#1. "RE: Why is Nikon's Base ISO 200?" In response to Reply # 0
It's an engineering decision made during the sensor design stage. A lot of factors go into the decision.
Fundamentally, all sensors are designed with a base ISO at which operation (sensitivity, noise, accuracy) are optimal. Nikon frequently chooses ISO200; some other camera makers make other choices. There are arguments pro & con about various base ISO decisions, as you might imagine.
If a camera operates optimally at one ISO or another, the functional difference between the two different setting (ISO100 for Canon, ISO200 for Nikon) makes absolutely no difference to my own (critical and composition) decisions during actual photography. There are a number of photographers who have particular use for digital cameras which offer a base ISO100. Search for the relevant threads on Nikonians to read about such preferences and the reasoning behind them.
#3. "RE: Why is Nikon's Base ISO 200?" In response to Reply # 2
>higher base iso allows for faster shutterspeeds
Right on, and clearly of importance to a lot of shooters (including me), but not those who prefer a lower optimal base ISO while deliberately running slower shutters. Frankly, I can no longer tell the difference between identical shots made at ISO100 and ISO200 even when printed at 16"x24", so I guess I also no longer understand the interest which some shooters have in ISO100.
I was also going to suggest that Nikon's engineering design choice of base ISO200 is a holdover from its CCD days. But the D60 (CCD), D80 (CCD), D2X & D2XS (CMOS), D200 (CCD) all have a base ISO of 100 so that kills that idea.
#4. "RE: Why is Nikon's Base ISO 200?" In response to Reply # 2
>higher base iso allows for faster shutterspeeds
...or, greater DOF. Coming from using Velvia (ISO 50) on my F100, the versatility of using a base ISO 200 on my D700 makes a big difference when walking around. I win with a faster shutter speed, greater DOF, or a combination of both. Even with the base ISO 200 I get a broader range of use when light starts to drop off. That's even before I have Auto ISO kick in... which is fabulous. Naturally, using a tripod makes this somewhat less significant, yet, it does allow for improved range to get sharper images too.
While I like all this, the only drawback I see is when I want to intentionally blur things... like waterfalls. Even with a ND or C-Pol on the lens, ISO 200 tends to be a bit limiting for such usage.
Originally, I thought ISO 200 would be bad, given my tendancy to shoot ISO 50. I was still thinking "grain" and lesser image quality given the faster speed, but this is largely imcomparable given the technology of the D700.
#5. "RE: Why is Nikon's Base ISO 200?" In response to Reply # 4 Fri 10-Apr-09 06:47 PM by agitater
I don't think a sensor's base ISO has much to do with control over DOF. But high ISO/low noise capabilities in Nikon bodies means that we can almost completely ignore auto ISO because of the freedom we have to choose any aperture/shutter combination (to achieve the DOF we want) without having to worry about noise creeping in to ruin our shots as ISO automatically floats around to help make a good exposure. Did I miss your point?
The more I think about it, the more it seems that a sensor's base ISO is irrelevant given the quality of most sensors on the market right now.
I still have a nagging feeling that I'm missing some important point about an ongoing need for lower base ISO in digital sensors. What am I missing?
Really exotic water blurs (is that the sort of effect you mean?), I think, work best when shooting off a tripod, POD bean bag or some other support. A base ISO of 200 combined with a slow shutter (1/2? 1/5? 1/10? 1/15?) provides a lot of water blur. For longer exposures to achieve exotic water blur effects, a tripod is a must and I think the difference between ISO100 and ISO200 becomes so small it might not even be a factor. I'm suggesting that achieving a mist or liquid effect using a 5 second shutter off a tripod will create essentially the exact same results at both ISO100 and ISO200. There are bound to be exceptions which some exotic shooters can probably point out, especially for post-processing and large print sizes.
#6. "RE: Why is Nikon's Base ISO 200?" In response to Reply # 5
What I was driving at is the fact that a higher ISO rating will allow for either a faster shutter and/or a smaller aperature, hence the opportunity for greater DOF. This doesn't have to do with the base ISO of the camera per se, but is relevant given the fact that it is faster than what I've been using in Velvia (ISO 50)... so it buys me 2 stops. In terms of walking around, it is excellent to be able to hand-hold shots with greater latitude, again, even before going to Auto-ISO to compensate for lower levels of available light.
While I've always gone with the lowest grain possible, it appears that in digital shooting, this is significantly improved from that of film, eventhough the ISO is greater.
The only drawback that I have with this is when compared to shooting waterfalls at ISO50, the ISO200 would be harder to slow the shutter under certain circumstances. The use of a tripod is a given under these conditions, but this doesn't change the fact that the ISO might be too fast to allow for sufficient blurring of the waterfall. Of course, the ambient light, the speed of the water, etc. also plays a key role. Normally, I'd expect to use about a 2-4" shutter speed.
#7. "RE: Why is Nikon's Base ISO 200?" In response to Reply # 6
>The only drawback that I have with this is when compared to >shooting waterfalls at ISO50, the ISO200 would be harder to >slow the shutter under certain circumstances. The use of a >tripod is a given under these conditions, but this doesn't >change the fact that the ISO might be too fast to allow for >sufficient blurring of the waterfall. Of course, the ambient >light, the speed of the water, etc. also plays a key role. >Normally, I'd expect to use about a 2-4" shutter speed.
I think I understand your concern. I also think you'll be able to find the right aperture/depth of field and shutter speed to make the shots you like best. There are an awful lot of great water shots out there that have been made using digital SLR bodies at ISO200.
Velvia is a lot more forgiving than any CCD or CMOS sensor on the market today, especially when it comes to capturing dynamic range. On the other hand, I think you'll find that shooting the D700 at ISO200 will provide you with the exposure latitude you need to capture some really wonderful water blurs.