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Welcome to the Forum.
+1 @ much of Dave & Scott
ceyerly wrote:
using the lower ISO's. A habit to be broken.
I too am a "low ISO" junkie at heart. There's something ingrained into that psyche that says "low ISO" = best achievable possible IQ. To a degree, there is some truth in that ... ceteris paribus. However, if we stop to take the time to consider the other attributes that are compromised by our decision to latch on for dear life to "low ISO", then we can realize that our best achievable possible IQ may indeed warrant a higher ISO. Still, it's some tough medicine for this "junkie" to swallow, but here's a couple things that help me.
1) Most lenses are sharpest NOT wide open.
If I'm forced between my lower ISO and being up against the wall of my lens wide open (noting some $$$$ lenses are tack sharp WO), I'll typically be willing to move my ISO 2/3 - 1 stop to allow me to get off WO (read, wishful thinking by mfr's trying to be keep $$$ in check).
This is probably my most powerful reason for bumping ISO, considering this:
The low ISO junkie (this one anyway) wanted to have the best resolving capable film for being the detail junkie at the core of things. The fine resolving capability of the finer grained film, had me shooting Fujichrome 50, for its fine detail, while the K64 & K25 had similar qualities regarding color, etc.
So, if my objective is the finest detail retention, shooting low ISO through fuzzy glass WO, is a bit antithetical to the objective of detail (note, detail isn't always the holy grail). Thus, a recognition to the amount of impact to the image the difference in ISO makes vs. the aperture choice ... leads to a determination (glass depending).
Imo, this is really where the prime lenses come into play. Shooting our zoom WO @ f/4 vs. shooting a prime (50/1.8, 35/2.8, 85/1.8, etc.) at the same f/4 means we are shooting OFF WO, and more into the "sweet spot" of the glass.
But, in lieu of swapping out to the bag of primes, we carry the zoom, so when we make that choice we need to understand where our backs are up against the wall vs. where we have enough elbow room. In the case of shooting WO vs. bumping the ISO one stop, I'll typically move off of WO (unless I'm intentional @ WO for DOF reduction), and then am faced with a decision, to wit:
A) Do I reduce the shutter speed to offset the aperture, or
B) Do I increase the ISO to offset the aperture
Depending on my goals for the image, A) may incur camera shake or subject motion blur. It may warrant a tripod or reliance on IS. Factors that are for consideration on a case by case basis.
B) on the other hand really has little impact on the DOF or motion factors associated with the image. Raising the ISO one stop (especially @ 800 and below) and feeding it the light it needs doesn't degrade the image nearly as significantly as it did back in the film days or earlier days of digital.
The 80D (personal use here) suits this fine detail junkie well, enjoying it at base ISO the most ... but, it can still lend a helping hand with a few bumps or two without giving up the fine detail ... particularly when it affords you the opportunity to get off WO. The biggest caveat is when we go higher ISO ... AND ... underexpose. Going higher ISO and properly exposing (or slight +exposure) typically isn't a major problem.
Our other aspect for consideration is of course shutter speed and the use of it for camera shake vs. subject motion (stop motion / show motion). Most often we recognize that a blurry (camera shake) image @ low ISO is of less value to the overall image that a steady shot higher ISO. In that regard, getting off WO is a bit more subtle issue, but it still is an issue to give thought to.
Case in point, I rarely shoot my 100-400L II at anything less than f/6.3 ... staying off WO, even if just a touch. Same goes for my Sigma 50-100/1.8, I stay @ f/2.5. Run some test shots with your lenses and you'll likely find that most lenses have a noticeable difference between WO and that first stop. So, if I'm chasing best possible achievable ... ISO vs. WO ... imo, that one stop of ISO "hurts" less than mfr's wishful thinking that they achieved the same level of optical excellence WO as the rest of the lens provides.
Gone long ... and I know that WO wasn't Dave's point (more about DOF), but for those who struggle with being a "low ISO" junkie, we can take some time to ask WHY are we low ISO oriented, and realize that it is for the sake of the image. As such, it can be a question of "choose your poison(s)", and given the choice of WO (read optically softer) vs. higher ISO, the choice can be that moving your ISO higher IS the better choice. Same can / may apply to other scenarios ... with the salient point being ... no holy grail in all cases for "low ISO" at all costs ... so relax a bit, and bump your ISO a touch when warranted.
As to Dave's F/11 recommendation, I'd probably only go to about 6.3 or 8.0 to keep my ISO 800 or south, but the point really is don't feel stuck below 200. There does come a place where the higher ISO curve starts to be the greater "poison", and then this relationship reverses where I'll take WO (now the lesser poison) over uber-high ISO. But, we've seen some pretty sweet stuff in the 1600-3200 range (correctly exposed vs. underexposed) from a variety of folks (camera dependent) over the years. As such, 800 is "no fear" territory for me (with enough light) ... even though I'm always looking for 50 and a tripod.
Hope that helps with your "habit".
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