After reading "The Megapixel Myth by KenRockwell.com"
http://www.kenrockwell.com/tech/mpmyth.htm ,
I had second thoughts on buying the Nikon 8700, D70 seems to be
anytime better than 8700 in terms of speed, ISO, quality. The only
other advantage getting 8700 is its 8mPixel feature (apart from its
size/weight).
The 8700 also has a closed sensor - very important in the field (changing a lens on a DSLR in dusty or humid/wet environments is asking for trouble - lots of cleaning later as a minimum).
Is it true that difference between 6 and 8mPixel is marginal? Is
the noise in 8700 that bad compared to D70?
Certainly the noise of the 8700 is worse than most 6mp DSLRs. On the plus side, the extra 2mp does make a difference. Resolution and image quality are not the same, and more mp gives more resolution (all things being equal), but image quality might suffer if you crank in more noise reduction or are taking night shots.
The technical reason why this is so is because the 8mp sensor chip is in the same area as the 5mp sensor chip, thus each sensor is smaller, and area of the sensor determines the amount of light gathered. However, there are more sensors, so you can resolve finer details.
Now, the DSLR has a much larger sensor area, so it does work better in low light. On the down side, the images from DSLRs typically need some post processing, meaning more computer time.
So, which is better? That depends upons what you want to do with the camera. The 8700 has excellent macro mode, a decent quality lens, and a lot of zoom range built in too. The D70 will need at least 2 lenses to cover this range (and the kit lens most likely is just adequate - this is the case of most DSLR 'kit' lenses - Canon and Sigma too).
For many, the fixed lens pro-sumer camera is a better buy. For those wanting to go the DSLR route, consider spending at least $2000, if not $2500, to get what you need for creative photography (camera body, a couple of high quality lenses, a good strobe, filters, lens hoods, batteries, bag, etc). Make a list of what you need, price each item, then decide whether the increased cost is really justified.
Oh, there is a difference between the 5mp and 8mp images - more resolved details with the 8mp, and less noise under darker conditions with the 5mp. (this is 5700 vs 8700)
For general use (for me that includes hiking and backpacking too), I prefer a closed sensor system. For creative indoor use, the DSLR is great, but I really don't like to change lenses in the field - cleaning sensors is not my idea of fun.
Wayne
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Canon Digital Rebel, Nikon 5700, Nikon 8700, Panasonic LC5
