A meter reading which perplexes me

David Lyga · Aug 19, 2020

First, do you mean "POST" (whereby you create a NEW THREAD) or "REPLY" where you simply respond to someone's already existing thread?

Assuming that you mean POST: you go to the general forum category that you want and on the top-right you will see "CREATE NEW POST". You enter a title for your thread, then you post what you want according to that general forum. - David Lyga

Arvee · Aug 19, 2020

CdS cells are more sensitive to the red/infrared part of the spectrum. Take your CdS camera and point it at an electric stove element that is on; you will notice a reading that you will not get with the SPD cell. Incandescent light sources will also cause a higher reading with CdS cell compared to SPD. Just different technology being more sensitive to one part of the spectrum than SPD technology; something to keep in mind when using CdS equipment.

Oddscy · Aug 19, 2020

thank you david

guangong · Aug 19, 2020

David Lyga said:
Semantics rules. The meter's film speed IS set lower but that does NOT indicate that the film is deficient in speed. Yes, it is purely semantics but I like to keep the theory intact.

The meter is set lower because the METER is not behaving and NOT because the film is not living up to its promises.

Semantics rules.

And, yes, I do remember dual film speeds. And that was the era of when developers could be kept in non airtight tanks with merely a floating cover to delay the onset of oxidation. And Kodak offered premixed developer not only in cans, but also with keys soldered onto those cans so one would not have to use the kitchen can opener to open them. I am very, very OLD. Remember, the year I was born Bette Davis stared in All About Eve and that was also the year that The Third Man (Joseph Cotten, Orson Wells, Alida Valli) opened in the USA. - David Lyga

You are very, very old. Good grief, I saw those films when they were first released. You are a young guy!
I was under the assumption that the spectrum of incandescent light lacked certain wavelengths and therefore some compensation was therefore necessary. Reminds me, I had a friend who manufactured a lightbulb that was close to sunlight and was used by architects who wanted plants and trees indoors.

David Lyga · Aug 19, 2020

guangong said:
You are very, very old. Good grief, I saw those films when they were first released. You are a young guy!
I was under the assumption that the spectrum of incandescent light lacked certain wavelengths and therefore some compensation was therefore necessary. Reminds me, I had a friend who manufactured a lightbulb that was close to sunlight and was used by architects who wanted plants and trees indoors.

You have made two points here which utterly amaze me. First, your age must go back to the caveman if you are OLD enough to be my parent!!!

Second, you know, maybe you are correct with assessing the speed of B&W film with regard to sensitivity to tungsten lighting. Maybe it really is slow under that light. THAT, compounded with the deficiency of the CdS meter just might work TOGETHER to make this film seeming to be even LESS sensitive. Interesting assessment, guangong. - David Lyga

Vilk · Aug 19, 2020

David Lyga said:
[...] I don't like having other than perfect equipment.

nothing new here: you want perfection, you'll need to do it yourself when my F2 metered heads started doing this, i replaced them with unmetered ones and moved on... hmmm, or did i move backwards? i guess in this case, if you keep in mind we came out of the garden and everything went downhill from there, backwards may be actually onwards

pentaxuser · Aug 19, 2020

David I have two meters which are about OK in the summer but always give me disappointing readings in nearly all of the winter months. I feel I need to name and shame them both on Photro. They are called Gas and Electricity meters

Anyone else experience similar problems with these two?

pentaxuser

Wallendo · Aug 19, 2020

pentaxuser said:
David I have two meters which are about OK in the summer but always give me disappointing readings in nearly all of the winter months. I feel I need to name and shame them both on Photro. They are called Gas and Electricity meters

Anyone else experience similar problems with these two?

pentaxuser

Here is the South my gas meter doesn't work at all in the summer.

In the winter, both go up. My wife turns on the gas logs, gets too hot, and then turns on the air conditioning. She seems to be focused on creating global warming.

Sirius Glass · Aug 19, 2020

Wallendo said:
Here is the South my gas meter doesn't work at all in the summer.

In the winter, both go up. My wife turns on the gas logs, gets too hot, and then turns on the air conditioning. She seems to be focused on creating global warming.

Not here. Some of us cook with gas.

KenS · Aug 19, 2020

OH.......the 'joys'"of using only large format cameras that don't need batteries 'installed', comes to 'light'...[no pun intended ] My Pentax spot-meter in its 'pouch/holster' on my belt means more 'space' in my camera bag.

Ken

David Lyga · Aug 19, 2020

pentaxuser said:
David I have two meters which are about OK in the summer but always give me disappointing readings in nearly all of the winter months. I feel I need to name and shame them both on Photro. They are called Gas and Electricity meters

Anyone else experience similar problems with these two?

pentaxuser

What, yet! ANOTHER dimension to this quandary? What next? Do meters ever behave? Both gas and electricity are going to have to get their ISOs in order. - David Lyga

MattKing · Aug 19, 2020

After looking a bit through data sheets and other information, I note with interest that the current 400TX/Tri-X datasheet does not include any ISO information.
The spectral sensitivity curve is interesting though.

David Lyga · Aug 19, 2020

MattKing said:
After looking a bit through data sheets and other information, I note with interest that the current 400TX/Tri-X datasheet does not include any ISO information.
The spectral sensitivity curve is interesting though.

I swear (anyone correct me if I err) that the Tri-X of decades past is NOT the Tri-X of today. Today's Tri-X has less toe and shoulder, is more red sensitive, and, generally, NOT a film to avoid using outdoors. It really WAS a film that one did not often use outdoors back in the 50s and 60s and even 70s because the results were usually drab outdoors. It has more brilliance today. Do I err here? - David Lyga

MattKing · Aug 19, 2020

It certainly has changed a lot, but I certainly liked using it in the 1970s - both indoors and outdoors.
This is mostly 1970s Tri-X.

I wish that 1970s Tri-X offered the same fine grain that the current stuff does.

David Lyga · Aug 19, 2020

I have to say that that is rather good. Maybe I did not use it like I should have. - David Lyga

benjiboy · Sep 25, 2020

Arvee said:
CdS cells are more sensitive to the red/infrared part of the spectrum. Take your CdS camera and point it at an electric stove element that is on; you will notice a reading that you will not get with the SPD cell. Incandescent light sources will also cause a higher reading with CdS cell compared to SPD. Just different technology being more sensitive to one part of the spectrum than SPD technology; something to keep in mind when using CdS equipment.

I agree with this it's probable cause is a question of the difference of spectral response of CdS and SPD cells.

A meter reading which perplexes me

David Lyga

Arvee

Oddscy

guangong

David Lyga

Vilk

pentaxuser

Wallendo

Sirius Glass

KenS

David Lyga

MattKing

Moderator

David Lyga

MattKing

Moderator

David Lyga

benjiboy

A meter reading which perplexes me

Moderator

Moderator

Privacy & Transparency

Privacy & Transparency