I'm a layman wondering if (generally speaking) increasing the ISO setting
increases sensitivity to infrared light.

Thanks.

On 15/05/2021 04:48, John Doe wrote:
> I'm a layman wondering if (generally speaking) increasing the ISO setting
> increases sensitivity to infrared light.
>
> Thanks.

Simple answer: No.

--
Cheers,
David
Web: http://www.satsignal.eu

In article <s7ngav$r2u$1@dont-email.me>, John Doe
<always.look@message.header> wrote:

> I'm a layman wondering if (generally speaking) increasing the ISO setting
> increases sensitivity to infrared light.

increasing iso simply amplifies the signal, regardless of wavelength.

On 2021-05-14 23:48, John Doe wrote:
> I'm a layman wondering if (generally speaking) increasing the ISO setting
> increases sensitivity to infrared light.

Yes of course it does - at least to near infrared and possibly further.
But most cameras have an IR filter over the sensor blocking those
wavelengths.

--
"...there are many humorous things in this world; among them the white
man's notion that he is less savage than the other savages."
-Samuel Clemens

On 15/05/2021 22:45, Alan Browne wrote:
> On 2021-05-14 23:48, John Doe wrote:
>> I'm a layman wondering if (generally speaking) increasing the ISO setting
>> increases sensitivity to infrared light.
>
> Yes of course it does - at least to near infrared and possibly further.
> But most cameras have an IR filter over the sensor blocking those
> wavelengths.

But increasing the ISO does not typically increase the sensitivity - the
signal-to-noise ratio - it just increases the gain. The blocking filter
needs to be removed (not a trivial task) to increase the (relative)
sensitivity to (near) infra-red light. Hence my answer of "No".

--
Cheers,
David
Web: http://www.satsignal.eu

On 2021-05-16 01:14, David Taylor wrote:
> On 15/05/2021 22:45, Alan Browne wrote:
>> On 2021-05-14 23:48, John Doe wrote:
>>> I'm a layman wondering if (generally speaking) increasing the ISO
>>> setting
>>> increases sensitivity to infrared light.
>>
>> Yes of course it does - at least to near infrared and possibly further.
>>    But most cameras have an IR filter over the sensor blocking those
>> wavelengths.
>
> But increasing the ISO does not typically increase the sensitivity - the
> signal-to-noise ratio - it just increases the gain.  The blocking filter
> needs to be removed (not a trivial task) to increase the (relative)
> sensitivity to (near) infra-red light.  Hence my answer of "No".

Splitting hairs. As a system, increasing ISO increases the system
sensitivity. Gain is sensitivity no matter where applied. If there are
noise consequences, then so be it.

And of course signal to noise ratio ≠ sensitivity. It's a measure of
quality and goes to system bandwidth.

And while, for a certain range of ISO, the gain is numeric, some sensors
have analog gain at the sensor chip pushing the gain closer to where the
signal was obtained.

So not a definite no, just something requiring a clear answer with more
facts.

--
"...there are many humorous things in this world; among them the white
man's notion that he is less savage than the other savages."
-Samuel Clemens

On 16/05/2021 12:36, Alan Browne wrote:
> Splitting hairs. As a system, increasing ISO increases the system
> sensitivity. Gain is sensitivity no matter where applied. If there are
> noise consequences, then so be it.
>
> And of course signal to noise ratio ≠ sensitivity. It's a measure of
> quality and goes to system bandwidth.
>
> And while, for a certain range of ISO, the gain is numeric, some sensors
> have analog gain at the sensor chip pushing the gain closer to where the
> signal was obtained.
>
> So not a definite no, just something requiring a clear answer with more
> facts.

Although likely beyond the range of an answer for a "layman", as
originally requested!

It is encouraging that sensors today are much nearer than they used to
be to the shot/photon noise limited level. A good big sensor will
always beat a good small sensor! More photons.

Having said that, I've been very pleased in recent times with the
ability of my Google Pixel phone to have stacking inbuilt, and achieving
results which exceed what my eyes can see. It works very well. Since
having a decent phone I've done much more photography.

--
Cheers,
David
Web: http://www.satsignal.eu

In article <s7r5e0$6va$1@dont-email.me>, David Taylor
<david-taylor@blueyonder.co.uk.invalid> wrote:

> It is encouraging that sensors today are much nearer than they used to
> be to the shot/photon noise limited level.

they've been at that level for quite some time.

> A good big sensor will
> always beat a good small sensor! More photons.

all things being equal, yes.

the problem is that they never are.

