KODAK PLUS-X Reversal Film 7265 Question

[Lunar07]

Question: what happens if you have an advanced camera that will read the 250 speed notch, and you cut a filter notch in the Tri-X cartridge? Answer: The speed will be registered as 250 ASA.

NO! See, this is the confusion that arises when you associate notching with the tungsten speed. TriX is notched for 160D/250T. If you cut a filter notch in TriX, the compliant ADVANCED camera will read it at 160 with filter setting in Daylight. Since filter pin is out and filter is engaged in this setting, this will correspond to 250 + filter correction. Camera IS metering for 160 ASA. <b>160 happens to be the Exposure Index (EI) of 250 when used with the 85 filter - SO, 250 is the tungsten rating of the 0.4" upper notch.</b> At no stage whatsoever is the camera metering for 250 at filter setting of daylight. Think DAYLIGHT notch equivalent with filter set to Daylight.. Build your case on what is being metered from there. NOW, switch filter key to B. Camera will now remove filter from path and meter for the upper end of the ASA and closes aperture by 2/3 of a stop. Metering for 250.

That's basically what I'm saying, though, isn't it? With a filter notch, and the speed notch reading at the .4 notch distance, the advanced camera will read Tri-X with no filter in path at 250. I meant with no filter-- no nothing.

Sure. In this case, filter setting is at B.

But, isn't what actually is happening is that the filter switch just throws in a 2/3 stop compensation, so you're getting an effective film speed of 160 at the 'daylight' setting? I mean, remember, the only way you're going to get that 160 with the switch at "daylight" is to have the filter in place-- because you've cut a filter notch in the camera.

I do not know if the camera is adjusting because the 85 filter is in the path, or because the camera is instructed to meter with a daylight rating read straight from the upper notch. Different cameras may handle it differently. Some cameras will take it for granted that there is an 85 filter there. Some cameras (Type D ones) may decide to meter at the daylight reading as long as the filter switch is at SUN.
Thing is: I do not know, and I do not care to know, and it does not matter to know what is actually happening beneath the cover.

Consider these cases A and B:
A. With a filter notch, you throw the switch to B. Camera closes by 2/3 of a stop. Is it metering at 160 then factor in a stop down of 2/3 OR is it metering at 250?
B. With a filter notch, throw switch to SUN. Is the camera metering for 250 + filter correction, or is it metering at 160.
You see, these are all rhetorical questions.
What I know is this:
In the former case A it meters at 250.
In the latter case B it meters at 160.

This is the crucial information that we need to know.

In other words, imagine that this camera has a manual ASA knob. In case A you set this control to 250. In case B you set to 160.
This is what the camera is metering for.
What is happening behind the hood is great to know, but this is another subject altogether.

It seems to me that's what's happening in general, by design, is that without the filter pin in, the SMPTE compliant cameras are designed to always meter the maximum ASA rating of the film-- or what the speed notch tells it (if they can.) But with the filter pin in, the lower ASA 2/3 stop complement of the speed notch spec. is automatically metered-- up to whatever the camera can do, which in many cases is 100 ASA. That's why, as I understand it, many SMPTE compliant cameras have a problem with a notchless Tri-X cartridge, because they read it at ASA 100. They can't go any higher when the filter pin is pushed in.

Putting aside the issue that smpte cameras can not go higher than 100 - what you state is equivalent to saying that filter pin IN or OUT at switch SUN, meters at exactly the same ASA. So why the over worked approach of ASA's adjusted by 2/3 when the number is already given to you: the daylight rating.
My experience with smpte type D cameras tells me that the camera does not give a hoot when you press filter pin IN with switch at SUN. It is like nothing happens. There is no electrical activity to compensate for anything. It goes on its merry way metering for the daylight rating. This is what the Moviflex does. So does the Nizo 6080. They assume that there is an 85 filter. This is a part of the standard around which this system is built. So there is no reason to do anything with these compliant cameras. Why should a camera adjust anything (when you press filter pin IN at switch setting SUN) when the net result is the same exact metering at the same ASA. It just does not make any sense.

