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More on Canon Rebel XT noise at high ISO - 2 main new data points



 
 
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  #1  
Old December 30th 05, 10:29 PM posted to rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default More on Canon Rebel XT noise at high ISO - 2 main new data points

I went to another camera store earlier this afternoon mainly
to look at the Canon 430 external flash, which I did buy.

While I was there, I talked to the manager, whom I know well
and trust, about the (apparent) noise I'm seeing with my XT.
Like most everyone else, he was incredulous, then strongly
suggested that my particular camera was defective, as his
experience was 100% the opposite.

Since I had my camera around my neck, I asked if I could try
one of his, that he knew to be working correctly. "Sure, have
at it!". So, I pumped off about 30 shots, some with the built-
in Speedlite and some available light, across subjects with a
lot of detail and both light and dark backgrounds (the latter
to better pick up any inherent noise).

When I got home, I took another series of pictures with my own
camera, then loaded the whole mess onto all 3 of my PCs. One
of my PCs is quite old, still running Win 98, with a 17" CRT
with brightness and contrast cranked down because my wife says
the glare hurts her eyes. The 2nd one is my old Win XP SP1
machine, also with a 17" CRT that I know is showing images too
dark. Finally, I put them on my new Win XP SP2 box with a 21"
Samsung LCD which I know is properly calibrated for both
brightness/contrast and RGB. Please don't go off on the
monitors, just yet, OK?

By this time of day (4:15PM EST), my fav store manager had
left for the holiday weekend, so I'll talk to him on Monday.
But, the bottom line is this, 2-fold:

1) /Both/ camera's, my "defective" one and his "working" one
showed the /same/ amount of noise at /all/ ISO from 100 to
1600 on /all/ 3 of my PCs. Naturally, no noise is readily
apparent until ISO 400 on both cameras.

2) Despite being careful on Programmed Auto in both flash and
available light, some of the pics I took with the store's
camera and pics I took in my house with my own, are a stop or
2 underexposed. Please don't debate this yet, either. The more
the underexposure, the higher the noise. Well, Duh?! I already
knew that, and that explains the extra noise I got Wednesday
at the WPC Museum - but which I've already explained I
understand.

I /will/ investigate this further, you can trust. But, so far,
it still looks like the medium 5.5 MP images saved on both
cameras with the highest quality (least JPEG compression)
/all/ show about the same amount of noise.

As I do not understand RAW, and do not have Canon's RAW
converter on my PC to avoid invalidating the store's return
policy, I cannot evaluate that. Suffice to say that there /is/
a problem with the Rebel XT - from my perspective.

Now, you can all write me off as just another
nutbag/troll/incompetant/inexperienced/closed minded/asshole
if you like. But, as the saying goes "I don't know anything
about art, but I know what I like." And, I recognize noise
when I see it, as well as I understand what makes it worse.

Calm, rationale, non-insulting comments are welcomed. Insults
to me or my intelligence will be ignored. And, please
everyone, have a very Happy New Year!

--
ATM, aka Jerry

"I disagree with what you say, but I will defend to the death
your right to say it." - Evelyn Beatrice Hall under the
pseudonym Stephen G. Tallentyre
  #2  
Old December 30th 05, 10:49 PM posted to rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default More on Canon Rebel XT noise at high ISO - 2 main new data points


"All Things Mopar" wrote in message
...
I went to another camera store earlier this afternoon mainly
to look at the Canon 430 external flash, which I did buy.

While I was there, I talked to the manager, whom I know well
and trust, about the (apparent) noise I'm seeing with my XT.
Like most everyone else, he was incredulous, then strongly
suggested that my particular camera was defective, as his
experience was 100% the opposite.

Since I had my camera around my neck, I asked if I could try
one of his, that he knew to be working correctly. "Sure, have
at it!". So, I pumped off about 30 shots, some with the built-
in Speedlite


There is no such thing as a built-in Speedlite. It's a frickin' pop-up
flash. The Canon external flash units are Speedlites.