> Having said that, I've been very pleased in recent times with the
> ability of my Google Pixel phone to have stacking inbuilt, and achieving
> results which exceed what my eyes can see. It works very well.

in other words, things aren't equal.

computational photography can compensate for the drawbacks of smaller
sensors and in many cases, can exceed what a larger sensor could have
done.

> Since
> having a decent phone I've done much more photography.

everyone has.

On 2021-05-16 09:07, David Taylor wrote:
>
> Although likely beyond the range of an answer for a "layman", as
> originally requested!

Laymen are not immune to understanding things. "John Doe" already knows
about infrared. So give someone more food for thought and he has more
to go on in learning more.

--
"...there are many humorous things in this world; among them the white
man's notion that he is less savage than the other savages."
-Samuel Clemens

On 2021-05-15, John Doe <always.look@message.header> wrote:
> I'm a layman wondering if (generally speaking) increasing the ISO setting
> increases sensitivity to infrared light.

As others have pointed out, the sensitivity doesn't increase but rather the
gain. Digital cameras tend to have an IR filter to block IR. If yours has
been IR converted (the filter removed, in other words) then changing the ISO
will impact IR as well as visible light.

Incubus wrote:

> John Doe wrote:

>> I'm a layman wondering if (generally speaking) increasing the ISO setting
>> increases sensitivity to infrared light.
>
> As others have pointed out, the sensitivity doesn't increase but rather the
> gain. Digital cameras tend to have an IR filter to block IR. If yours has
> been IR converted (the filter removed, in other words) then changing the ISO
> will impact IR as well as visible light.

I'm satisfied.

Thanks to the replies.

On Saturday, 15 May 2021 at 17:45:19 UTC-4, Alan Browne wrote:
> On 2021-05-14 23:48, John Doe wrote:
> > I'm a layman wondering if (generally speaking) increasing the ISO setting
> > increases sensitivity to infrared light.
> Yes of course it does - at least to near infrared and possibly further.
> But most cameras have an IR filter over the sensor blocking those
> wavelengths.
but if you remove it, your exposure drops by about 1 stop when the IR light is added.

On Tuesday, 18 May 2021 at 03:17:55 UTC+1, RichA wrote:
> On Saturday, 15 May 2021 at 17:45:19 UTC-4, Alan Browne wrote:
> > On 2021-05-14 23:48, John Doe wrote:
> > > I'm a layman wondering if (generally speaking) increasing the ISO setting
> > > increases sensitivity to infrared light.
> > Yes of course it does - at least to near infrared and possibly further.
> > But most cameras have an IR filter over the sensor blocking those
> > wavelengths.

> but if you remove it, your exposure drops by about 1 stop when the IR light is added.

As I bought a canon EOS M with IR filter removed and it's classed as a full spectrum

So does the IR filter also just happen to filter out UV or it that separate and can be left in place.
So 2 filters ?

In article <6139ab11-4d2a-4815-b6c0-ba391e3d0edcn@googlegroups.com>,
Whisky-dave <whisky.dave@gmail.com> wrote:

>
> As I bought a canon EOS M with IR filter removed and it's classed as a full
> spectrum
>
> So does the IR filter also just happen to filter out UV or it that separate
> and can be left in place.
> So 2 filters ?

glass blocks uv.

there are special quartz lenses for uv photography.

On Tuesday, 18 May 2021 at 13:17:26 UTC+1, nospam wrote:
> In article <6139ab11-4d2a-4815...@googlegroups.com>,
> Whisky-dave <whisk...@gmail.com> wrote:
>
> >
> > As I bought a canon EOS M with IR filter removed and it's classed as a full
> > spectrum
> >
> > So does the IR filter also just happen to filter out UV or it that separate
> > and can be left in place.
> > So 2 filters ?
> glass blocks uv.
>
> there are special quartz lenses for uv photography.
No intention of doing UV work but the camera is decribed as full spectrumm
so must have had a UV blocking at some point.

https://www.infraredcameraconversions.co.uk/shop/4593495986/full-spectrum-canon-eos-m-black-body-only-or-kit---uv-visible-or-ir-converted-camera/11065543

In article <f0df942a-fa3b-4131-86a7-19f49143d874n@googlegroups.com>,
Whisky-dave <whisky.dave@gmail.com> wrote:

> > > As I bought a canon EOS M with IR filter removed and it's classed as a
> > > full
> > > spectrum
> > >
> > > So does the IR filter also just happen to filter out UV or it that
> > > separate
> > > and can be left in place.
> > > So 2 filters ?
> > glass blocks uv.
> >
> > there are special quartz lenses for uv photography.
> No intention of doing UV work but the camera is decribed as full spectrumm
> so must have had a UV blocking at some point.

glass.

