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View Poll Results: My top picks are:
Olympus E-330 3 4.55%
Olympus E-500 9 13.64%
Nikon D50 15 22.73%
Nikon D70s 3 4.55%
Canon Rebel XT 9 13.64%
Canon 20D 11 16.67%
Pentax *ist DL2 5 7.58%
Waiting for Panasonic's DSLR 2 3.03%
Waiting for new announcments this month 6 9.09%
Haven't decided yet !? 3 4.55%
Voters: 66. You may not vote on this poll

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Old Feb 21, 2006, 11:48 AM   #111
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How much better is the D50 comapred to the E-500 in noise performance ? Is it that different ?

Can you send me an image shot with ISO 1600 with you Nikon ? Please.
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Old Feb 21, 2006, 12:24 PM   #112
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The only way to compare noise in one versus another very accurately is to take photos of the same subjects, in the same conditions, using similar exposure times. If it's a high dynamic range scene, noise can be more obvious in underexposed areas, too (especially if briightening them later). Even camera temperature comes into play (higher temperatures can result in higher noise levels).

Also, one channel may have higher noise compared to another (for example, blue versus versus red), so subject plays a large role.

A photo of a subject that's evenly lit in better light make show far less noise compared to a photo of a subject in poor light.

In controlled conditions tests I've seen, my best estimate is that the D50 probably has at least a 1 stop advantage compared to the E500 (with the difference much more noticeable if you try to push the E500 to ISO 1600, snce it's noise appears to become higher at a much faster rate over ISO 800 (noise curve is not linear). IOW, the D50's ISO 1600 is probably just as clean (or more likely cleaner) as ISO 800 from the Olympus with most subjects and conditions.

Keep in mind that the "native" ISO speed of the sensor used in the E-500 is through ISO 400. Everything past that is using "ISO boost" (which typically means that values are being multiplied in the raw data, after it's gone through the analog to digital converter, versus being amplifed at the analog level prior to the A/D converter. On noise tests I've seen, the E-500 is a bit better for visible noise compared to the E-300. But, it appears to come at the expense of smoothing of some detail at higher ISO speeds, too.

There is no free lunch.

You've got a smaller sensor, with more megapixels in a model like the E-500. That means the photosites for each pixel are smaller and not as able to gather as much light (because they have a smaller surface area). That means more amplifcation of the signal is needed for equivalent sensitivity to light, increasing noise levels.

Any choice is a compromise.

Sure, advances are being made in things like microlens design to help amplify the light hitting photosites. Ditto for image processing to help reduce the appearance of noise (at the loss of some detail). But, none of the manufacturers are standing still improving their technology, and a smaller sensor can have some disadvantages, all else being equal (and it never is).

If you are not going to be shooting in existing light very often, and are happy with the results you get using noise reduction tools when higher ISO speeds are necessary, then the differences in noise may not matter to you.

But, if you want better high ISO peformance, I'd look to a model with a larger sensor.
To Olympus' credit, they do now offer some zoom lenses that are brighter than the zoom lenses you can get from other manufacturers to help offset their higher noise. For example, the Zuiko 35-100mm f/2 lens (which would give you same angle of view you'd get with a 70-200mm lens on a 35mm camera).

But, this lens is pretty pricey (in excess of $2,000), and you have a lot of choices for lower cost f/2.8 zooms for other manufacturers' DSLR models. It's a very high quality lens from most accounts. But, not everyone has the budget for lenses in this price range.

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Old Feb 21, 2006, 1:18 PM   #113
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How is the ISO influence the shutter speed ?
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Old Feb 21, 2006, 1:31 PM   #114
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Idan wrote:
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How is the ISO influence the shutter speed ?
Each time you double the ISO speed, you can use shutter speeds twice as fast for the same aperture and lighting while getting the same exposure.

P.S.

To get a better idea of how ISO speed, lighting, aperture and shutter speed are releated for proper exposure, see this handy online exposure calculator (film speed in the calculator is the same thing as ISO speed):

http://www.robert-barrett.com/photo/...alculator.html

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Old Feb 21, 2006, 1:46 PM   #115
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By all means, thank you. This was a really educational information for me,

If I want to shoot a portrait and getting a shallow depth-of-field, I need to use a lower aperture setting (lower f) that means that the diameter will be larger and more light can comes in so I can shoot with faster shutter speed for each ISO settings, is it right ? :?
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Old Feb 21, 2006, 1:51 PM   #116
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Another question:

If I want to shoot with low aperture and High speed shutter the lower the ISO isthe lower is the aperture ? am I right, seems confusing I tought that when I'll use Higher ISO settings I'll have more speed for taking pictures with lower f settings.

So If I want to shoot at low light and getting a nice bokeh with a portrait shot I need a lower ISO setting, thats seems odd, cause I tought the higher ISO settings will give me the opportunity to shoot with lower f settings and get more shutter speed ?!?

or the opossite is true, I will get more speed for a single aperture when I use a Higher ISO settings ?

BTW: I tried both Noine-Ninja and Neat-Image and as far as I've noticed Noise-Ninja out performs Neat-Image and gives a clean image out of every noisy 1600 ISO photos I've tried. (WOW)

Knowing more really give me another prespective of wich DSLR to buy and what is realy important in a DSLR and what is not.