As for the trouble metering more than 100 ASA with compliant cameras. I did not know that, but I bet you that compliant advanced cameras that can meter up to 400 ASA do it the very same way. Meter at lower end with SUN setting regardless of filter notch. In other words, smpte compliant cameras extend their ASA's while sticking to the general principle.

Some can, though. How does the 6080 Nizo read the notchless Tri-X cartridge? I suspect at 160 (?) That makes sense-- it fits the prescription: the depressed filter pin sets the meter to the 2/3 stop complement of the speed notch ASA, and the 6080 can read what in most cases would be called these "daylight" speeds (the lower complement) much higher than 100 ASA.

Filter Pin IN does not cause any compensation to metering. It follows the smpte system. To cause a compensation in metering AND remove filter, you have to have filter pin OUT, and set switch to B.
With filter switch at SUN, camera is reading the daylight rating as sensed from upper notch.
Regardless from inner workings and regardless of any compensation that you can talk of: camera ends up metering at the lower ASA end with switch set to SUN. Meaning - daylight rating.

[Lunar07]

Simply put, in a notched cartridge, because 250 is the 'primary' higher ASA of Tri-X, the speed notch takes over when the filter pin is released, regardless of the tungsten/daylight distinction. Sure, you can toggle back and forth with the filter switch, but the top ASA of the speed notch (or whatever the camera will read of the notch) becomes the primary "read" ASA without the filter switch on daylight. Isn't that what's really going on here in general?

You are complicating the issue needlessly. Simply put:
With a filter notch in cart, filter pin is OUT.
With filter in path (SUN setting), camera meters at daylight rating.
With filter out of path (B setting), camera closes 2/3 of a stop, metering for upper end (Tungsten rating) of ASA.
I do not understand your observation "Sure, you can toggle back and forth with the filter switch, but the top ASA of the speed notch (or whatever the camera will read of the notch) becomes the primary "read" ASA without the filter switch on daylight."
Toggling filter switch with filter pin OUT, causes camera to meter from low end of ASA (SUN setting) to high end of ASA (B setting).

You are mixing between inner workings of camera (how it is setting the exposure system etc....) and THE ACTUAL ASA camera is METERING at.

With filter set to SUN, you observe following (at least with cameras I tested) on compliant cameras:
pressing and releasing filter pin does not change the aperture. Not only that, the camera does not seem to be adjusting anything. It is as though the camera did not care that filter pin IN removed filter from path. To me, this suggests one and only one thing: camera meters at daylight rating read from upper notch. And pressing filter pin IN and OUT removes and engages filter from path without the camera caring.

[Jim Carlile]

I do not know if the camera is adjusting because the 85 filter is in the path, or because the camera is instructed to meter with a daylight rating read straight from the upper notch. Different cameras may handle it differently. Some cameras will take it for granted that there is an 85 filter there. Some cameras (Type D ones) may decide to meter at the daylight reading as long as the filter switch is at SUN.
Thing is: I do not know, and I do not care to know, and it does not matter to know what is actually happening beneath the cover.

Actually, I think it's important to understand how the camera is working. It's kind of like the shutter speed formula: if you understand how it works and what it is doing, you'll always know how to use it.

For instance-- when the filter pin is pushed in by a notchless cartridge, the filter will always be displaced from the light path. There won't be any 85 filter there with a notchless cartridge. But instead of cancelling the 2/3 filter factor that the meter adjusted for when the user moved the slide switch to "daylight," the SMPTE compliant camera keeps the 2/3 iris increase no matter what, when the filter sensor pin is depressed and the filter switch is at "daylight."

Consider these cases A and B:
A. With a filter notch, you throw the switch to B. Camera closes by 2/3 of a stop. Is it metering at 160 then factor in a stop down of 2/3 OR is it metering at 250?
B. With a filter notch, throw switch to SUN. Is the camera metering for 250 + filter correction, or is it metering at 160.
You see, these are all rhetorical questions.
What I know is this:
In the former case A it meters at 250.
In the latter case B it meters at 160.

