Stop Increments

travis_cooper · 01-03-2008, 11:59 AM

Okay, what increment do you use for your stops? I have always used 1/2 stops, but I notice a lot of, to me, weird aperture values like 6.7, or 7.1, which I know are 1/3 stops, but I never use them. So why do you use what you use? Is there an advantage to using one over the other, or is it just pick one and it doesn't really matter?

Jodokast96 · 01-03-2008, 12:06 PM

I go with 1/2 stops. For me, the extra full stop you get on things like EV compensation make up for the slight difference lost between 1/2 and 1/3 stop.

*m8o* · 01-03-2008, 12:12 PM

1/3 stops allows me to get the right exposure w/o needing incremental EV compensation determined by trial and error. As I use TAv almost exclusively, it allows the camera to use ISO 160 ... 240 ... 320 ... 640 ... 1250, etc, to get exposure closer to optimal on its own, again w/o trial & error. Also, when using M mode, more control over exposure when using the meter.

As my rear screen is broken, having the camera do it right for me is all the more important, as I can't preview presently!!!

wlachan · 01-03-2008, 01:15 PM

I like 1/3 better for fine tuning the exposure, but still stick with 1/2 because I need 1/180s for dumb A flash. Scroll through 1/2 is also much faster than 1/3.

Talisker · 01-03-2008, 03:04 PM

Well, my MX and M series lenses were 1/2 stops, so that's what I learned and got used to over 20-odd years, so it still does me on the K10! Never had any particular trouble getting decent exposures and I always shot on slide film (still do on my rangefinders...)

blwnhr · 01-03-2008, 06:23 PM

I used to use 1/2 but changed over to 1/3. No real reason, other than to check that the Bigma was actually f/6.3, haha. Just left it there, has given me more shutter speed options in the 1/60-1/250 window that I use the most.

Lowell Goudge · 01-03-2008, 08:11 PM

I change the setting depending on the lenses I use.

For K mount lenses since the lens operates in 1/2 stop increments, that is how I set the camera. This is useful because sometimes, when lighting is just on the "edge" of the transition between two settings, the 1/3 stop setting causes some inconsistency in exposure, between f-stops due to minor errors in metering or apature on the lenses. for KA mount lenses I set it to 1/3 because the camera controls this

PDL · 01-03-2008, 11:54 PM

ISO settings increment in 1/3 f:stops.
Film speed - Wikipedia, the free encyclopedia
Back in the old days, a rule of thumb (to saturate colors in slide film) was to underexpose by 2/3's of a f:stop - so to be consistent you would just set the ASA (yes, those old days) 2/3's of an f:stop slower than the film was rated.

Edit: Removed bad table - bad bad

pixelsaurus is correct (post#9) Here is the corrected table (comments included)
Ektachrome 160 -> 250 (did not work for IR Ektachrome though)
Kodachrome 64 -> 100
Kodachrome 25 (Boy did I love this stuff) -> 40 (just try shooting sports with this - high ISO settings are for wimps)
from Wikipedia on Kodachrome "When shot with a high quality lens, a 35 mm Kodachrome slide will hold detail eqivalent to 25 or more megapixels of image data [citation needed]." I like the "or more" - that stuff was pure gold.
Fujichrome 100 -> 160
Ektachrome 200 -> 320
Agfachrome 400 -> 640

So if it works by "understanding" the relationships of ISO/ASA by the numbers - why would you choose 1/2 stops. It is all about granularity and control.

Kodachrome 25 and a polarizer - under expose by 2/3's and you could get a clear blue sky to be just this side of black.

The Elitist - formerly known as PDL

*TomInJax* · 01-04-2008, 04:26 AM

Originally Posted by PDL

you would just set the ASA (yes, those old days)

Wow! Does that bring back memories!! Thanks for the trip back to the 70's!!!

By the way - I used tons of Kodachrome 25 back then. Amazing stuff!!

pixelsaurus · 01-04-2008, 06:31 AM

Originally Posted by PDL

Ektachrome 160 -> 100 (did not work for IR Ektachrome though)
Kodachrome 64 -> 40
Kodachrome 25 (Boy did I love this stuff) -> 16 (just try shooting sports with this - high ISO settings are for wimps)
from Wikipedia on Kodachrome "When shot with a high quality lens, a 35 mm Kodachrome slide will hold detail eqivalent to 25 or more megapixels of image data [citation needed]." I like the "or more" - that stuff was pure gold.
Fujichrome 100 -> 64
Ektachrome 200 -> 125
Agfachrome 400 -> 250

Maybe my logic is suspect but the latter ISO ratings (it seems to me) would result in overexposure.

Kaimarx · 01-04-2008, 08:58 AM

I recently switched to 1/3 because of my faster lenses at 1.4 and 2.8. I dont need as much compensation when using the faster glass.

PDL · 01-04-2008, 09:43 PM

Originally Posted by pixelsaurus

Maybe my logic is suspect but the latter ISO ratings (it seems to me) would result in overexposure.

You are correct - which is why my slides I took in Santa Fe came out so "weak" - oh well, not shooting slides for 30 years will cause you to remember "incorrectly". Please note the new table in my original post (#8).

Getting old is a b*tch. Had a 50% chance on which way to turn the dial --- and blew it. Even Elitists can be wrong from time to time.

However, the key here is to use the EV compensation of the K10D or any digital camera, with film, you really do not change the ISO (ASA for us old timers) - you could cook the chemistry - except with Kodachrome - that you do not cook.

The Elitist - formerly known as PDL

pixelsaurus · 01-05-2008, 06:21 AM

A number of years ago,I was shooting Velvia 50 in my Pentax MEF. I was on a boat leaving Auckland Harbour,NZ going on a whale hunt out in the Hauraki Gulf. There was a squall line moving across Auckland which I decided needed shooting. I could see in the viewfinder the exposure was 1/1000 at f/16,which I thought was a bit odd but ignored it. After having the slides processed,they looked ok visually but a little contrasty however the CD made at the time of processing was a disaster. All the images on it were way too dark. I then realized that the exposure compensation switch,which had previously been fixed in service,was playing up again. All shots were underexposed by 4 stops,which turned out to be serendipitous. Not only was the colour saturated but the fast shutter speed froze the wake behind the boat.Using ArcSoftPhotoSuite2000,I was able to salvage the images. The result was Auckland Skyline Now that I have PSE6 and the original slides and CDs (with me in the USA) ,it might be time to see what else I can do with it now.

ftpaddict · 01-05-2008, 03:46 PM

Haha, I woudn't know. I use a full manual and I just stop down to where I need to, then rely on my gut instinct and over/under-expose as I see fit. Most of the time, it works.

travis_cooper · 01-05-2008, 06:36 PM

Well, I just changed my camera settings today to do 1/3 stops, it seems more people like it that way than the 1/2 stops. I haven't really seen a good reason to stay with 1/2 stops other than it takes longer to scroll through the values, but have seen more good reasons to switch to 1/3 stops. We will see how it goes.