EM1 - Aperture? - Macro & Wide Angle

[KCrofoot]

Guys,

Underwater photography got me interesting in photography and not the other way around. Therefore I am not the best at using all the buttons on my camera. I have used a couple articles to fine tune the setting for my EM1 and have recieved some exciting results. That being said I am always trying to improve my craft.

Up to this point I have not changed the aperture or f stop during my dives. I have basically left it at F8.

Read an article recently about using different apertures for wide angle and macro. I am currently shooting the 60mm with an I-Das diopter on a flip and I have a new 7-14 pro lens with the 180mm dome port. I am looking to perfect shots so I would like to know when to use what aperture with what lens and diopter?

Cheers, Thanks ahead of time for your response.

 

[tursiops]

There are two considerations in setting your f-stop: sharpness, and exposure. I'll ignore exposure here, but it is of course critical.

Sharpness has two considerations too: focus, and resolution. You want both, but it is always trade-offs. You maximize resolution (the innate sharpness of a lens) by using an f-stop that is at least 2-3 stops more open than the smallest aperture...so typically f/8 or f/11. At that aperture and larger, diffraction effects are mitigated.

However, the other aspect of sharpness is focus, which also has two considerations: the plane of focus, and the depth of focus or depth of field (these are not quite the same but the difference is not important here). You need to focus (for example) on the rhinophores of the nudibranch, but only some narrow region closer to you and farther away will also be sharp. You can increase the size of that in-sharp region by using a smaller aperture -- say f/22 instead of f/11 -- but then diffraction effects get you and the image looks soft in sharpness rather than crisp.

So, weighing the various alternatives, go for f/8 to f/11, and just accept whatever depth of field you end up with with your lens, diopter, and working-distance choices.

 

[KCrofoot]

An article I read suggested to shoot fish at F8 but to shoot macro at F22. It also suggested for macro to try Bokeh shoots at F5.6 or F2.8.

Wide Angle - Shots with sun in the photo try at F16 or F22?

Any experience with these suggestions?

 

[Furnari]

As tursiops says, you'll lose sharpness to diffraction when shooting with a tighter aperture. It's sticking in my head that peak sharpness with the 7-14 Pro is around f5.6. However, you'll need to stop down a little more to get sharp corners for two reasons- the field curvature of the lens and optics of the dome. In my experience with a 170mm dome, f7.1 seems to work out fine unless I want nice sunbursts- in that case I'll go up to f16 but I don't like going higher than that if I want any detail in the non-sunburst portion of the shot. For the macro, you have to decide if you want to sacrifice sharpness for depth of field. IMO, I notice the loss of sharpness at f18 and above so I've never bought into the recommendation of shooting at f22. f8 is ok for the right subject as long as you're ok with the thin DOF and have good technique. With a diopter, working distance and DOF are already challenging, so you don't have much choice but to shoot at f22. Fortunately, the 60mm is pretty sharp even with diffraction.

 

[KCrofoot]

Furnari,

Appreciate the feedback. I have been shooting my 60mm at F8 so adjusting to a higher F setting should be interesting.

Are there any aperture settings different for night dives?

If you are shooting the 7-14 Oly Pro lens with the 170mm Zen Dome then you do not have the focus ring. What do you preset your focus on? On the ring I see (0.2, 1 -orange, 0.4, 2 orange, 1, infinity)?

 

[Furnari]

I use autofocus on the 7-14, and shoot through an Inon dome (also works great with the 12-40). Zoom gear fits, too. I typically use the same aperture settings for night dives...

 

[tursiops]

An article I read suggested to shoot fish at F8 but to shoot macro at F22. It also suggested for macro to try Bokeh shoots at F5.6 or F2.8.

Wide Angle - Shots with sun in the photo try at F16 or F22?

Any experience with these suggestions?

Avoid f/22 (too much diffraction makes the pictures soft) unless it is the only way to control the exposure.The article you read is not good advice.

You need a good photography class covering basic concepts; check with your local community college. I think.learning this piece-meal by asking questions on the web is a bad idea.