Ilford Hp5+ @6400 in 510-Pyro

_T_ · Oct 22, 2023

If you took an average metering of the scene from the position of the lens or an incident metering from the position of the subject and told us the Ev it gives you for each shot we wouldn’t have to debate.

You could still meter the shot however you want to make the exposure, but if we had some indication of exactly how much illuminance we’re talking about then we would all be on the same page.

As it stands it’s impossible to draw any conclusions about the performance of the emulsion developer combination because, like Matt said, we could be looking at anything within a range of maybe even 4 stops of exposure. Your scene could be as much as 16x as bright as one might normally assume based on the shutter speed and aperture that you shot the picture at.

cerber0s · Oct 22, 2023

_T_ said:
If you took an average metering of the scene from the position of the lens or an incident metering from the position of the subject and told us the Ev it gives you for each shot we wouldn’t have to debate.

You could still meter the shot however you want to make the exposure, but if we had some indication of exactly how much illuminance we’re talking about then we would all be on the same page.

As it stands it’s impossible to draw any conclusions about the performance of the emulsion developer combination because, like Matt said, we could be looking at anything within a range of maybe even 4 stops of exposure. Your scene could be as much as 16x as bright as one might normally assume based on the shutter speed and aperture that you shot the picture at.

I can actually do that! I just picked up a lightmeter today, and I can easily recreate tabletop scene and light.

cerber0s · Oct 22, 2023

_T_ said:
If you took an average metering of the scene from the position of the lens or an incident metering from the position of the subject and told us the Ev it gives you for each shot we wouldn’t have to debate.

You could still meter the shot however you want to make the exposure, but if we had some indication of exactly how much illuminance we’re talking about then we would all be on the same page.

As it stands it’s impossible to draw any conclusions about the performance of the emulsion developer combination because, like Matt said, we could be looking at anything within a range of maybe even 4 stops of exposure. Your scene could be as much as 16x as bright as one might normally assume based on the shutter speed and aperture that you shot the picture at.

Here's the EV with the lightmeter flat on the table, pointing upwards towards the lamp. Pointing it downwards towards the table gives EV 9.1. Reflected light off the black camera reads EV 8.

pentaxuser · Oct 22, 2023

Steve@f8 said:
Thinking of trying HP5+ at 6400 myself, using Rodinal. From recollection the MDC indicates 52mins at 21C for 1:50, with agitation for 30s in 1st minute, then 10s every minute thereafter. That sounds a bit of a chore, I’m more inclined semi-stand. What do you think?
PS I like grain.

Steve, if you try semi-stand at presumably 1+100 then from the times given how will you decide what an IE of 6400 will need to be given that an EI of 800 is 60 mins at 24 C? I just have no idea what 60 mins turns into at 3 stops more
Can anyone help Steve@f8 here, assuming he needs help?

pentaxuser

_T_ · Oct 22, 2023

cerber0s said:
Here's the EV with the lightmeter flat on the table, pointing upwards towards the lamp. Pointing it downwards towards the table gives EV 9.1. Reflected light off the black camera reads EV 8.

View attachment 351605

If we’re being generous you exposed these shots at an ei of 400. One of them it appears that you exposed at an ei of about 100.

pentaxuser · Oct 22, 2023

_T_ said:
If we’re being generous you exposed these shots at an ei of 400. One of them it appears that you exposed at an ei of about 100.

What's the evidence for this and any idea why when he sets his ISO dial on his EOS 5 to 6400 and then uses the EOS 5 as he previously explained he is not shooting at what the dial and the meters tells him is an exposure at 6400

I am seeking information on what is now turning into a much more complicated issue and not issuing a direct challenge to you

It make me wonder what I am seeing when for instance Andrew O'Neill is showing us on his videos when he moves from HP5+ at box speed to 800 and then 1600

I use Andrew as an example simply because I recall his videos but plenty of others use what they term 1600 and some go to 3200

Thanks

pentaxuser

_T_ · Oct 22, 2023

I just used this calculator https://www.pointsinfocus.com/tools/exposure-settings-ev-calculator/

It gives you the ev required to make middle grey middle grey at a given shutter speed, aperture, and ei.

