Olympus M.Zuiko 9-18 mm: Background too dark

Dear all,

I'm using an Olympus E-PL6 with the M.Zuiko 9-18 mm wideangle lens, PT-EP10 housing, Zen Dome and two Inon z240 Typ 4 flashes with diffusors mounted.

I did around 30 dives with this combo since March 2014, all in the Mediterranean sea. I get excellent pictures at F 8, 1/125 sec, ISO 200, but they all have a very dark background (very dark blue).

If I use F 6.3, the background resembles more what I see during the dive, but the corners of the pictures are too soft for my taste.

I tried adding a +2 Diopter. This improved sharpness in the corners, but I have the impression that it degrades overall Image quality.

On my last dive, a wreck dive at 44 meters depth, I tried out F8, 1/100 sec, ISO 400. The background is o.k. in my opinion, but I lose some IQ due to the higher ISO, and the fishes are a little blurred because of the longer exposure ...

I would really appreciate your advice!

Best Regards,

Philip

P.S. Examples enclosed are (1) F8 1/125 sec ISO 200, (2) F/8 1/100 sec ISO 400 and (3) F6.3 1/100 sec ISO 200 + Diopter. All Pictures were taken at a depth of between 40 and 45 m.

... and here are 1 to 1 crops (in the same order, 1st crop being derived from a different source picture to illustrate the possible level of detail)

... and finally, a picture of the same wreck taken with my old camera (Panasonic Lumix DMC-LX3 with Inon UWL-100 wide angle lens and a single Inon z240 type 4 strobe) at F 2.3 1/40 sec ISO 100. The brackground is much, much brighter!

Shutter speed will control the colour of the water

Dear Tim,

thank you for your answer.

I'm aware of the fact that it is the amount of ambient light getting to the sensor determining the brightness of the background. However, there are several ways to achieve this (e.g. lower F value). It is also possible to increase the sensitivity setting (=higher ISO) to get a similar effect.

I would be interested in the settings other users of this lens use. The tutorials on the internet mostly recommend F8 1/125 for MFT wide angle, that's why I started with these settings, ending up with the dark backgrounds :-( I've seen a lot of pictures on the internet even taken at 1/160 sec having a lot brighter backgrounds than my pictures. That's why I started this topic.

Best Regards,

Philip

I'm aware of the fact that it is the amount of ambient light getting to the sensor determining the brightness of the background. However, there are several ways to achieve this (e.g. lower F value). It is also possible to increase the sensitivity setting (=higher ISO) to get a similar effect.

The difference between changing the shutter time and F or ISO is that the latter two affect both the ambient and strobe light to the same extend. In contrast, shutter time only affects the ambient part of the lighting because 100% of the strobe pulse will be captured even at the fastest shutter.

Bart

I've seen a lot of pictures on the internet even taken at 1/160 sec having a lot brighter backgrounds than my pictures. That's why I started this topic.

 

 

Philip there are quite a few factors other than camera/strobe settings that will affect how much ambient light there is to capture. Some of these factors: depth (you seem to be diving quite deep), amount of sunshine above (is the sky clear?), position of the sun, direction you're shooting relative to the sun, etc. This is how someone is getting brighter backgrounds with a faster shutter. Try shooting up and into the sun (don't necessarily need to frame the sun in your shot).

Hope this help.

I like the blues on the 2 Oly shots better, IMHO. Nice dynamic contrast with the color on the wreck. The first, you're simply too far away and trying to light too large an area.

One of the things you're seeing is much, much greater detail and dynamic range, and smooth transistions are going to look darker at the same exposures.

Just adjust your shutter speed a bit if you want it lighter.

Jack

Thank you for all your answers, I will experiment with slower shutter speeds. However, one big advantage of the LX-3 / Inon Combo is that the pictures are quite sharp to the edges even at F2 ...