April to get days of bright sunshine that will pose a challenge, days more of rain and cold, and a couple of days when everything works out just so! I'm probably the fastest and most fluent with a multispot meter over my other large format comrades using incident meters (shudder).

This scene below is one that on two occasions in high summer was bathed in the hot white glare of the sun bursting through the forest crown. The creek behind was barely running, so no problem with spectrals, but there were deep, dark shadows and rapidly changing light. Amazing what happens when you come back in winter and are presented with an entirely more favourable subject and a resultant exposure!

 

[Alan Edward Klein]

Same here, although our doctor has a fax card in the clinic's network that is used to digitally create the prescription document directly into fax transmittable form - no paper created.
The challenge was probably getting the rules to accept digital signatures.
There may be some encryption involved, meaning that only designated and pre-set up pharmacies and other designated destinations can decode the fax.

Except they will send a fax of private reports to my machine at home on VOIP that isn't encrypted. The whole US Federal medical privacy law has made communications more unnecessarily difficult with doctors and medical facilities in America. Most people no longer have or use fax machines.

 

[jvo]

Frame it and hang on display in your Darkroom.

+++++
it won't be long when archeologists will dig one up and wonder "what's this for?" - resulting in a multi-million dollar research project!

 

[Tom Taylor]

I keep one of these in my pack. It's pretty accurate.

 

[MattKing]

Except they will send a fax of private reports to my machine at home on VOIP that isn't encrypted. The whole US Federal medical privacy law has made communications more unnecessarily difficult with doctors and medical facilities in America. Most people no longer have or use fax machines.

Many have fax cards though. And the most important security tool is to make sure that the destination telephone number is where the fax is intended to go.
Of course, if someone is monitoring your calls Alan, all bets are off!

 

[wiltw]

I keep one of these in my pack. It's pretty accurate.

Just wondering what it suggests for exposure with ISO 400 film, when in the inside of a high school gym...spot checking it for suitability.

 

[BrianShaw]

F/2 at 1/60

 

[Chan Tran]

F/2 at 1/60

May be a stop brighter than that but it would be a good value.

 

[BrianShaw]

May be a stop brighter than that but it would be a good value.

Kodak Master/Professional Photoguide suggest between f/1.4 and f/2 at 1/60.

 

[wiltw]

Kodak Master/Professional Photoguide suggest between f/1.4 and f/2 at 1/60.

...still waiting to hear what @TomTaylor's product suggests

 

[BrianShaw]

...still waiting to hear what @TomTaylor's product suggests

Post #111 is what BlackCat recommends.

Having photographed youth basketball, though, there are wide variations in gyms and gym lighting. Most often I’d use flash until asked to stop.

 

[Stephen Benskin]

It matters not if Ansel was right in his assumptions about selected values, just as it really does not matter which K value was chosen by the given meter manufacturer...
the range of K values permitted within the ISO standard only effects the end reading by 'as much as' 1/6 EV !

I should have been more clear. What I was referring to was Adams mistakenly thinking the K factor was an adjustment to exposure. It's not. It's an internal calibration of the exposure meter to adjust for among other things:

R = Luminance distribution factor
p = ratio of spectra distribution between scene Luminance and sensitometric Illuminance
r = photocell's spectral response

Example:

 

[wiltw]

Post #111 is what BlackCat recommends.

Having photographed youth basketball, though, there are wide variations in gyms and gym lighting. Most often I’d use flash until asked to stop.

I simply want to hear what that product's assessement is! I know gyms vary, and I know what I had to use to shoot in those conditions without flash. Other things than basketball games take place in gyms, and I had to often shoot in them for such things, where flash was not necessarily something I could use. Is Brina's reply his own reply, or what that product suggests?

 

[wiltw]

I should have been more clear. What I was referring to was Adams mistakenly thinking the K factor was an adjustment to exposure. It's not. It's an internal calibration of the exposure meter to adjust for among other things:

R = Luminance distribution factor
p = ratio of spectra distribution between scene Luminance and sensitometric Illuminance
r = photocell's spectral response

Example:
View attachment 408620

Interesting, especiallly in view of the fact that different K values are used by different meter manufacturers of modern non-selenium and -CdS sensored meters.

 

[Stephen Benskin]

Interesting, especiallly in view of the fact that different K values are used by different meter manufacturers of modern non-selenium and -CdS sensored meters.

Well, it was only an example of how the spectral sensitivity of the photocell can affect the value of K and evidence how K is a meter calibration constant and not an exposure adjustment. It wasn't intended to be a comprehensive review of all meters. In The Negative, Adams makes K sound like a conspiracy by the manufacturers.

My Pentax Digital Spot Meter has a silicon photodiode, as does the Minolta III according to their respective datasheets. Both have a K of 14. Interestingly, the Pentax datasheet has the value for K on the same line as their listing of the photocell.

Sekonic Speedmaster L-858D uses a silicon photo diode and has a K=12.5.

Results of r for a silicon photodiode:
• Raw silicon photodiode: 0.6 – 1.4
• Calibrated, filtered silicon photodiode: 0.9 – 1.1 (commonly quoted as about 0.8 – 1.2 in broader specs)

 

[Chan Tran]

Well, it was only an example of how the spectral sensitivity of the photocell can affect the value of K and evidence how K is a meter calibration constant and not an exposure adjustment. It wasn't intended to be a comprehensive review of all meters. In The Negative, Adams makes K sound like a conspiracy by the manufacturers.