This is the crucial information that we need to know.

If you know why it's doing this, it's easy to figure out what to do every time and with every stock, with every camera. With a filter notch, the pin is never in. Thus, the 'b' setting (filter out) will always read the cartridge ASA at the top speed-notch distance--whatever the camera will read, 160, or possibly 250 if it's an advanced camera. With the filter switch thrown to "daylight", the filter is in the path, and thus the meter opens by 2/3 stop to give an effective equivalent ASA of 2/3 stop lower (100, 160, whatever.) But that's because-- and only because-- the 85 filter is in the path, if the cartridge has a notch in it.

See, that's why it's happening, and I personally think it's more than just a rhetorical question. It makes a BIG difference depending on what kind of film you're using, even B/W, to know if your effective film speed is being determined with or without an 85 inline filter, and if the filter pin is being depressed by a notchless cartridge..

Putting aside the issue that smpte cameras can not go higher than 100 - what you state is equivalent to saying that filter pin IN or OUT at switch SUN, meters at exactly the same ASA. So why the over worked approach of ASA's adjusted by 2/3 when the number is already given to you: the daylight rating.
My experience with smpte type D cameras tells me that the camera does not give a hoot when you press filter pin IN with switch at SUN. It is like nothing happens. There is no electrical activity to compensate for anything. It goes on its merry way metering for the daylight rating. This is what the Moviflex does. So does the Nizo 6080. They assume that there is an 85 filter. This is a part of the standard around which this system is built. So there is no reason to do anything with these compliant cameras. Why should a camera adjust anything (when you press filter pin IN at switch setting SUN) when the net result is the same exact metering at the same ASA. It just does not make any sense.

The camera is not adjusting anything. What it's doing is keeping the same reading that you had with the filter in place at the daylight setting, only without the filter. This distinction is crucial, because it's the difference between SMPTE compliant cameras and the others. What's important is knowing why it's the same exact reading, because in many cameras, it's not. Sure, you can figure things strictly by experimentation or rule of thumb, but knowing exactly why the camera is doing what it's doing will, I think, make things easier in the long run. Maybe it's just a philosophical thing...

Filter Pin IN does not cause any compensation to metering. It follows the smpte system. To cause a compensation in metering AND remove filter, you have to have filter pin OUT, and set switch to B.
With filter switch at SUN, camera is reading the daylight rating as sensed from upper notch.
Regardless from inner workings and regardless of any compensation that you can talk of: camera ends up metering at the lower ASA end with switch set to SUN. Meaning - daylight rating.

First of all, filter pin in does cause a compensation to the metering in SMPTE compliant cameras. That's the whole idea-- the camera reads the speed notch as the film's ASA, and when the filter pin is pushed in, the metering stays open the 2/3 stop to "compensate" for the "lower" rated ASA--without the filter in place (when the filter switch is at "daylight" position.) It's not really "reading" the lower ASA either-- it's still reading the speed notch, but opening up the iris by 2/3 stop, without the need for the filter to be inline.

That 2/3 differential stays in place through all the exposure readings, as long as the filter pin is pushed in and the filter switch is set to daylight. I mention this because that's what's really happening-- the meter doesn't just shift to some different exposure scale when the pin is depressed. It's still reading the film at the high ASA, but just throwing in a continuous 2/3 stop change-- which effectively lowers the ASA to the 'low' film speed rating.

It's not a matter of tungsten vs. daylight. It's a matter of high rating and low rating. Most of the time the high rating will be tungsten-- but not always, as we see with Ektachrome 100D and Plus X 100D. But the camera, by design is tungsten centric. It either has to have the filter pin pushed in order to rate "daylight" film ratings (SMPTE compliant cameras only,) or the filter switch pushed to daylight, with the 85 filter inline.

When you look at the big picture, everything falls into place. It also explains why Kodak notches Tri-X at 250T (so I'm told-- I've never used the new Tri-X, but this would make sense, because even though Tri-X is rated at 200 ASA, there's no speed notch for 200.).