On 2021-05-18, Whisky-dave <whisky.dave@gmail.com> wrote:
> On Tuesday, 18 May 2021 at 03:17:55 UTC+1, RichA wrote:
>> On Saturday, 15 May 2021 at 17:45:19 UTC-4, Alan Browne wrote:
>> > On 2021-05-14 23:48, John Doe wrote:
>> > > I'm a layman wondering if (generally speaking) increasing the ISO setting
>> > > increases sensitivity to infrared light.
>> > Yes of course it does - at least to near infrared and possibly further.
>> > But most cameras have an IR filter over the sensor blocking those
>> > wavelengths.
>
>> but if you remove it, your exposure drops by about 1 stop when the IR light is added.
>
> As I bought a canon EOS M with IR filter removed and it's classed as a full spectrum
>
> So does the IR filter also just happen to filter out UV or it that separate and can be left in place.
> So 2 filters ?

An IR filter only filters IR. It's the opposite side of the spectrum to UV.
Lenses often block a lot of UV themselves.

On Tuesday, 18 May 2021 at 14:43:46 UTC+1, Incubus wrote:
> On 2021-05-18, Whisky-dave <whisk...@gmail.com> wrote:
> > On Tuesday, 18 May 2021 at 03:17:55 UTC+1, RichA wrote:
> >> On Saturday, 15 May 2021 at 17:45:19 UTC-4, Alan Browne wrote:
> >> > On 2021-05-14 23:48, John Doe wrote:
> >> > > I'm a layman wondering if (generally speaking) increasing the ISO setting
> >> > > increases sensitivity to infrared light.
> >> > Yes of course it does - at least to near infrared and possibly further.
> >> > But most cameras have an IR filter over the sensor blocking those
> >> > wavelengths.
> >
> >> but if you remove it, your exposure drops by about 1 stop when the IR light is added.
> >
> > As I bought a canon EOS M with IR filter removed and it's classed as a full spectrum
> >
> > So does the IR filter also just happen to filter out UV or it that separate and can be left in place.
> > So 2 filters ?
> An IR filter only filters IR. It's the opposite side of the spectrum to UV.
> Lenses often block a lot of UV themselves.

Yes I know and you can get UV & IR filters too as I bought some that go on the front of the lens,
what I was wondering was whether my full spectrum camera
originally had two filters 1 UV and 1 IR on the sensor, I assumed so because you could get it non full spectrum.
i.e just IR. which I think is from ~540nm to 920nm but can;t quite remmber what the definition of full spectrum was when I
bought it.

In article <f32b51ef-e308-41d5-b2a4-7ecfb0f2ac0an@googlegroups.com>,
Whisky-dave <whisky.dave@gmail.com> wrote:

>
> Yes I know and you can get UV & IR filters too as I bought some that go on
> the front of the lens,

uv filters are a scam. they are extremely high profit margin items that
camera stores (when they existed) would push on uninformed customers.

the glass in the lens blocks uv. there is no need for an additional uv
filter.

those who want to protect the front element of the lens from dirt or
scratches can get a clear glass filter, but that will have a small
effect on image quality. stay away from the cheap shit, which has a
much bigger effect on image quality.

it's quite amusing when people will spend thousands of dollars on a
lens and then put a shitty $5 filter to protect it.

ir filters come in two variants, blocking and pass.

ir blocking filters, aka hot mirror, restore the ir blocking that is no
longer done on the sensor, making the camera 'normal' again.

ir pass filters block visible light for true ir photography, although
they are incompatible with slrs.

On 2021-05-18, nospam <nospam@nospam.invalid> wrote:
> In article <f32b51ef-e308-41d5-b2a4-7ecfb0f2ac0an@googlegroups.com>,
> Whisky-dave <whisky.dave@gmail.com> wrote:
>
>>
>> Yes I know and you can get UV & IR filters too as I bought some that go on
>> the front of the lens,
>
> uv filters are a scam. they are extremely high profit margin items that
> camera stores (when they existed) would push on uninformed customers.
>
> the glass in the lens blocks uv. there is no need for an additional uv
> filter.

I thought about 75% of UVA passes through glass. This was a problem with older
film but not really an issue for modern film or digital photography. UVB is
completely blocked.

> those who want to protect the front element of the lens from dirt or
> scratches can get a clear glass filter, but that will have a small
> effect on image quality. stay away from the cheap shit, which has a
> much bigger effect on image quality.
>
> it's quite amusing when people will spend thousands of dollars on a
> lens and then put a shitty $5 filter to protect it.
>
> ir filters come in two variants, blocking and pass.
>
> ir blocking filters, aka hot mirror, restore the ir blocking that is no
> longer done on the sensor, making the camera 'normal' again.
>
> ir pass filters block visible light for true ir photography, although
> they are incompatible with slrs.