When I got home, I took another series of pictures with my own
camera, then loaded the whole mess onto all 3 of my PCs. One
of my PCs is quite old, still running Win 98, with a 17" CRT
with brightness and contrast cranked down because my wife says
the glare hurts her eyes. The 2nd one is my old Win XP SP1
machine, also with a 17" CRT that I know is showing images too
dark. Finally, I put them on my new Win XP SP2 box with a 21"
Samsung LCD which I know is properly calibrated for both
brightness/contrast and RGB. Please don't go off on the
monitors, just yet, OK?

By this time of day (4:15PM EST), my fav store manager had
left for the holiday weekend, so I'll talk to him on Monday.
But, the bottom line is this, 2-fold:

1) /Both/ camera's, my "defective" one and his "working" one
showed the /same/ amount of noise at /all/ ISO from 100 to
1600 on /all/ 3 of my PCs. Naturally, no noise is readily
apparent until ISO 400 on both cameras.

2) Despite being careful on Programmed Auto in both flash and
available light, some of the pics I took with the store's
camera and pics I took in my house with my own, are a stop or
2 underexposed.


Known issue on Digital Rebel and Rebel XTs. Use + EC.


Now, you can all write me off as just another
nutbag/troll/incompetant/inexperienced/closed minded/asshole
if you like.


Yes, most here have.

Greg


  #3  
Old December 30th 05, 11:03 PM posted to rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default More on Canon Rebel XT noise at high ISO - 2 main new data points

Today G.T. commented courteously on the subject at hand

There is no such thing as a built-in Speedlite. It's a
frickin' pop-up flash. The Canon external flash units are
Speedlites.


I thought that's what the manual calls it. But, a better
question is, why the hell do you care, other than to make an
ass of yourself taking me on - again?

When I got home, I took another series of pictures with my
own camera, then loaded the whole mess onto all 3 of my
PCs. One of my PCs is quite old, still running Win 98,
with a 17" CRT with brightness and contrast cranked down
because my wife says the glare hurts her eyes. The 2nd one
is my old Win XP SP1 machine, also with a 17" CRT that I
know is showing images too dark. Finally, I put them on my
new Win XP SP2 box with a 21" Samsung LCD which I know is
properly calibrated for both brightness/contrast and RGB.
Please don't go off on the monitors, just yet, OK?

By this time of day (4:15PM EST), my fav store manager had
left for the holiday weekend, so I'll talk to him on
Monday. But, the bottom line is this, 2-fold:

1) /Both/ camera's, my "defective" one and his "working"
one showed the /same/ amount of noise at /all/ ISO from
100 to 1600 on /all/ 3 of my PCs. Naturally, no noise is
readily apparent until ISO 400 on both cameras.

2) Despite being careful on Programmed Auto in both flash
and available light, some of the pics I took with the
store's camera and pics I took in my house with my own,
are a stop or 2 underexposed.


Known issue on Digital Rebel and Rebel XTs. Use + EC.


What means "+ EC"? Don't know it, didn't get anything
Googling, can't find it in the manual (unless I've blind). I
know what EV is...

Now, you can all write me off as just another
nutbag/troll/incompetant/inexperienced/closed
minded/asshole if you like.


Yes, most here have.

Okey, Dokey by me. You don't mind if I think the same of you,
do you? Such as your smart ass crack at the top?

--
ATM, aka Jerry

"I disagree with what you say, but I will defend to the death
your right to say it." - Evelyn Beatrice Hall under the
pseudonym Stephen G. Tallentyre
  #4  
Old December 30th 05, 11:17 PM posted to rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default More on Canon Rebel XT noise at high ISO - 2 main new data points


"All Things Mopar" wrote in message
...

2) Despite being careful on Programmed Auto in both flash
and available light, some of the pics I took with the
store's camera and pics I took in my house with my own,
are a stop or 2 underexposed.


Known issue on Digital Rebel and Rebel XTs. Use + EC.