The advanced camera will read the speed as 250 ASA (not 200,) but the notchless cartridge pushes the pin in, thus opening up the iris by 2/3 stop from 250, giving the effective film speed as 160, which is appropriate for Tri-X. By necessity, Kodak must speed notch this film at 250, because on SMPTE compliant cameras, any smaller speed-notch size (160 is the next one down) would by design add the 2/3 stop adjustment when the filter pin is pushed in.

Older or more limited SMPTE compliant cameras can't read high ASA's. Thus the exposure would be way off, because they would be rating Tri-X as a ridiculous 100 ASA with that notchless B/W daylight cartridge. So, that's why Kodak speed notches Tri-X the way it does. And it only works for advanced cameras that read high ASA's. Otherwise, it would be easier for everyone if they just notched it at 160 and kept it simple!

[Jim Carlile]

I do not understand your observation "Sure, you can toggle back and forth with the filter switch, but the top ASA of the speed notch (or whatever the camera will read of the notch) becomes the primary "read" ASA without the filter switch on daylight."
Toggling filter switch with filter pin OUT, causes camera to meter from low end of ASA (SUN setting) to high end of ASA (B setting).

You are mixing between inner workings of camera (how it is setting the exposure system etc....) and THE ACTUAL ASA camera is METERING at.

If you cut a notch in the notchless Tri-X cartridge, the filter switch by design will make all cameras put an 85 filter in the light path when the switch is set to "daylight." If it's not set to daylight, but to bulb instead, there is no filter. Thus, the meter will read whatever the speed notch is cut for-- or whatever maximum ASA it can read-- when switch is at bulb. This is true of all S8 cameras.

If you swing the switch to daylight, the filter flies into place, and the meter automatically bumps up 2/3 of a stop, giving an effective reading of 2/3 stop bigger for all iris readings, or an equivalent of 160 ASA in the case of Tri-X film. But the film is still 200 ASA (or 250, whatever.) It's not 160-- the film is merely rated at 160 because it acts as if it's 160 with the 85 filter in place.

In fact, technically, in all cameras the meter is never reading at the lower ASA- it always reads at the speed notch (or whatever it can read of the speed notch) and is merely opening up 2/3 stop when the switch is at daylight, at any and all exposure readings. When it does that, it's functionally the same thing as reading the lower ASA.

This whole notion is key to the difference between SMPTE compliant and non-compliant cameras. With compliant cameras, when the filter pin is pushed in, the "daylight" filter is removed but the 2/3 filter factor is never cancelled. With non-compliant cameras, both the filter and the factor that were inserted into the path by the "daylight" filter switch are removed.

This is what's actually happening, and IMO when you think of it this way, this general picture, everything falls into place and it all makes perfect sense. It's not a matter of tungsten vs. daylight, because the higher speed rating can be either, depending on the film.

Here's what it all boils down to: The camera is always metering at the speed notch-cutting size (or whatever it can read of it-- depends on the camera how high it will go.) But it has various ways of throwing in a 2/3 stop adjustment. Some are useful, some are not-- especially if you have daylight film and the only way you can get what you think are the correct exposure readings you want is if you throw the filter switch. That's what a non-compliant type 'G' camera cannot do, and that's why it cannot read daylight films correctly.

A compliant camera can read some daylight films well, and type 'A' films too. But if the compliant camera is an older model, and it cannot read above a certain daylight ASA level, then it's going to have problems with Tri-X. That's because the particular way the SMPTE camera reads and registers daylight films will conflict with the way it needs to read Tri-X as a daylight film at 200+ ASA. It can't go that far up the daylight ASA scale, and because of that, it will misread Tri-X as a daylight film far lower than it is.