My Pentax Digital Spot Meter has a silicon photodiode, as does the Minolta III according to their respective datasheets. Both have a K of 14. Interestingly, the Pentax datasheet has the value for K on the same line as their listing of the photocell.

View attachment 408635

Sekonic Speedmaster L-858D uses a silicon photo diode and has a K=12.5.

Results of r for a silicon photodiode:
• Raw silicon photodiode: 0.6 – 1.4
• Calibrated, filtered silicon photodiode: 0.9 – 1.1 (commonly quoted as about 0.8 – 1.2 in broader specs)

Adams thinks meter should be calbrated for K=1 in cd/ft^2 (which he mistakenly called it foot candle) and thus no K factor. Yah and he thought that was the meter manufacturers conspiracy to increase the percentage of good exposures.

 

[BrianShaw]

Adams thinks meter should be calbrated for K=1 in cd/ft^2 (which he mistakenly called it foot candle) and thus no K factor. Yah and he thought that was the meter manufacturers conspiracy to increase the percentage of good exposures.

That belief of Adams at that time is quite possibly because at the time the book was authored, he was successfully using a Weston Master II meter and those are its characteristics.

Perhaps it seemed more “scientific” to him or perhaps just because of familiarity??

 

[Chan Tran]

That belief of Adams at that time is quite possibly because at the time the book was authored, he was successfully using a Weston Master II meter and those are its characteristics.

Perhaps it seemed more “scientific” to him or perhaps just because of familiarity??

We can't tell what in his mind for sure. We can only guess. One thing he always preferred a light meter vs the exposure meter (a luminance meter) that readouts directly in Cd/ft^2 then using his so called "Exposure Formula" to come up with the settings. I don't think he cared so much for precise number as his Zone system has 10 Zone and Zone 5 is the middle. Well if you have 10 Zones then 5 is a little less than the middle. He doesn't have a Zone 0.

 

[BrianShaw]

At some point Adam’s opinion must have changed as the Pentax Digital Spotmeter has neither of those characteristics. Or he realized that it had nothing to do with employing his Zone system.

 

[DREW WILEY]

Adam's old SEI spotmeter once came up for sale for $30. Henceforward, he preferred the Pentax version. Since the dial of the Pentax has very conspicuous 1 EV increments (plus secondary 1/3 EV markings), with each of those corresponding to exactly one Zone in his method of appraisal, It's ridiculously simple to read the Zone range of any given scene.
Some people attach secondary little labels to the dial, which I find ridiculous. Just how hard is it to figure out that two
big marks on the dial below the central point equivalent to Zone V equates to Z III, for example, or that three marks above it equate to Z VIII ? Fred Picker added those stickers to both the modified and unmodified Pentax meters he sold, as well as selling the stickers by themselves. But whatever. ...

How much all of this had to do with his fabled mental footcandle calculation of the luminance of the moon at Hernandez, NM, when he couldn't find his meter in time, is a bit conjectural. He apparently knew that from memory, based on what an astronomer had told him, or maybe just by sheer trail and error experience with analogous moon scenes beforehand, or maybe with a bit of luck. I don't see how a Weston incident meter would have helped much, except for the shaded foreground portion of the scene. Then he decided on water bath development as kind of a Hail Mary pass to retrieve those low shadow values at ground level. It worked, sorta; but the result was awfully messy to print before he selenium intensified the foreground on the negative. I've seen a couple of the earlier versions.

 

[Chan Tran]

Adam's old SEI spotmeter once came up for sale for $30. Henceforward, he preferred the Pentax version. Since the dial of the Pentax has very conspicuous 1 EV increments (plus secondary 1/3 EV markings), with each of those corresponding to exactly one Zone in his method of appraisal, It's ridiculously simple to read the Zone range of any given scene.
Some people attach secondary little labels to the dial, which I find ridiculous. Just how hard is it to figure out that two
big marks on the dial below the central point equivalent to Zone V equates to Z III, for example, or that three marks above it equate to Z VIII ? Fred Picker added those stickers to both the modified and unmodified Pentax meters he sold, as well as selling the stickers by themselves. But whatever. ...

How much all of this had to do with his fabled mental footcandle calculation of the luminance of the moon at Hernandez, NM, when he couldn't find his meter in time, is a bit conjectural. He apparently knew that from memory, based on what an astronomer had told him, or maybe just by sheer trail and error experience with analogous moon scenes beforehand, or maybe with a bit of luck. I don't see how a Weston incident meter would have helped much, except for the shaded foreground portion of the scene. Then he decided on water bath development as kind of a Hail Mary pass to retrieve those low shadow values at ground level. It worked, sorta; but the result was awfully messy to print before he selenium intensified the foreground on the negative. I've seen a couple of the earlier versions.

I don't think he used his Weston meter in incident mode. He didn't like incident meter. His exposure formula to calculate the aperture and shutter speed is a lot more difficult to do than figure in your head the aperture and shutter speed from the LV value read from the Pentax meter.