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View Full Version : All this NOISE, NOISE, NOISE!!!!!


Itchy
10-09-2010, 07:38 PM
Pictures the Grinch looking at some pictures he just took ..... with all the Camera talk going around I would like to show how a storm with grey scale and low light can create a lot of noise in a Rebel Xsi.......

This is a picture after being sharpened and post picture noise reduction and sharpening with the Canon software.
This was at 400 Iso..... before the noise reduction there was even a few hot pixels causing a couple red dots.

This was AFTER applying noise reduction and sharpening and still look at the noise, so imagine the raw image
What happened is I was shooting at 400 earlier in the chase in bright light and forgot to change it back down to 100..... These images would have looks so much nicer at iso 100, but you would need the steady hand for the longer exposure

Again it may not look like a lot of noise but I have used reduction software and this is what remains so again imagine the originals

http://farm4.static.flickr.com/3595/3577124731_0f12a1b09c_b.jpg

http://farm3.static.flickr.com/2444/3577921398_8d8e63341d_b.jpg

Now a low light shot at 100 Iso no noise reduction applied after the Image.
Much crisper than the above shots because noise reduction software from Canon takes away the sharpness.....
The image below here was a much darker situation than above and more taxing on the camera if iso was at 400 it would have been Incredibly grainy.......

http://farm4.static.flickr.com/3047/3815976086_f3a083c18d_b.jpg

I hope this helps put into perspective the ability of a rebel Xsi without any fancy cs4 effects and the stock lens. I don't mean to sound like I'm bashing the cam just trying to sound unbiased. It was a great camera for the time I bought it and a great starter SLR

davefootball123
10-09-2010, 09:31 PM
That noise isnt that bad although at 400 iso it could be better :p

gecko
10-10-2010, 01:06 AM
Sharpening can aggravate or introduce noise, depending how it's applied and what sort of source material you're dealing with. Previewing sharpening at 100 percent magnification will help you see if it's contributing to the problem.

DarkSky
10-10-2010, 10:14 AM
Any time in low light you're going to get more noticeable noise too. There's just not enough light hitting those pixels for the sensor to get a good determination of what colour to show. If you're using a tripod you can always set the ISO and aperature down lower to allow the sensor more time to pick up the proper definition.

Maybe do a web search for iso comparisons and see what other cameras are like at certain ISO speeds compared to yours, in low light.

About a third of the way down on this page you can see your camera compared to others:

http://www.the-digital-picture.com/Reviews/Canon-EOS-Rebel-XSi-450D-Digital-SLR-Camera-Review.aspx

Itchy
10-10-2010, 03:59 PM
Sharpening can aggravate or introduce noise, depending how it's applied and what sort of source material you're dealing with. Previewing sharpening at 100 percent magnification will help you see if it's contributing to the problem.

Almost every time I apply any sharpening that is the case, usually I can get away with adding no noticeable noise by not cranking it but just increasing it by a teeny bit over the original, if I sharpened fully the trees looks really weird as well as the added noise.

Itchy
10-10-2010, 04:03 PM
Any time in low light you're going to get more noticeable noise too. There's just not enough light hitting those pixels for the sensor to get a good determination of what colour to show. If you're using a tripod you can always set the ISO and aperature down lower to allow the sensor more time to pick up the proper definition.

Maybe do a web search for iso comparisons and see what other cameras are like at certain ISO speeds compared to yours, in low light.

About a third of the way down on this page you can see your camera compared to others:

http://www.the-digital-picture.com/Reviews/Canon-EOS-Rebel-XSi-450D-Digital-SLR-Camera-Review.aspx


You are totally right about aperture down, that is a technique I picked up by trial and error and read about after..... I first noticed it on my small chase on august 20, 2009. I do it to the point were the image is slightly over exposed and then darken and increase the contrast with software, I find this to give excellent sharpness and colour in the clouds while keeping noise as low as possible compared to a plain unprocessed raw

Although I don't like how blurry the foreground can get in some shots when I have to do that

DarkSky
10-10-2010, 07:13 PM
You are totally right about aperture down, that is a technique I picked up by trial and error and read about after..... I first noticed it on my small chase on august 20, 2009. I do it to the point were the image is slightly over exposed and then darken and increase the contrast with software, I find this to give excellent sharpness and colour in the clouds while keeping noise as low as possible compared to a plain unprocessed raw

Although I don't like how blurry the foreground can get in some shots when I have to do that

Actually it should be the other way around. With a high aperature (low f-rating) you will get a shallow depth of field: your subject will be in focus but stuff in front of and behind the subject will blur out more. With a lower aperature (higher f-rating) you'll get a larger depth of field: it will tend to bring both the foreground and background more into focus.

Shallow depth of fields are great for people pictures as they bring the subject right to the center of attention in the photo. But for landscape portraits, I like to use a larger depth of field to make the picture look 'as big' as possible.