I understand the practice with SLRs (D or otherwise) is to frame the shot, take a
light reading and then attach the filter and increase the shutter speed by a
set number of stops.

On Tuesday, 18 May 2021 at 09:43:46 UTC-4, Incubus wrote:
> On 2021-05-18, Whisky-dave <whisk...@gmail.com> wrote:
> > On Tuesday, 18 May 2021 at 03:17:55 UTC+1, RichA wrote:
> >> On Saturday, 15 May 2021 at 17:45:19 UTC-4, Alan Browne wrote:
> >> > On 2021-05-14 23:48, John Doe wrote:
> >> > > I'm a layman wondering if (generally speaking) increasing the ISO setting
> >> > > increases sensitivity to infrared light.
> >> > Yes of course it does - at least to near infrared and possibly further.
> >> > But most cameras have an IR filter over the sensor blocking those
> >> > wavelengths.
> >
> >> but if you remove it, your exposure drops by about 1 stop when the IR light is added.
> >
> > As I bought a canon EOS M with IR filter removed and it's classed as a full spectrum
> >
> > So does the IR filter also just happen to filter out UV or it that separate and can be left in place.
> > So 2 filters ?
> An IR filter only filters IR. It's the opposite side of the spectrum to UV.
> Lenses often block a lot of UV themselves.

Unless comprised of quartz and/or fluorite.

On Tuesday, 18 May 2021 at 15:56:31 UTC+1, nospam wrote:
> In article <f32b51ef-e308-41d5...@googlegroups.com>,
> Whisky-dave <whisk...@gmail.com> wrote:
>
> >
> > Yes I know and you can get UV & IR filters too as I bought some that go on
> > the front of the lens,
> uv filters are a scam. they are extremely high profit margin items that
> camera stores (when they existed) would push on uninformed customers.

Not if you bought them to protect the lens.
There were also skylight1A & 1B also pretty unnecessary as less you bought them primary to
protect the lens, a bit like a transparent lens cap.
Otherwose you could claim less caps are a waste of time too.

>
> the glass in the lens blocks uv. there is no need for an additional uv
> filter.

So how to full spectrum cameras record UV ?

>
> those who want to protect the front element of the lens from dirt or
> scratches can get a clear glass filter, but that will have a small
> effect on image quality. stay away from the cheap shit, which has a
> much bigger effect on image quality.

Not seen any clear glass filters, unless you mean Zero ND.

>
> it's quite amusing when people will spend thousands of dollars on a
> lens and then put a shitty $5 filter to protect it.

Well, in the UK the filters suggested are usualy quite expensive as are adition lens caps
for the more expensive lenes the more expensive the accessories.

>
> ir filters come in two variants, blocking and pass.

Yes I know but filters tend to block some type of light and pass others anyway.
It;s the wavelenght of light that is important .

>
> ir blocking filters, aka hot mirror, restore the ir blocking that is no
> longer done on the sensor, making the camera 'normal' again.
>
> ir pass filters block visible light for true ir photography, although
> they are incompatible with slrs.

why are they incompatable with slrs ?
and there's no such thing as true IR light is a wavelengh not a band as such.

On Tuesday, 18 May 2021 at 17:58:27 UTC+1, Incubus wrote:
> On 2021-05-18, nospam <nos...@nospam.invalid> wrote:
> > In article <f32b51ef-e308-41d5...@googlegroups.com>,
> > Whisky-dave <whisk...@gmail.com> wrote:
> >
> >>
> >> Yes I know and you can get UV & IR filters too as I bought some that go on
> >> the front of the lens,
> >
> > uv filters are a scam. they are extremely high profit margin items that
> > camera stores (when they existed) would push on uninformed customers.
> >
> > the glass in the lens blocks uv. there is no need for an additional uv
> > filter.
> I thought about 75% of UVA passes through glass. This was a problem with older
> film but not really an issue for modern film or digital photography. UVB is
> completely blocked.
> > those who want to protect the front element of the lens from dirt or
> > scratches can get a clear glass filter, but that will have a small
> > effect on image quality. stay away from the cheap shit, which has a
> > much bigger effect on image quality.
> >
> > it's quite amusing when people will spend thousands of dollars on a
> > lens and then put a shitty $5 filter to protect it.
> >
> > ir filters come in two variants, blocking and pass.
> >
> > ir blocking filters, aka hot mirror, restore the ir blocking that is no
> > longer done on the sensor, making the camera 'normal' again.
> >
> > ir pass filters block visible light for true ir photography, although
> > they are incompatible with slrs.
> I understand the practice with SLRs (D or otherwise) is to frame the shot, take a
> light reading and then attach the filter and increase the shutter speed by a
> set number of stops.

if you know what you are doing you can use the+/- compensation dial that most camers have.