[Lunar07]

If you know why it's doing this, it's easy to figure out what to do every time and with every stock, with every camera. With a filter notch, the pin is never in. Thus, the 'b' setting (filter out) will always read the cartridge ASA at the top speed-notch distance--whatever the camera will read, 160, or possibly 250 if it's an advanced camera. With the filter switch thrown to "daylight", the filter is in the path, and thus the meter opens by 2/3 stop to give an effective equivalent ASA of 2/3 stop lower (100, 160, whatever.) But that's because-- and only because-- the 85 filter is in the path, if the cartridge has a notch in it.

See, that's why it's happening, and I personally think it's more than just a rhetorical question. It makes a BIG difference depending on what kind of film you're using, even B/W, to know if your effective film speed is being determined with or without an 85 inline filter, and if the filter pin is being depressed by a notchless cartridge..

I do not know what the argument is all about anymore. We are essentially saying the same exact thing.
I see now where the misunderstanding is coming. You start your measurement with filter switch at B. So of course there is a difference in +2/3 when you switch to SUN. I start with filter switch at SUN then adjust by -2/3 of a stop switching to B.
It is better to start the test and adjustments with filter switch to SUN.
Reason is that MOST cameras will actually press filter sensor IN when filter switch is at B. Other than that you are rephrasing what I have been saying all alone word by word but with you starting at setting B.

First of all, filter pin in does cause a compensation to the metering in SMPTE compliant cameras. That's the whole idea-- the camera reads the speed notch as the film's ASA, and when the filter pin is pushed in, the metering stays open the 2/3 stop to "compensate" for the "lower" rated ASA--without the filter in place (when the filter switch is at "daylight" position.) It's not really "reading" the lower ASA either-- it's still reading the speed notch, but opening up the iris by 2/3 stop, without the need for the filter to be inline.

This is actually just an issue of perspective.
All I need to know is that camera meters at lower end with filter set to SUN, and at higher end with filter set to B. When you switch to B with filter sensor OUT, camera adjusts by closing aperture by -2/3. You may say, well no actually camera is now reading directly from notch and setting the exposure at some CORRECT reading without adjusting. Different cameras may handle it differently for all I know.
This is an issue of perspective.
Point is: however you want to reach it is up to you. To me it makes more sense to base my calculations from a daylight perspective.
In an earlier post I quoted a Kodak guy in Austin who worked on Super8 long ago. He insists that it is the daylight rating that takes precedence in these calculations. We are reaching the same conclusions basically. I tend to take the daylight rating. So all my tests start with:
a. Filter set to SUN, and
b. Filter sensor OUT.
and take it from there to establish if a camera is Type D (daylight camera or smpte compliant).

To me, starting a test from switch set to B where the filter sensor is already pressed IN is not a good starting point then base my calculations on a tungsten perspective.
You are entitled to your perpective We are reaching the same conclusions whatever perspective you choose.

It's not a matter of tungsten vs. daylight. It's a matter of high rating and low rating. Most of the time the high rating will be tungsten-- but not always, as we see with Ektachrome 100D and Plus X 100D. But the camera, by design is tungsten centric. It either has to have the filter pin pushed in order to rate "daylight" film ratings (SMPTE compliant cameras only,) or the filter switch pushed to daylight, with the 85 filter inline.

From what I know - Super8 is daylight centric at its heart. It is tungsten centric due to consumer pressure of what was produced and sold. On the long run this is more of a philosophic question that takes knowledge of the history and economic factors. Kodak, in its table, is a clear indication that the daylight rating was there from the very start.
Again, to argue that a camera reaches the daylight rating via an aperture opening adjustment of 2/3 stop or to argue that actually it is reaching the tungsten rating via an aperture closure of 2/3 stop is a TOTALLY rhetorical question that depends on perspective.

[Lunar07]

If you swing the switch to daylight, the filter flies into place, and the meter automatically bumps up 2/3 of a stop, giving an effective reading of 2/3 stop bigger for all iris readings, or an equivalent of 160 ASA in the case of Tri-X film. But the film is still 200 ASA (or 250, whatever.) It's not 160-- the film is merely rated at 160 because it acts as if it's 160 with the 85 filter in place.