Itchy
10-10-2010, 08:35 PM
Actually it should be the other way around. With a high aperature (low f-rating) you will get a shallow depth of field: your subject will be in focus but stuff in front of and behind the subject will blur out more. With a lower aperature (higher f-rating) you'll get a larger depth of field: it will tend to bring both the foreground and background more into focus.

Shallow depth of fields are great for people pictures as they bring the subject right to the center of attention in the photo. But for landscape portraits, I like to use a larger depth of field to make the picture look 'as big' as possible.

HAHAHA see I always flip it around in my head and think high aperture high f rating , brain fart

DarkSky
10-11-2010, 12:22 AM
HAHAHA see I always flip it around in my head and think high aperture high f rating , brain fart

Yah I'm usually like that too but I made a mental note to get it right while typing that msg :D Had to proof read it before submitting to make sure it was correct.

Basically think of high aperature = high amount of light allowed in.

obwan
10-11-2010, 10:33 AM
Here is something to keep in mind when shooting with a dslr(slr). It is not always about the iso. And if you buy a slr with removeable lenses it is important to remember the aperture range is determined by the lens not the camera. Dave, that is why I said the 70-300 is not such a good lens because such a large depth range limits your aperture(light) range. Static depth range lenses can offer greater range of aperture.

here is some reading
http://www.photoxels.com/tutorial_aperture.html

davefootball123
10-11-2010, 11:21 AM
Obwan. I went to try out a couple of cameras yesterday at henrys. Ive come to conclusion that the d3100 over the T2i. It feels better in my hand and high iso preformance has a slight edge. My lenses will be the 18-55 F3.5-5.6 as my starter and then i will be getting a 55-300 tele nikon nikkor lense. For 429 thats not bad. then i was thinking. Get a macro or get a wide angle. Macro would be a nikkor 35mm 1.8 which is great in low light and then mabye something like a sigma 10-20mm or mabye a fisheye

DarkSky
10-12-2010, 01:32 PM
Here is something to keep in mind when shooting with a dslr(slr). It is not always about the iso. And if you buy a slr with removeable lenses it is important to remember the aperture range is determined by the lens not the camera. Dave, that is why I said the 70-300 is not such a good lens because such a large depth range limits your aperture(light) range. Static depth range lenses can offer greater range of aperture.

here is some reading
http://www.photoxels.com/tutorial_aperture.html

Yah an average non-pro 70-300mm lens you're looking at a BEST aperature (biggest) of f4 (@<hidden> 70mm). And of course, the more you telescope out the lens, the less light gets in, and f5.6 is average @<hidden> 300mm. But a cheap 75-300m is good for outdoor sports photography / wildlife photography, and when used with a tripod. But the lack of light getting in to it will require a longer exposure time...

Or you could get a nice fast f2.8 200mm lens. But that's why an f4-5.6 30-700mm lens costs $350, and an f2.8 70-200mm costs $2800 :D

obwan
10-12-2010, 06:10 PM
yes i worded my answer wrong in saying the 70-300 lens isn't such a good lens. it depends on what you're shooting, or which lens you can afford. all lenses are great if you can afford the quality ones.

DarkSky
10-12-2010, 09:54 PM
yes i worded my answer wrong in saying the 70-300 lens isn't such a good lens. it depends on what you're shooting, or which lens you can afford. all lenses are great if you can afford the quality ones.

Yep. My first telephoto was a 75-300 ($600 at the time I believe) about a decade ago. It was for my 35mm film SLR (Canon Rebel 2000). Then I got a DSLR (Canon Digital Rebel) which I used it on as well. Got tons of great shots with it.

My new camera (Canon Rebel T2i) has a nice 50-250mm but it has Image Stabilization. IF YOU CAN AFFORD A LENS WITH IMAGE STABILIZATION ** DO IT **. MASSIVELY better for long telephoto lenses as it takes out the small shaking of your hands - which close up might only move the image a centimeter or two around, but when zoomed in a hundred feet away, adds up to FEET of image shake. It really helps get MUCH clearer pictures when zoomed in using a long lens.

Lenses with Image Stabilizers are usually about 2X as much as ones without, but for anything over 200mm without a tripod, the difference it makes is WELL worth the extra cash.

gecko
10-13-2010, 12:24 AM
Lenses have a sweet spot for sharpness as well: http://www.digital-photography-school.com/find-your-lens-sweet-spot

Itchy
10-14-2010, 05:56 PM
***I wanted to say a general thanks to people posting on this thread, I have learned a lot of new things and any continued discussion of the matter is VERY appreciated.***

Darksky- I talked with a few really good photographers on flickr awhile back, they all said the same thing a fast 2.8f lens is one of the best lenses for chasing. When it comes to cameras I think of the body like a PC. It depreciates in value very fast but a good lens will last forever

davefootball123
10-14-2010, 06:55 PM
I will be getting a 35 1.8 as my walk around/portrait/macro lense. The 18-55 will also serve that purpose. The 55-300 will be my zoom(tele) and i may get a wide angle if i can afford one later on. But yes itchy get the fastest glass possible in ur price range.