So what I’m saying is that based on the metered luminance of the scene, the aperture value and shutter speed at which the exposures were made, mathematically the ei used for one shot is about 400 and the other is about 100

cerber0s · Oct 22, 2023

_T_ said:
If we’re being generous you exposed these shots at an ei of 400. One of them it appears that you exposed at an ei of about 100.

Notice that the ISO on the lightmeter is set to 6400. If I set it to ISO 100 and take the same reading with the meter on the table, it shows EV 4.1. If I measure reflected light from the black camera at ISO 100 I get EV 1.4.

If I set the lightmeter to 6400 and f2.0 it gives me a shutter speed of 1/80, which is very close to what the camera gave me.

cerber0s · Oct 22, 2023

_T_ said:
I just used this calculator https://www.pointsinfocus.com/tools/exposure-settings-ev-calculator/

It gives you the ev required to make middle grey middle grey at a given shutter speed, aperture, and ei.

So what I’m saying is that based on the metered luminance of the scene, the aperture value and shutter speed at which the exposures were made, mathematically the ei used for one shot is about 400 and the other is about 100

This is how the lightmeter works. If you insert my shutter and apperture values in the table, and compensate for ISO, you’ll see that the math adds up pretty well. It shows that the scene was exposed at, or around, 6400.

It even adds up with your calculator. Entering my values in the calculator that you linked to, we get the EV for the scene, 2.33. This would be at ISO 100, so to get to 6400 we add 6 EV steps. 8.33 is pretty close to the 8 (7.9) that the lightmeter gave me.

_T_ · Oct 22, 2023

Those are not the values you gave in your earlier post. You said you shot at 1/180s at f4 and 1/90 at f2 which at 6400 would give an Ev of 5.33 and 2.33 respectively.

Your meter read the incident luminance at 10 Ev. That’s about a 5 stop difference.

But it’s clear from all this that you’re not metering properly as you came up with a value that is 8x as bright from one shot to the next of the exact same scene.

cerber0s · Oct 23, 2023

_T_ said:
Those are not the values you gave in your earlier post. You said you shot at 1/180s at f4 and 1/90 at f2 which at 6400 would give an Ev of 5.33 and 2.33 respectively.

Your meter read the incident luminance at 10 Ev. That’s about a 5 stop difference.

But it’s clear from all this that you’re not metering properly as you came up with a value that is 8x as bright from one shot to the next of the exact same scene.

My meter read 10 on the table (9 when facing down), that’s where I exposed at 1/180 at f4 (EV 5.33 according to your calculator). The meter read 8 when reading reflected light from the black camera, where I used 1/90 at f2 (EV 2.33).

Your calculator gives the EV for the scene at ISO 100. My meter gives the EV compensated for ISO. There’s 6 stops between ISO 100 and ISO 6400. Add 6 stops to 2.33 and you get 8.33.

_T_ · Oct 23, 2023

Yes so you over exposed by at least 6 stops. Thus your ei is not 6400 but 100 even though you’re metering at 6400

cerber0s · Oct 23, 2023

_T_ said:
Yes so you over exposed by at least 6 stops. Thus your ei is not 6400 but 100 even though you’re metering at 6400

I don’t think you’re reading it right. Take the EV 2.33 and plug it into the table above. That gives 1/4 at f1.0 at ISO 100. I used 1/90 at f2.0 which is roughly 6 stops LOWER than 1/4 at 1.0. But I developed for ISO 6400, which is 6 stops HIGHER than ISO 100.

npl · Oct 23, 2023

"I developped for ISO 6400"-> how do you know that ? I somewhat doubt that a 90min stand developement at 1:100 would give such a push, and it's debatable if it's even possible to push with stand dev and these very low dilutions.

Overdeveloping does nothing (or next to nothing ?) on the shadows, we extend developement to put the highlights at a higher level that was captured.

cerber0s · Oct 23, 2023

npl said:
"I developped for ISO 6400"-> how do you know that ? I somewhat doubt that a 90min stand developement at 1:100 would give such a push, and it's debatable if it's even possible to push with stand dev and these very low dilutions.

Overdeveloping does nothing (or next to nothing ?) on the shadows, we extend developement to put the highlights at a higher level that was captured.