Nikon D50 seems a great choice for a starter with a low price and great low noise performance at high iso settings seems like a best deal.

I feel like a student in Steve's-Digicams School

[align=center]THANK YOU STEVE





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[align=center]Let us know and help others to decide. VOTE NOW !
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Old Feb 21, 2006, 2:23 PM   #117
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You would want to use the lowest ISO that allows you to achieve the aperature/shutter speed combination you desire. If you're already wide open at the lowest ISO with a proper shutter speed, increasing your ISO will not help you at all as your camera is already at its widest..all that will change is your shutter speed.

As JimC said, increasing your iso 1 stop, allows you to double your shutter speed. Where increasing your ISO would help, is if you could not achieve fast enough shutter speeds (say below 1/60th) at your chosen aperature. I doubt that you would be in a portrait situation where you would need an ISO over 400...if you are, you aren't lighting your subject properly.

Also, I'm not sure if your clear as to what Bokeh is. Bokeh is a subjective term used to describe how pleasing the out of focus area is in an image (specifically the highlights and how well the subject stands out from this background. There is no true measurement or chart that you can use to measure Bokeh. Bokeh is a term relative to the lens in general as opposed to the lens at a specific aperature.Also the camera has little if any effect on bokeh. 10 experts will give you 10 different opinions as to bokeh quality. When considering consumer grade (or any grade IMO) lens, bokeh is not really high on my list of things to consider.
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Old Feb 21, 2006, 2:28 PM   #118
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Idan wrote:
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If I want to shoot a portrait and getting a shallow depth-of-field, I need to use a lower aperture setting (lower f) that means that the diameter will be larger and more light can comes in so I can shoot with faster shutter speed for each ISO settings, is it right ? :?
Aperture, as expressed as f/stop, is a ratio between the focal length of the lens and the area of the diameter of the aperture iris opening.

So, if you have a larger aperture, more light gets through. As a result, you can "expose" the film or sensor faster by using faster shutter speeds for the same lighting and ISO speed.

ISO speed is representitive of how sensitive the film (or sensor) is to light. So, if it's more sensitive (higher ISO speeds), you can expose the film or sensor faster for the same lighting and aperture.

With a sensor, you're just amplifyng the output of the signal generated by photons hitting the photosites to achieve the extra sensitivity as you increase ISO speeds. If you're using film, different emulsions make higher ISO speed film more sensitive (at the expense of larger grain, which is similar to the noise you see when using higher ISO speeds with digital).

They are all related to each other, as you can see by playing with the exposure calculator.

Aperture also impacts depth of field. A larger aperture (smaller f/stop number) will have a shallower depth of field for any given focus distance and focal length. Usually for portraits, the reason you use a larger aperture is to help your subject stand out from distracting backgrounds, versus trying to get faster shutter speeds (the idea is to make the background so out of focus that it's not noticeable).

Indoors in low light (unless you're using a flash), you may not have any choice but to use a larger aperture, even if you don't want/need a shallower depth of field, in order to get shutter speeds fast enough to prevent blur from camera shake or subject movement.

You'll often see lenses with larger available apertures (smaller f/stop numbers) referred to as "fast" lenses (because you can get faster shutter speeds with them, not to mention that the AF sensors can see better since they get more light).

Having higher available ISO speeds isn't necessarily just an indoor thing either. You may want to use a smaller aperture to increase depth of field so that more elements in a scene are in focus. So, increasing ISO speed is one way to achieve that without your shutter speeds dropping off too slow with smaller apertures.

I posted a photo yesterday where I used an ISO speed of ISO 400 with my KM Maxxum 5D for an outdoor photo. I was at an aperture of f/11 for the shot (even though I could have used an aperture as large as f/4 with the lens I shot with).

I used f/11 to try and get both the foreground and background elements in the scene acceptably sharp, and kept it at ISO 400 to keep noise levels low. If I would have shot with ISO 100 or 200 instead, I'd have needed to use a larger aperture to get shutter speeds as fast for the same lighting.

You make tradeoffs and compromises for photos, depending on what you are trying to achieve. See my comments on camera settings in this thread when I discussed what I used for a photo, and how my choices only let me use a shutter speed of 1/100 second (which can be slow enough that you'll get some blur from wind blowing foilage, etc. in some conditions).

http://www.stevesforums.com/forums/v...mp;forum_id=90


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Old Feb 21, 2006, 2:29 PM   #119
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Actually the shadow of depth-of-field was the first thing that took me to look into DSLR I remember one time the we were in London and my father took a picture of my brother on a bench, and this picture was so amazing, poping out the subject from the background was really a great thing, of course 10 years ago it was taken with a film SLR and not the digital ones but still you can't get it with point and shoot cameras, no matter how you try it.
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Old Feb 21, 2006, 2:36 PM   #120
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1) So are we lookingmostly at the large aperture number on the lens, or the minimum aperture of the lens has any significant value or all the lenses has the same lowest aperture number ?

2) Do you think KM will have lenses in the future by Sony ? (I like the AS anti-shake option)
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