Less noise shooting lower res than the camera is built for?

[paddyhazard]

I'm just getting into photography and have a lumix fx38 (fz35 for americans) and am loving it. I know that with a lower res for the same size sensor you usually get better high iso performance which is one of the reasons i went for the now older fz38 instead of the fz100 with 14MP. I still think 12MP is more than i'll ever need so wondering if i switch it down to 10 or 8 MP, will the camera stretch those over the whole sensor, thus giving me better low light performance or is the sensor built for 12MP shooting at a lower res just crops the area on the sensor being used? Low light quality isn't really that important for me as I prefer taking shots outside so I was kind of just wondering.

Thanks

 

[luminosity]

I'm not sure what kind of quality you're looking at, at least when you compare it to a high ISO legend like the D3/700, or the current king, the D3s. All three feature just twelve megapixels, and that does help a good deal.

 

[OreoCookie]

Just don't: the in-camera resizing algorithm will for sure do a poorer job than whatever image editing app you're using (Photoshop or Pixelmator, for instance). Always capture at full resolution. You can always reproduce the effect of `shooting at lower resolution'* in your computer afterwards. However, if you shoot something at lower resolution, you can never get the additional megapixels you've lost back.

* The camera always captures images at the sensor's native resolution. The camera uses an algorithm to resize the full-res image to whatever lower resolution you've selected. Unless you choose 1/4, 1/9, etc. of your resolution, you will introduce additional artifacts.

 

[paddyhazard]

I'm just wondering with a point and shoot, with a relatively small sensor, if you can increase the high iso performance a little bit by shooting lower res. If when you reduce the size size of the photo from your camera maximum resolution, whether the camera will now use the whole of that sensor for 8 or 10 MP, thus decreasing the pixel density, or if the sensor has an set pixel density and reducing the resolution just uses less of the (already small) sensor.

I know any point and shoot high iso performance is very limited by the sensor size and i doubt the above would make much of a difference but i just wondered for those rare times I'd want to use an iso of 400, if reducing the resolution will increase the quality a bit.

 

[paddyhazard]

thanks OreoCookie so the camera will always capture at 12Mp and just re-size it to a lower res? That makes sense.

 

[Phrasikleia]

I know any point and shoot high iso performance is very limited by the sensor size and i doubt the above would make much of a difference but i just wondered for those rare times I'd want to use an iso of 400, if reducing the resolution will increase the quality a bit.

No. The sensor's cells are only so sensitive, and asking the camera to process your images to a lower resolution won't make its sensor any more efficient at gathering light.

 

[GoCubsGo]

Don't you lose some quality when you push the ISO down below the camera's base ISO?

 

[luminosity]

Don't you lose some quality when you push the ISO down below the camera's base ISO?

Yes, because the camera has to interpolate just as it does past the max native ISO range.

 

[jackerin]

I'm just wondering with a point and shoot, with a relatively small sensor, if you can increase the high iso performance a little bit by shooting lower res.

Pretty much the only camera(s) I know that has this kind of function is Fuji's EXR-series, but they make their own custom sensors. You can read more and see samples here and on other reviews: http://www.dpreview.com/reviews/Q210grouptravelzoom/page4.asp

 

[bsamcash]

The sensors always capture at one resolution in its RAW format, then converts it to JPEG at whatever resolution you set. Your best option is to get a camera that can save in RAW then removing the noise in post.

 

[a.jfred]

Always shoot at the highest resolution you can, at the lowest ISO you can. Even if you don't shoot in RAW, there are programs that remove noise.