What means "+ EC"? Don't know it, didn't get anything
Googling, can't find it in the manual (unless I've blind). I
know what EV is...


Exposure compensation. I'm a relative newbie to photography and since
you're an experienced photographer I thought you would know what EC is. It
sounds like most of your noise trouble is due to underexposure.

Greg


  #5  
Old December 30th 05, 11:46 PM posted to rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default More on Canon Rebel XT noise at high ISO - 2 main new data points

Today G.T. commented courteously on the subject at hand

Exposure compensation. I'm a relative newbie to
photography and since you're an experienced photographer I
thought you would know what EC is. It sounds like most of
your noise trouble is due to underexposure.

Thank you, Greg. Now please re-reread the relevant portions of
my posts. I have said, repeatedly, that I understand why
underexposure exacerabates any inherent noise. Now, will you
acknowledge that underexposure is /not/ the only cause of noise,
particularly when I'm talking about only 1-2 f/stops? Yes, thank
you.

Since I know that you parlez vous EXIF, all you want to know is
in my example posts, if you can get to them. Or, I would be
happy to E-mail them. But, that's old news right now, since I
got a significant 2nd data point trying the other store's
"good" camera.

--
ATM, aka Jerry

"I disagree with what you say, but I will defend to the death
your right to say it." - Evelyn Beatrice Hall under the
pseudonym Stephen G. Tallentyre
  #6  
Old December 31st 05, 01:06 AM posted to rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default More on Canon Rebel XT noise at high ISO - 2 main new data points

For the sake of completeness, mainly that someone else may stumble on
this thread looking for useful information...

While I was there, I talked to the manager, whom I know well
and trust, about the (apparent) noise I'm seeing with my XT.
Like most everyone else, he was incredulous, then strongly
suggested that my particular camera was defective, as his
experience was 100% the opposite.


Given that later he establishes that the store-owner's 100% good camera
and his 'bad' one behave identically, what would a normal person infer?

So, I pumped off about 30 shots, some with the built-
in Speedlite and some available light, across subjects with a
lot of detail and both light and dark backgrounds (the latter
to better pick up any inherent noise).


In other words he went looking for noise in dark areas...

1) /Both/ camera's, my "defective" one and his "working" one
showed the /same/ amount of noise at /all/ ISO from 100 to
1600 on /all/ 3 of my PCs. Naturally, no noise is readily
apparent until ISO 400 on both cameras.


Good-oh. No real surprises there.

2) Despite being careful on Programmed Auto in both flash


Oh dear. Here we go back to square one. I've never yet met a
camera/flashgun combo that had infallible auto-exposure. In
particular, and as stated MANY times, if the subject has significant
refelective areas that bounce the flash back at the sensor/s.. You
can't be 'careful' in auto mode. Manual mode, or proper flash
metering, is being careful.

some of the pics I took with the store's
camera and pics I took in my house with my own, are a stop or
2 underexposed. Please don't debate this yet, either.


When should we? It's directly relevant. Even at a single stop
underexposure, noise problems will be exaggerated, and at 400 ISO will
be by far the most significant cause. And on auto mode, he is asking
for wrongly exposed images, especially if there is anything even
remotely challenging in the subject. Like.. chrome and polished
paintwork.

The more the underexposure, the higher the noise.
Well, Duh?! I already knew that, and that explains the
extra noise I got Wednesday at the WPC Museum
- but which I've already explained I understand.


And we do too.

so far, it still looks like the medium 5.5 MP images
saved on both cameras with the highest quality
(least JPEG compression) /all/ show about the same
amount of noise.


Fine. Point being? And why not at least use Tiff files if evaluating
noise.

Suffice to say that there /is/
a problem with the Rebel XT - from my perspective.


Key words - 'from my perspective'.