Again, this is an issue of perspective. You are basing your calculations on the higer end of the ASA. I base them on the lower end with filter switch to SUN.
In a compliant OR non-compliant camera, the POPULAR default is a cart with a filter notch. If camera has a filter notch sensor, then it has, in most cases a filter socket or a filter key with filter inline. So, out of the box, in 99.99% of cases, camera is metering AT the lower end - the daylight rating, out of the box. So, to me it makes sense to start calculating from this point.
<b>Also, I never said that the film is 160. I wrote: In an advanced compliant camera, if you cut a filter notch in TriX, the camera is metering at 160 with filter switch set to SUN. Which HAPPENS to be the daylight notch speed of the cart AND the EI of 250 + 85 filter correction. <i>I truly do not know why you are misquoting me!</i></b> (maybe you misunderstood what I wrote.)
In the notch system anyway: The daylight rating is always the EI of the tungsten rating + 85 filter correction.
Then I said: camera is metering at 160 (NOT FOR 160). To you it is metering at 250 + 2/3 of a stop.
Whether system is based on daylight then -2/3 (as i see it) or tungsten then + 2/3 : I do not know, and I do not have much information on how cameras handle this. You do not know, and you do not have definite information. And to tell you the truth: I personally do not care to know
To me: such a discussion is rhetorical and goes nowhere at this stage.
You can reach your values anyway you like. To me it was always an issue of perspective. We are both reaching the same conclusions. My preference has always been to start with the daylight rating.

[Jim Carlile]

Hi Lunar-- no, I wasn't citing you in the above, but more the general idea over the years that the ASA rating of the film somehow becomes an actual lower rating once the 85 filter is in place or the filter pin is depressed.

The film continues to be rated at the speed notched ASA, it's just that the 2/3 stop difference-- however it comes about-- creates an effective 2/3 stop ASA change; that is, the film is now treated as if it were a 160, or whatever. But it's not, it's still 200, or 64, etc., and it's still being read by the meter at the original ASA. Usually the notched speed is for tungsten light, but it doesn't have to be.

The reason I mention this is that there's always been this talk that the meter somehow "sets" the daylight rating to 160 or 100 or that a new meter scale is somehow involved, and it's not that complicated. The lower "daylight" ASA's are just an equivalent ASA in terms of light sensitivity, created by the 2/3 stop change.

Actually, even the top speed-notched ASA is just an approximation, but that's a whole different story... but you're right, we're saying the same thing in different ways. For me it is easier to see the big picture as the camera being not so much tungsten-centric, but speed-notch centric, and then look at what happens when daylight conditions require it to adjust.

What Kodak could have done is speed notch every film for every different ASA, and like R8, just sell a variety of separate tungsten and daylight films, and then be done with it. But they didn't. They had to be clever about it!

[aj]

Sure people with good typing skills in discussion
Brings back memories of the EMJ writings (in length, only).

Any chance of a brief summary to conclude the thread?

[Jim Carlile]

Here it is in a nutshell:

Cameras are 'speed-notch' centric: every film cartridge has a speed notch size and it is always the "high" ASA rating. The exposure meter reads this ASA speed and sets itself accordingly.

When type 'A' film is used in daylight, camera swings a #85 color correction filter into place, this reduces exposure by 2/3 stop but meter adjusts iris by the same amount to compensate for the loss. This 2/3 loss for all readings reduces the "high" ASA of the film to a lower effective rating, but the film is still being read by the camera at the notched setting. That's where they get the idea of a higher/lower ASA for the same film.

Kodak designs the S8 system to read all films the same way. Most films are tungsten sensitive and need the 85 for daylight shooting. But what about "daylight" sensitive films that don't need or want an 85 filter in the light path? By design and for simplicities sake, Kodak has rated daylight-sensitive stocks at the same ASA rating as the daylight equivalent of the type 'A' stocks; the "lower" rating. So how does the camera read this lower ASA rating?

