Canon EOS: 1/2 vs 1/3 stop increments for slide film?

[tomfrh]

Some of my EOS cameras do 1/2 stop increments, whereas some allow 1/3 stops. 1/2 stop increments can get you within 1/4 stop of any value, and 1/3 increments within 1/6 stop of any value.

In your experience does the extra precision of 1/3 stops vs 1/2 stops makes a difference in practice? Or is it splitting hairs?

E.g. would an EOS 1v in 1/3 stop increments mode nail more slides than in 1/2 stop increments?

 

[Poisson Du Jour]

Steps of 0.3 are very precise, and perhaps too precise for today's uses. With contrasty film such as Velvia (especially) it can result in quite bold and dark transparencies.

Factually, slides can be "nailed" with either 0.3 or 0.5 steps.

In 35mm, the large amount of contrast that is packed into a very small frame will always give rise the possibility of problems compared to the ease of metering with medium to large format. What can be difficult to do well in 35mm I have found is much easier done in parallel, on MF.

So, what will you be doing with the resulting transparencies?

If you are projecting, 0.3 steps is fine. So too, is 0.5.
If you are printing, 0.5 steps may be better.

I know what settings are perfect for me in all situations I come across (that means I wander from 0.3 to 0.5 to 1.0 steps freely according to what the scene is telling me).

No one setting is universally best for all situations unless you get away from the onboard meter and do things differently to sort out various tonal values and balance them. One is not better than the other, only different.

Another important thing to note is when you need to add or subtract exposure which can send marginal contrast scenes "over the edge" e.g. 2/3 is greater than a half: you will often have pause to ask, "is that too much compensation for this scene?" Visualising the scene with and without compensation is very useful.

My EOS 1N is set to 0.5 steps (like the over-specified 1V, it can also be set to 0.3 or 1.0) because I print from transparencies, never project.

A good, valid experiment is to shoot a scene in both 0.3 and 0.5 steps. It's a bit fiddly to wrangle custom functions. When the slides come back, critically examine highlight and especially shadow areas of the same scene at the different steps settings. The difference may appear slight, but sometimes it can be very noticeable. Shadows are where problems are easily identified if the steps are too small or, conversely, too large (which means highlights will wash out).

 

[tomfrh]

I am primarily projecting.

Steps of 0.3 are very precise, and perhaps too precise for today's uses. With contrasty film such as Velvia (especially) it can result in quite bold and dark transparencies.

This doesn't make sense to me. How can a finer degree of control impart detrimental character to the transparancy?

If you are printing, 0.5 steps may be better.

Again, you've lost me. How can coarser steps improve the outcome? I can understand it may be no worse, practically speaking. But better??

 

[Poisson Du Jour]

That finer degree of control, once multiplied, can be the glitch. A single 0.3 is an insignificant margin (that is my experience, yours may differ), and it is too small to be valid for my intended end purpose of producing prints. Tell me what you see with a trio of slides of an identical scene exposed at steps of 0.3 (then ±0.6), 0.5 and 1.0. For that you should include areas of highlight and shadow where ± step differences will be quite obvious.

The courser step (0.5) has a wide following among photographers printing from transparencies (e.g to the Ilfochrome Classic media and its lack of flexibility in contrast), because a small (but noticeable!) amount of inherent illumination is lost ( depending on the print process involved, additional light will be lost e.g. when ƃuᴉuuɐɔs ). All of my [manually metered] RVP 50 medium format work is produced in 0.5 steps, with an additional +0.5 baseline shift*. Why? Because at the print stage I will lost 0.5 step. So I start with a slightly brighter transparency, and end up with a very satisfying print. If I'm not printing, there is no baseline shift.

My work in 35mm (RVP 50) using the EOS 1N is made with either 0.3 or 0.5 steps. As I mentioned before, a shift of e.g. +0.6 is sufficient to blow out highlights, compared to 0.5 where they may well be preserved. Conversely, a shift of –0.6 is sufficient to flatten highlights and block shadows completely (with Velvia; Provia would give you slightly more leeway). Curiously, the small self-made memo card on my EOS 1N shows that I switched from 0.3 to 0.5 steps in June 2014 (I cannot recall what I was photographing!). Obviously, I had a scene at the time (no doubt not one of my standard rainforest shoots...) that I wasn't confident with at 0.3.
_______________________________________________________________
* But I do not use baseline shift with Provia 100F, nor any B&W emulsion.
I may or may not apply baseline shift to the as-yet untested Rollei CR200 transparency film.

 

[tomfrh]

I notice difference between 0.3 (velvia 50 at 50 looks quite different to velvia 50 at 40)

I notice more difference between 0.5, and more again between 1.0

Note I'm not talking about bracketed sets, merely general shooting, where I hope to get as close as possible with one shot.

 

[John Koehrer]

I guess the correct answer would be: Which do you prefer?

Once upon a time I preferred a slight under exposure for projection. Probably around -.3 When I was using slides
there wasn't any auto compensation so it was by guess and by golly.

 

[tomfrh]

Yes I know that +/-0.3 is noticable. If I shoot a roll of velvia 100 with EC -0.3 theyll General come out darker than I like.

But what I'm actually wondering is whether there is any meaningful difference between 1/2 stop increments and 1/3 stop increments when shooting slides (assuming you're not bracketing). Is losing that 1/6 stop of precision when you go from 1/3 increments to 1/2 increments worth worrying about...

 

[Bill Burk]

When I use my EOS I am flustered by the electronics.

But I do appreciate having the option between 1/3 stop vs 1/2 stop increments. I switch back and forth.

1/3 stop is useful when shooting film speed tests, because the results tie to the film speed.

But I find 1/2 stop more useful day to day.

I doubt you are "losing" anything by the choice of one over the other.

With other cameras, when I want 1/3 stop increments I pull out the 0.1 and 0.2 ND filters... It is kind of nice having that built in to the EOS.

 

[Chan Tran]

Either is sufficient accuracy but I prefer the 1/3 because it's more rounded.Most things photographic are in 1/3 step.

 

[tomfrh]

Either is sufficient accuracy but I prefer the 1/3 because it's more rounded.Most things photographic are in 1/3 step.

This is a good point.

 

[John Koehrer]

If the slides are too dark for you at -.3 you'll probably like box speed or +.3.
I'm assuming you are viewing them on a screen, not a light box, they will look different.

 

[trondsi]

I am using full stops only these days, as I am shooting slide film on the old Nikon FM. Most of the slides come out great, but I sometimes wish I could do half stops, particularly when using the average of two meter readings. So for me, half stops should do the trick.