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D200 & High ISO?

PostPosted: Fri Jun 01, 2007 4:30 am
by Quilb
Hey,

I am planning on buying the D200 soon, however i did a trip to Taronga zoo on the weekend and i took a lot of High ISO shots (I was using my S3 IS P&S @ ISO 800) Now i know a P&S will have more noise due to smaller sensor however will i get lots of noise at similar ISO on the D200?

PostPosted: Fri Jun 01, 2007 8:33 am
by gstark
Why were you shooting at 800?

With a DSLR, you'll also gain a potential advantage in that you can use faster lenses.

The real issue with noise though is to ensure that you have the correct exposure. Do that and your noise issue goes bye bye.

PostPosted: Fri Jun 01, 2007 2:36 pm
by PiroStitch
at ISO 800 on a D200 it doesn't matter. You can pretty much get away with viewing it on the screen at up to ISO1250 if the exposure is correct. If you print the photos out, the noise somewhat diminishes as well ;)

PostPosted: Fri Jun 01, 2007 3:11 pm
by Quilb
Very low light. I was there early in the morning and a lot of the animals like to hide in the shadows.

I was using 1/50 shutter and hand holding (a lot were too blurred i found after), still a little dark but was using ISO 800 and thats all my current P&S can do. The aperture was around 3.7 for most according to the EXIF data.

Will put an example pic as soon as i upload one to a website.

PostPosted: Fri Jun 01, 2007 3:17 pm
by Quilb
Here is an example pic, not the best but you can see what i mean.

Image

Exposure: 0.01 sec (1/100)
Aperture: f/3.5
Focal Length: 50.7 mm
Exposure Bias: 0/3 EV
ISO: 400


800 is of course worst.

PostPosted: Fri Jun 01, 2007 3:27 pm
by wendellt
at that focal length you can adjust shutter to at least 1/50 get more exposure hence less noise

focal length shutter reciprocal rule

PostPosted: Fri Jun 01, 2007 3:46 pm
by DaveB
wendellt wrote:at that focal length you can adjust shutter to at least 1/50 get more exposure hence less noise

Up to a point. The "reciprocal rule" (just a rule of thumb really) actually refers to 35mm-equivalent focal lengths, so if you were to stick to the "rule" you would say that you could get away with 1/(50*1.5) => 1/75s. Call it 1/80s, and that's only 1/3rd of a stop more exposure than the above shot...
Also, different people with different techniques and skills can hold at different shutter speeds, but none of this can help with a subject that's moving (consider the moving hands of the gorilla in that shot). This is the same as VR/IS not helping with most moving subjects.

It's true that increasing the exposure will reduce the apparent noise levels, and this is one of the reasons that people pay for fast lenses that are still sharp at wide apertures.

But I think another important factor here is that this particular shot looks like a crop from the original. Are we looking at a 100% crop? Because the standards of what level of noise is acceptable at print size are going to be different to what is acceptable at 100% viewing!
Given the apparent chromatic aberration I'm guessing that the lack of sharpness in this shot isn't just because it's noisy or due to movement. Critical focussing and "low" lens quality are also important to the perceived quality: improve these and the shot will look better (of course, make them perfect and the image noise may become more obvious ;)).
Again these issues are usually less apparent when viewing the whole image.

PostPosted: Fri Jun 01, 2007 4:01 pm
by Quilb
Thanks for that. I am unhappy with a lot of the shots i got on that trip. Only a few good ones. With the lightness of the camera and the low light i think a lot of blur got introduced due to me shaking and also the subjects moving added to this.

I notice on my S3 IS it says 6.0-72.0mm 1:2.7-3.5
Now from what i have seen its a 6x crop sensor.

Are the apertures comparable to that on proper lenses?

eg.

10mm focal length on SIS (35mm equiv of 60mm) @ f/3.5
compared to
40mm lens on D200 (35mm equiv of 60mm) @ f/3.5

would one image be brighter then the other?
only reason i'm thinking it would be is because of the larger sensor on the D200?



Edit: (In response to crop question. It's not a crop but flickr resized it when i uploaded)