Some cameras remove the filter with a daylight cartridge, and automatically cancel the difference and bump the exposure back up 2/3 stop. They do this because at one time there was a color filmstock that Kodak wanted to be always rated at 160 ASA without the 85 filter, not 2/3 stop lower.

But this is no good for lower ASA daylight sensitive films, like Ektachrome D or the New Plus-X 100D. Others cameras work differently-- they remove the filter, but keep the exposure the same 2/3 stop larger, as if the filter were still in place, as long as the filter switch is on daylight. This allows cameras to correctly meter daylight film without an 85 filter in the way. The camera is treating the film as if it is rated at the lower ASA speed instead of the higher- which it is!

The first group cannot rate most daylight film stocks correctly, because they can only rate them at the higher type "A" ASA rating without that 85 filter. But the second group are designed to rate daylight stocks at the film's lower effective ASA without the need for a filter in order to do so, and this is fine. And this works for every speed notch, 250/160, 160/100, 64/40. The daylight sensitive films will always be rated at or near this lower number. The notch cuts the high speed, the filter pin in' effectively adjusts the meter to the low speed without the 85 filter. It's ingenious.

The way they do this is simple: the daylight cartridge pushes in the filter pin, which disables the 85 filter (put into place by the "daylight" filter switch setting.) But when the pin is pushed in, the meter, by design, keeps the 2/3 stop correction. In effect, pushing in the filter pin tells the camera that this is a daylight cartridge and the lens iris is still to be opened up 2/3 stop more than what the speed notch would otherwise indicate.

Because the speed notch is always cut for the high ASA, and the lower effective daylight ASA is always the same 2/3 stop lower than the high (by design,) this correctly adjusts the iris for all further readings with the daylight sensitive film.

[Lunar07]

Sure people with good typing skills in discussion
Brings back memories of the EMJ writings (in length, only).

Any chance of a brief summary to conclude the thread?

Sure. Coming up in a new thread, later today
Entitled: Metering, and the Three Broad Categories of Cameras ( really :-D )
It is an important subject and it is worth a good summary writeup.

[Jim Carlile]

Good-- I think this thread has effectively exhausted itself! On to specifics!!

[Lunar07]

But this is no good for lower ASA daylight sensitive films, like Ektachrome D or the New Plus-X 100D. Others cameras work differently-- they remove the filter, but keep the exposure the same 2/3 stop larger, as if the filter were still in place, as long as the filter switch is on daylight. This allows cameras to correctly meter daylight film without an 85 filter in the way. The camera is treating the film as if it is rated at the lower ASA speed instead of the higher- which it is!

AJ asked for a nutshell -
You are describing a D Type camera -
With filter at SUN setting, camera will meter at the lower ASA end of the notch speed - as sensed by camera ( and as listed in Kodak table) -<b>regardless</b> of filter sensor position.

This is what I call a D Type smpte compliant camera in a nutshell

I'll write a summary this evening.

[jellybean]

I'll write a summary this evening.

I realize this thread is very old, but i have a few questions i would like to find out from very experienced people like you. I tried reading this thread and all i got was a bunch of words jumbled up in my head.

So, I have a Braun Nizo S560 and i plan to shoot expired Tri-X 7278, Plus-X 7276, Vision3 50D, and Vision3 500T.

What would be the correct way to expose these films?? I am so confused on this topic so it would be great if you can help me out. Thanks in advanced!

[Lunar07]

I do remember this thread. For those who followed it step by step, it was quite informative.
Of course, I never wrote the summary
I agree with you, for someone reading the thread as a whole, it looks like a jumble.
I'll get back with you on your questions tomorrow.

I'll write a summary this evening.

I realize this thread is very old, but i have a few questions i would like to find out from very experienced people like you. I tried reading this thread and all i got was a bunch of words jumbled up in my head.

So, I have a Braun Nizo S560 and i plan to shoot expired Tri-X 7278, Plus-X 7276, Vision3 50D, and Vision3 500T.

What would be the correct way to expose these films?? I am so confused on this topic so it would be great if you can help me out. Thanks in advanced!