Higher ISO more sensitive to infrared light?

In article ,
Whisky-dave 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.

In article ,
Whisky-dave 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.

In article ,
Whisky-dave 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 ****, 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 ****ty $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.

In article ,
Whisky-dave 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 ****, 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 ****ty $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.

In article , Incubus
wrote:

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.

the meters are calibrated for visible light.

what they do with infrared will vary, depending on the camera. same for
flashes.