In article <84df94f9-84f8-4f1c-8988-0e23bad77584n@googlegroups.com>,
Whisky-dave <whisky.dave@gmail.com> wrote:

> > > Yes I know and you can get UV & IR filters too as I bought some that go
> > > on
> > > the front of the lens,
> > uv filters are a scam. they are extremely high profit margin items that
> > camera stores (when they existed) would push on uninformed customers.
>
> Not if you bought them to protect the lens.

that's what a lens cap is for, and it even comes with the lens. no need
to buy anything extra.

in the event you need a replacement, they're cheap.

> There were also skylight1A & 1B also pretty unnecessary as less you bought
> them primary to
> protect the lens, a bit like a transparent lens cap.
> Otherwose you could claim less caps are a waste of time too.

skylight filters were a bigger waste of money.

> > the glass in the lens blocks uv. there is no need for an additional uv
> > filter.
>
> So how to full spectrum cameras record UV ?

with quartz lenses.

> > those who want to protect the front element of the lens from dirt or
> > scratches can get a clear glass filter, but that will have a small
> > effect on image quality. stay away from the cheap shit, which has a
> > much bigger effect on image quality.
>
> Not seen any clear glass filters, unless you mean Zero ND.

they are widely available, in varying levels of quality.

> > it's quite amusing when people will spend thousands of dollars on a
> > lens and then put a shitty $5 filter to protect it.
>
> Well, in the UK the filters suggested are usualy quite expensive as are
> adition lens caps
> for the more expensive lenes the more expensive the accessories.

of course what they suggest is expensive. more profit for the store.

> > ir filters come in two variants, blocking and pass.
>
> Yes I know but filters tend to block some type of light and pass others
> anyway.
> It;s the wavelenght of light that is important .

whoosh.

> > ir blocking filters, aka hot mirror, restore the ir blocking that is no
> > longer done on the sensor, making the camera 'normal' again.
> >
> > ir pass filters block visible light for true ir photography, although
> > they are incompatible with slrs.
>
> why are they incompatable with slrs ?

with an slr, you are looking through the lens, so if you attach a
filter to the lens that blocks all visible light, then you won't be
seeing anything unless you are an alien life form that can see
infrared.

> and there's no such thing as true IR light is a wavelengh not a band as such.

false.

On 2021-05-21, Whisky-dave <whisky.dave@gmail.com> wrote:
> On Tuesday, 18 May 2021 at 17:58:27 UTC+1, Incubus wrote:
>> On 2021-05-18, nospam <nos...@nospam.invalid> wrote:
>> > In article <f32b51ef-e308-41d5...@googlegroups.com>,
>> > Whisky-dave <whisk...@gmail.com> wrote:
>> >
>> >>
>> >> Yes I know and you can get UV & IR filters too as I bought some that go on
>> >> the front of the lens,
>> >
>> > uv filters are a scam. they are extremely high profit margin items that
>> > camera stores (when they existed) would push on uninformed customers.
>> >
>> > the glass in the lens blocks uv. there is no need for an additional uv
>> > filter.
>> I thought about 75% of UVA passes through glass. This was a problem with older
>> film but not really an issue for modern film or digital photography. UVB is
>> completely blocked.
>> > those who want to protect the front element of the lens from dirt or
>> > scratches can get a clear glass filter, but that will have a small
>> > effect on image quality. stay away from the cheap shit, which has a
>> > much bigger effect on image quality.
>> >
>> > it's quite amusing when people will spend thousands of dollars on a
>> > lens and then put a shitty $5 filter to protect it.
>> >
>> > ir filters come in two variants, blocking and pass.
>> >
>> > ir blocking filters, aka hot mirror, restore the ir blocking that is no
>> > longer done on the sensor, making the camera 'normal' again.
>> >
>> > ir pass filters block visible light for true ir photography, although
>> > they are incompatible with slrs.
>> I understand the practice with SLRs (D or otherwise) is to frame the shot, take a
>> light reading and then attach the filter and increase the shutter speed by a
>> set number of stops.
>
> if you know what you are doing you can use the+/- compensation dial that most camers have.

Exposure compensation is often +/- three stops. From memory, you need to
increase your expsosure by at least four for IR. You have to do it manually
anyway; with a filter attached, don't expect the light meter to function as
intended.