Another way of saying all this is - 'I'm not prepared to put in the
effort to ensure my images are correctly exposed, even though I shoot
shiny objects in dim environments, namely cars with an on-camera flash
(yes, I'm *serious*). My images come out underexposed and noisy. It's
the equipment's fault. I can't believe that all my cameras and flashes
have this problem to a greater or lesser extent, and that no-one here
will help me. It's certainly not my technique, and don't you *dare*
suggest I'm trying to do something the wrong way. Agree with me and
I'll be your friend. Suggest anything else and get in the neck.'

Now, you can all write me off as just another
nutbag/troll/incompetant/inexperienced/closed minded/asshole
if you like.


Heavens no. Not us. Uh-uh. No way.

But, as the saying goes "I don't know anything
about art, but I know what I like."


The people who say that are BUYING the art, not creating it. I think
he missed the point of the metaphor entirely. (O: (O: (O:

Insults to me or my intelligence will be ignored.


I betcha he doesn't.....

  #7  
Old December 31st 05, 07:25 AM posted to rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default More on Canon Rebel XT noise at high ISO - 2 main new data points

Today Chrlz commented courteously on the subject at hand

[snip the babble]
Fine. Point being? And why not at least use Tiff files if
evaluating noise.


'Cuz the XT doesn't save to TIFF, just JPEG & RAW? 'Course you
knew that, right?

[snip more babble]

--
ATM, aka Jerry

"I disagree with what you say, but I will defend to the death
your right to say it." - Evelyn Beatrice Hall under the
pseudonym Stephen G. Tallentyre
  #8  
Old December 31st 05, 07:25 AM posted to rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default More on Canon Rebel XT noise at high ISO - 2 main new data points

Today Chrlz commented courteously on the subject at hand

For the sake of completeness, mainly that someone else may
stumble on this thread looking for useful information...

While I was there, I talked to the manager, whom I know
well and trust, about the (apparent) noise I'm seeing with
my XT. Like most everyone else, he was incredulous, then
strongly suggested that my particular camera was defective,
as his experience was 100% the opposite.


Given that later he establishes that the store-owner's 100%
good camera and his 'bad' one behave identically, what
would a normal person infer?

So, I pumped off about 30 shots, some with the built-
in Speedlite and some available light, across subjects with
a lot of detail and both light and dark backgrounds (the
latter to better pick up any inherent noise).


In other words he went looking for noise in dark areas...

1) /Both/ camera's, my "defective" one and his "working"
one showed the /same/ amount of noise at /all/ ISO from 100
to 1600 on /all/ 3 of my PCs. Naturally, no noise is
readily apparent until ISO 400 on both cameras.


Good-oh. No real surprises there.

2) Despite being careful on Programmed Auto in both flash


Oh dear. Here we go back to square one. I've never yet
met a camera/flashgun combo that had infallible
auto-exposure. In particular, and as stated MANY times, if
the subject has significant refelective areas that bounce
the flash back at the sensor/s.. You can't be 'careful' in
auto mode. Manual mode, or proper flash metering, is being
careful.

some of the pics I took with the store's
camera and pics I took in my house with my own, are a stop
or 2 underexposed. Please don't debate this yet, either.


When should we? It's directly relevant. Even at a single
stop underexposure, noise problems will be exaggerated, and
at 400 ISO will be by far the most significant cause. And
on auto mode, he is asking for wrongly exposed images,
especially if there is anything even remotely challenging
in the subject. Like.. chrome and polished paintwork.

The more the underexposure, the higher the noise.
Well, Duh?! I already knew that, and that explains the
extra noise I got Wednesday at the WPC Museum - but which
I've already explained I understand.


And we do too.

so far, it still looks like the medium 5.5 MP images
saved on both cameras with the highest quality
(least JPEG compression) /all/ show about the same amount
of noise.


Fine. Point being? And why not at least use Tiff files if
evaluating noise.

Suffice to say that there /is/ a problem with the Rebel XT
- from my perspective.


Key words - 'from my perspective'.

