Digital Noise - is it that important?

[GoLowDrew]

I'm looking at a Sony Alpha A100. Good camera, great price now.The reviews have all be positives except one factor - noise starts at 400ISO or above.Note: I don't own a DSLR so I have no experience.Questions:- When the light is low, the camera would be smart enough to use flash, so is noise still a problem?- When the light is low, we use a slower shutter speed, will the noise still be a problem? The A100 also has "Shake Reduction" so I can go maybe 2 step slower.I know it's hard to say what I'm shooting. But in general, is noise that important?There are other cameras that do well with low light, but they are out of my price range (Nikon D80).

[n2ho]

Good source to get answer for your questions:http://www.dpreview.comGeorge

[millster]

The Alpha A100 is a good budget camera. Hard to deny that, what with the Minolta underpinnings. High ISO is going to be used for a dark photo where a flash is either not desired or would have no effect or in order to compensate for the narrow aperture of a long lens and still be able to use a fast enough shutter speed to freeze motion as you would want in sports photography.The issue is that the smaller the sensor in the camera, the more noise it will produce. That's why point and shoot cameras are generally VERY poor in low light. My Evolt suffers from noisy high ISO exposures too but it still manages to be a very serviceable camera. To answer your questions:With the flash, if you use a low ISO equiv (100-200) then no. Noise will not be an issue. If you still shoot with a high ISO equiv, the noise will still be there. Slow shutter speeds even at low ISO will introduce noise on a digital sensor. Some of the photo cells on the sensor will get hot during the long exposure and stick or discolor. Most cameras (my limited experience with the A100 leaves me uncertain of it) have a built in noise reduction function to help with that situation. The camera will take the original exposure and then take a "blank frame" with the shutter closed and subtract the blank from the original exposure to remove the noisy pixels. It's highly effective. This type of noise is different from high ISO noise, however. The noise reduction will do little to counter that.Now, having said all of this, there are a number of programs out there that will process an image to smooth the grain from high ISO noise. You lose a little detail and sharpness but in most cases, it's acceptable. Especially if you're not looking to make a huge enlargement of the photo. I use one of these programs for all of my IR photos as both the small sensor in my Evolt and the nature of IR photography make for very noisy results. To sum it up, whether noise is important depends on what you're going to be doing. If you want something that will take decent photos in the dark and you don't intend to make huge prints out of them you'll probably be perfectly happy with the A100 as a starting point as there are ways of dealing with the noise that will still leave you with a usable photo.

[GoLowDrew]

From your Olympus E500, what ISO do you think it becomes an issue? And if you only go as large as a 4X6 print?Also, is that where 35mm film can out perform digital when there is low lighting?

[millster]

My E500 is noisy at 400+. At 400, it's basically similar to a moderate film grain. At 800 and above, it's very noticeable and to my eye, undesirable without some post processing even at a 4x6 print.This is definitely where 35mm will out perform digital. For some reason, even a large grain, high ISO film is more pleasing than digital noise. I'd be happy to post some sample photos tonight from the E500 to show you what the noise effects are and also a couple that have been processed to remove it if that would help you out. I think the E500 is very similar in its noise profile to the A100.

[GoLowDrew]

Yes. If you have a chance, post me a "bad" picture of how noise can look like. My choices are currently:1.Sony A100 - New lower price 10mp. Anti dust, anti shake.2.Nikon D50 - discontinued yesterday officially and only 6mp. My P&S is 6mp so I want more for DSLR.3.Olympus E500 (like yours) - The package 2 lens deal is hard to past up.

[millster]

Sure thing. I'll take a few samples tonight. The A100, as I mentioned is a decent choice. Minolta technology and also availability of Minolta lenses.The D50 is a VERY solid camera. Keep in mind that 6MP on a DSLR is much more usable than 6MP on a P&S camera due to the larger sensor. With the D50 being a full APS sized sensor, it has a much lower noise profile.The E500, I love. However, the small sensor makes low-light noise a problem and the 4/3 lens mount is too new to have a lot of available add-on lenses. That said, the two kit lenses it comes with aren't too shabby.

[GoLowDrew]

http://www.four-thirds.org/en/about/benefit.htmlHere is something about the 4/3 system. I wonder if it's just marketing or is it really better?

[millster]

Some marketing, some truth. I don't know that you necessarily get a shockingly better photo because of 4/3 lenses. I think you'll get that with any "made for digital" lens on a digital camera. Using a lens designed for a 35mm camera can result in poor image quality on a digital camera because the less-than-full-frame sensor size will result in the light not being properly distributed over the sensor. To some extent, the lack of support for 4/3 (Only Olympus, Panasonic, Leica and Sigma make the lenses) makes it a little tough to tell yet whether it will truly be superior.One thing to note with 4/3 that I forgot to mention earlier is that since the sensor is even less than APS sized, the crop factor is 2x rather than the APS 1.6x. This means that a lens noted as 50mm is going to function at a 35mm equivalent of 100mm. Just something to keep in mind.

[ZubenElGenubi]

Canon offers an in-camera noise reduction option (like millster mentioned) that is very effective. It works well at all ISOs, but will increase time between exposures.I am amateur astrophotographer and have seen an amazing evolution in DSLRs and processing technology. Noise reduction is one the most important aspects of image processing and it seems that Canon has made the most progress. I think they're at the top of the game as far as overall digital performance and lens systems are concerned, with Nikon a close second.I'd seriously look at the Canon 400D (or 300D if you don't mind a discontinued model).

[n2ho]

There are many noise reduction software such as Noise Ninja, Neatimage, Noiseware and so on, and they are much more effective than in-camera algorithms. The noise issue IMO is too much overinflated for many cameras. I use non-DSLR Panasonic FZ30. Since it has small 8 Mp sensor (1:1.8) noise is a factor, but even at ISO 400 you could get satisfactory results.Example (low light concert photo, ISO 400, no flash): If you go as large as a 4X6 prints I wouldn't worry much about noise, particularly for DSLR cameras. Look through Panasonic forum at http://www.dpreview.com/ and you'll find a lot of discussion about noise, comparison with different DSLR's and samples.