ISO 12.5 or even 7???

SAMBISU posted some great pics of Glacier National Park, I was in Idaho (with some of the fires, pray for rain). Both of us needed ND filters to do a proper job of some to get some longer exposure times.

I am loath to put layers of glass in front of the lens, a good set of NDs looks to be as expensive if not more so than a good prime lens.

I know in the short term the requirement is to bite the bullet and get a good set of NDs.

Longer term, the landscapers, etc should would benefit by going low w/ the ISO. We used to have Kodachrome 25, as well as, an special purpose Ektachrome at 7. I rented a 5dIII that did have a low (50) setting which did not impress me a bit (the low iso setting - the camera is pretty cool).

While I was indeed in the wilderness - am I a lone voice in said wilderness? Is the ND solution "good enough" and the manufactures will continue to push low light marketing? Any hope for a sensor based solution?

And lastly, suggestions on 77mm NDs would be helpful.

Mike

Personally, I'm a big fan of the Singh-Ray Vari-n-Duo. It's a variable ND filter stacked with a circular polarizer, too. I have the standard mount, but Singh-Ray also makes a thin mount. Even a thin mount version of the filter wouldn't be thin enough to prevent vignetting on really wide angle lenses, though. Below are some photos I've taken with the Vari-N-Duo--you should be able to right click and choose "Original" to see the full resolution picture (to check for quality using the filter).

http://farm8.staticflickr.com/7105/7...e855b397_z.jpg
Burgess Falls by budrowilson, on Flickr

http://farm8.staticflickr.com/7091/7...3a494f5e_z.jpg
Burgess Fall Tributary by budrowilson, on Flickr

http://farm8.staticflickr.com/7091/7...56d2c917_z.jpg
Samantha as Aphrodite by budrowilson, on Flickr

If you don't want to spend that much for the Singh-Ray, B&W makes some great ND filters, standard and thin mounts.

I would think the camera manufacturers could do such a thing. After all ISO is simply an electronic amplification of the very low level signal coming from the sensor. The sensor actually does not change sensitivity like film. So theoretically I would think they could offer a lower ISO setting unless it would cause some other problem.

No doubt some day sensors will be able to do this, but the camera companies would have to invest RD resources to make it happen. Right now it is a problem that is solved by readily available ND filters. I think camera companies RD will continue to push toward higher ISO with less noise. Who knows, they may work out using lower ISO as a side effect of the RD they are doing.I doubt it gets much of their attention right now.

Well, us Canoners are out of luck, but in MF world most digital backs go down to iso25, (maybe iso12).
Or on the film-front, there's Efke RB25, über-fine grained iso 25 black and white film, that you can pull down to 12 or 6 (i've got a few rolls, i'll let you know how they turn out), not sure if Velvia 50 can be pulled down to 25.

But back to digital, most cameras (according to dxo testing) don't actually do anything to the sensor to get it sensitive down to 25 or 50, they only throw away half the info for a longer exposure time. So you get longer exposures without the NDs, but no increase in quality or noise...

I've also heard that lower digital ISO's like 50 can affect IQ too!

After-all, the lens does consist of a few groupings of glass, so what's another ND layer gonna' do? :)

As long as you get quality filters and you don't stack them too much, you should be fine. If conditions permit and you're going to add an ND filter, then you should probably take off your UV filter if you use one.

The B&W ND filters are always considered very good quality. If you need to buy filters for multiple lenses or you also have a need for graduated ND filters to control parts of your image, then you may want to consider a Lee Filter System.