Another way of saying all this is - 'I'm not prepared to
put in the effort to ensure my images are correctly
exposed, even though I shoot shiny objects in dim
environments, namely cars with an on-camera flash (yes, I'm
*serious*). My images come out underexposed and noisy.
It's the equipment's fault. I can't believe that all my
cameras and flashes have this problem to a greater or
lesser extent, and that no-one here will help me. It's
certainly not my technique, and don't you *dare* suggest
I'm trying to do something the wrong way. Agree with me
and I'll be your friend. Suggest anything else and get in
the neck.'

Now, you can all write me off as just another
nutbag/troll/incompetant/inexperienced/closed
minded/asshole if you like.


Heavens no. Not us. Uh-uh. No way.

But, as the saying goes "I don't know anything about art,
but I know what I like."


The people who say that are BUYING the art, not creating
it. I think he missed the point of the metaphor entirely.
(O: (O: (O:

Insults to me or my intelligence will be ignored.


I betcha he doesn't.....


--
ATM, aka Jerry

"I disagree with what you say, but I will defend to the death
your right to say it." - Evelyn Beatrice Hall under the
pseudonym Stephen G. Tallentyre
  #9  
Old December 31st 05, 07:44 AM posted to rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default More on Canon Rebel XT noise at high ISO - 2 main new data points

'Cuz the XT doesn't save to TIFF, just JPEG & RAW?
I'm very surprised to hear that. I personally would never evaluate a
camera on JPG's alone, especially if it was about noise issues. That
would surely be a reason to borrow the owner's software temporarily.

'Course you knew that, right?

No I didn't. So I unreservedly apologise for my error/assumption and
thank you for the correction.



See how easy it is to be civil?

  #10  
Old December 31st 05, 08:41 AM posted to rec.photo.digital.slr-systems
external usenet poster
 
Posts: n/a
Default More on Canon Rebel XT noise at high ISO - 2 main new data points

Today Chrlz commented courteously on the subject at hand

'Cuz the XT doesn't save to TIFF, just JPEG & RAW?


I'm very surprised to hear that. I personally would never
evaluate a camera on JPG's alone, especially if it was
about noise issues. That would surely be a reason to
borrow the owner's software temporarily.


Well, being the dummy that I am, I never shoot in anything but
JPEG and always have. And, I never save anything in JPEG and
always have. For my purposes as a documentary photographer of
cars, that has worked admirably for me through film and 3
digitals.

So, while I wanted RAW for later once I figure out how to use
it, and new the XT has it, I wasn't at all interested in TIFF.
At least one reason is that the files cannot be compressed if
EXIF is desired, which makes them way bigger than they are
worth.

If you want to evaluate noise in the lab or using some
mathematical routine in your fav graphics editor, you may be
right about TIFF vs. JPEG. But, as the old saying goes "I
don't know anything about art, but I know what I like" -
meaning, I can recognize noise when I see it, no matter what
format the picture is saved in.

'Course you knew that, right?


No I didn't. So I unreservedly apologise for my
error/assumption and thank you for the correction.


You and I will get along better, Chris, as well and me and
everyone else here, if we start off with the assumption that
the other guy isn't a dummy, ask reasonable, polite, and
intelligent questions, and wait patiently for an answer.

Frankly, I was quite suprised not to find TIFF. And, I was
also surprised not to find any 4:3 sizes. But, I've already
figured that out. I just zoom out/stand farther back about 20-
25% and use a PSP 9 crop preset on the 5.5 MP images I shoot.
That way, I am assured of not chopping anything off my main
subject and I have plenty of pixels to crop without reducing
the resolution I want. Problem solved.

See how easy it is to be civil?

Yes. And, I would have apologized by now to those that I
offended if I'd have been treated even moderately well here.
But, what happened yesterday is things went very rapidly
downhill, so I had little incentive to be civil.

--
ATM, aka Jerry

"I disagree with what you say, but I will defend to the death
your right to say it." - Evelyn Beatrice Hall under the
pseudonym Stephen G. Tallentyre
 




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