[JimJohnson]

Rumor has it that when Kodak Gold was introduced, the native ISO was 200. But marketing saw that Kodak still needed an ISO 100 version. So.... the engineers added a neutral density layer to the Gold 200. Kodak set a nicely profitable price for the ISO 100 version, but the market was still charging a premium for ISO 200 products, so in spite of the fact that the ISO 200 product cost Kodak less to make than the ISO 100 product, Kodak charged more for the ISO 200 version than the ISO 100 version.

The moral here is that even film manufacturers used neutral density when necessary.

[mikemike]

I read an interview with the Sigma CEO from CP+ and he was promoting that their new quattro cameras lead in low ISO.

[tromboads]

Just keep an nd filter in ya bag.

Simple dimple pimple whimple.

[Gimbal]

But what the OP thought and I also do think is that regardless of what comes out of the sensor it should be possible to just de-amplify (is that the word? Reduce?) the signal so that it equals f e ISO 25. Since quality is already extremely good at ISO 100 it doesn't need to get better. The benefit would be the possibility to use a large aperture in bright light

Doesn't work, once an area is overexposed there is no way to get the details back. A blown highlight will come back as a grey blob.

[RonHendriks1966]

It is a trade off, the lower the base ISO, the higher the signal must be amplified to achieve the higher ISOs. The higher the amplification, the more noise and the lower the dynamic range. Are the occasions you want ISO 25 so frequent that you'd give up ISO 1600? What about starting to lose dynamic range at ISO 100?

Maybe when we have sensors capable of clean ISO 51200 we will see a push towards lower ISOs, since that would mean a usable range of around 25-6400.

Does it really work that way from a technical point off view?

So wen I could choose between:
- iso 100 - 51.200
- iso 50 - 25.600
- iso 25 - 6400

I would definatly go for the camera with iso 25 - 6400!!!

[Gimbal]

I would definatly go for the camera with iso 25 - 6400!!!

Wouldn't it be cheaper to buy some ND4 filters?

[45 Mike]

Wouldn't it be cheaper to buy some ND4 filters?

Yep, but that is not the point here.
I have at times come upon a scene that was brightly lit, and wanted to capture the action, by using a slow shutter, or to control the bokeh by opening aperture, however the scene brightness puts either option out of the range of the settings available.
Now if I am out and about with JUST my camera, I don't have a bag, and I don't have an ND filter available, well I just do not get the shot I wanted. Sucks.

Even if I did have a bag, with a filter, if the shot was an action shot, by the time I get the bag open, find the filter that fits the lens, install the lens, the "action" could be over a long time ago.

In addition using a "filter" puts more glass in the image and more chance of aberration, dust haze, flare, ect. etc.

I just wondered if anyone else would prefer to also have low ISO settings as well as high ISO settings, to increase the photo opportunities available.

---------- Post added 02-22-14 at 09:53 ----------

Just keep an nd filter in ya bag.

Simple dimple pimple whimple.

what if ya got no bag, then there is no filter, and then, wham bam, no shot. That is the simple pimple.

[tromboads]

Even if I did have a bag, with a filter, if the shot was an action shot, by the time I get the bag open, find the filter that fits the lens, install the lens, the "action" could be over a long time ago.

I used to, you know keep the ND filter in my pocket, then just hold the filter in the hand that doesn't have the camera and hold it in front of the lens when I wanted to use it

"shrugs"

seemed quick enough really :P

[45 Mike]

I used to, you know keep the ND filter in my pocket, then just hold the filter in the hand that doesn't have the camera and hold it in front of the lens when I wanted to use it

"shrugs"

seemed quick enough really :P

Agreed, and thinking back to the days of my MX film camera, we certainly had no choice of ISO, after we loaded the film. We shot a roll at the ISO we chose at load time, all the way through 24 or 36 shots!

[JimJohnson]

Agreed, and thinking back to the days of my MX film camera, we certainly had no choice of ISO, after we loaded the film. We shot a roll at the ISO we chose at load time, all the way through 24 or 36 shots!

Well sort of. You could always, with a tad of caution, note that last frame used, rewind the partial roll, and swap film. When ready, you set the aperture to its minimum, shutter to its highest, left the lens cap on, reloaded the partial roll and shot the previously used number of frames plus a couple extra for safety.

I did this a few times, but it was far from a desirable thing to do.

[Gimbal]

what if ya got no bag, then there is no filter, and then, wham bam, no shot. That is the simple pimple.

But if you are willing to buy a camera that is always slow, you might as well permanently mount the filter on the lens. That way you will always have the ability to go slow. (I know, it's not really the same thing as it will affect the viewfinder and AF.)

But if you ask if we want a camera that is better in all directions of the ISO scale, then yeah, I want it.

[interested_observer]

It is a trade off, the lower the base ISO, the higher the signal must be amplified to achieve the higher ISOs. The higher the amplification, the more noise and the lower the dynamic range. Are the occasions you want ISO 25 so frequent that you'd give up ISO 1600? What about starting to lose dynamic range at ISO 100?

Maybe when we have sensors capable of clean ISO 51200 we will see a push towards lower ISOs, since that would mean a usable range of around 25-6400.

For the K5 there is the normal range of 100 to 25,600. There is the extended range of 80-51,600. They should be able to have a shifted range of say 25 to 6400. Essentially it is just digital signal processing the data after its pulled out of the sensor. Just set the ISO mode range that you are interested in and select the ISO.

In this way, you can essentially have what you - as the photographer, believe you need. I do not see the need for a fully continuous range of ISOs from 25 to 250,000. Segmentation is just fine.

[Gimbal]

As far as I know some of the lenses in the Q-format have a built in ND filter that can be enabled electronically. Perhaps something for the K-format to copy.

[KevinE]

Interesting discussion. I've never used an ND filter but definitely see the benefits.

[Kameraten]

... are numerous.
1. You have to carry them along all the time, just in case
2. You've got to have a number of them, to fit the lenses you need
3. You've probably got to have many densities which multiplies the number of filters needed
4. You get 2-4 extra glass surfaces, collecting dust and giving reflections
5. The reduced light transmission hampers both AF and manual focus. This is especially bothersome when you try to shoot using flashes and wide aperture but have rather weak ambient light, like in a studio or an outdoor night scene. If you use an ND8 filter you will not see very much through your optical viewfinder.