I intended to develop for ISO 6400 then. And since the images came out somewhat OK, and since we (I, until someone can convince me otherwise) concluded that the film was indeed exposed at EI 6400, it seems like I wasn’t totally unsuccessful.

Also, 1:100 isn’t a low dilution with 510-Pyro, it’s the standard working dilutuion.

_T_ · Oct 23, 2023

cerber0s said:
I don’t think you’re reading it right. Take the EV 2.33 and plug it into the table above. That gives 1/4 at f1.0 at ISO 100. I used 1/90 at f2.0 which is roughly 6 stops LOWER than 1/4 at 1.0. But I developed for ISO 6400, which is 6 stops HIGHER than ISO 100.

Go to the calculator I posted and enter your actual numbers. You’re getting confused by the chart and your conversions

cerber0s · Oct 23, 2023

_T_ said:
Go to the calculator I posted and enter your actual numbers. You’re getting confused by the chart and your conversions

I did, and no, I’m not.

Look, by your reasoning; If I take my digital camera, set the ISO to 100, the shutterspeed to 1/90, and the apperture to 2.0, I should get an exposure very similar to the second photo of the cameras. Correct?

_T_ · Oct 23, 2023

No they wouldn’t look the same at all. You’re doing all kinds of fuckery trying to get your film speed to 6400.

But I think the issue is still with your metering method leaving room for confusion.

None of these conversations questioning your results would have happened if you simply metered the scene normally. Just stick the thing on average or something and then it won’t be such a difficulty to interpret your results.

cerber0s · Oct 23, 2023

_T_ said:
No they wouldn’t look the same at all

Why?

cerber0s · Oct 23, 2023

_T_ said:
None of these conversations questioning your results would have happened if you simply metered the scene normally

What is normal metering? I almost aleays use spot metering, if I at all have a camera with a meter, which I usually don’t.

If I turn the metering mode on the camera to average metering, it gives me 1/90 at f3.5. Very close to the 1/90 at f2.0 that I used.

grain elevator · Oct 23, 2023

Seems to me that _T_ is confusing EV and LV (or EV@100). BTW the metering method in the op can't account for 6 stops difference. I see no reason to believe the op didn't expose within at worst a stop or two of EI 6400.

pentaxuser · Oct 23, 2023

cerber0s said:
Why?

Yes I am interested in the answer to this as well

pentaxuser

_T_ · Oct 23, 2023

They wouldn’t look the same because the film is more sensitive than the iso 100 on your digital camera by 2 stops. And aren’t you pushing the development by 4 stops?

By normal I mean without the operator intervening in the placement of tones.

And I apologize for the disagreement over the online Ev calculator. I see that i was misunderstanding the values I was getting.

I checked it against my meter and you did shoot at 6400

pentaxuser · Oct 23, 2023

npl said:
"I developped for ISO 6400"-> how do you know that ? I somewhat doubt that a 90min stand developement at 1:100 would give such a push, and it's debatable if it's even possible to push with stand dev and these very low dilutions.

He surely knows that because his ISO film speed was set at 6400 and he observed the sequential change shutter speeds in accordance with that number of exposure stop changes

What is the evidence that stand development in any developer cannot give such a push. Is there a limit to pushing for stand that does not apply to "normal" development and if so what is it and is it based on actual trials or are you saying that the limit to pushing applies to any developer even if normally agitated?

Leaving aside Pyro 510 if I may for a moment, for which 1 + 100 is normal and turning to say Rodinal which at 1+100 is highly diluted the answer surely is to ensure that the minimum developer amount is met for 1 film which may be 5ml then does the dilution matter? I'd have logically thought not

I now note that you agree the OP did shoot at 6400 but I was composing my reply while you had already replied on this point My other questions are I believe still valid

Thanks

pentaxuser

cerber0s · Oct 23, 2023

_T_ said:
They wouldn’t look the same because the film is more sensitive than the iso 100 on your digital camera by 2 stops.

But then the same external lightmeter couldn’t be used for digital cameras, as for analog vameras.

_T_ said:
And I apologize for the disagreement over the online Ev calculator. I see that i was misunderstanding the values I was getting.

No worries, that happens

Ilford Hp5+ @6400 in 510-Pyro

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