Luminous Landscape Forum
Equipment & Techniques => Mirrorless Cameras => Topic started by: Eric Brody on April 03, 2016, 02:41:30 pm
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I went to the Oregon Coast the other day, a beauty, and from Ecola Head decided I would try and emulate the style of the great but sadly recently deceased Chip Hooper with a long exposure of the ocean. I used my Fuji X T-1 and the 50-140 lens at f/5.6 with manual exposure of 6 minutes through a combination of a 3.0 and 2.1 neutral density filters. The exposure was pretty close but when I got home, I noticed horizontal banding in the image. I have used ND filters with some frequency to slo moving water and have even used this particular combination when it's quite bright without difficulty but usually for shorter exposures. I did a test in my home with a similar set, both filters, 6 minute exposure up but got only noise and color shift, as expected, no banding.
I've attached a cropped section of the file so that the banding might be more easily seen.
Any ideas as to why this happened?
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That's strange. The entire crop you've posted looks like it has a mesh or grid superimposed on it, in addition to the more obvious banding. The banding looks to me like an interference pattern…maybe the result of interaction between your external filters and the camera's internal filter stack. Likely scene dependent.
-Dave-
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Did you capture as raw or jpg?
I have taken my X-t1 to 4 minutes a few times and didn't it see this. I also have used the Fuji on a few night shoots taking 2' 35" stacks around 2 hours no issues noise or banding.
Again all raw.
That banding looks like some type of frequency noise but not sure what would cause it unless the motor in the 50-140 did. My 50-140 runs all the time and is a bit loud.
Paul C
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I've been making 5 to 6 minute exposures with the X-T1 and the 50-140, using a 10 stop nd combined with a 12 stop variable nd.
I've noticed in some images that I'm getting some slight light vertical strips, reminiscent of a water stain on paper, but quite fixable in Photoshop. It's almost certainly an artefact of the filters.
Your banding doesn't look like anything I've seen produced by a sensor, but something closer to the lens. 20 stops of nd is probably pushing what good quality filters are able to do.
I think it's also important not to let any sunlight fall on the filters, even at an oblique angle.
David
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Thanks for the replies. You've made me think about this some more. I now wonder if it is modified flare with the combination of filters and lack of a lens shade. I ordinarily use one but in this case did not because my filters are 77mm, the lens is 72mm and I needed a step up ring. This made it impossible to use the lens's regular 72mm hood. I plan to get a 77mm hood to use when I have filters on the lens but have not yet done so since I got the lens only two days ago. In my view camera days I often used a dark slide or a hat as a shade but did not want to stand there for six minutes :). I'll try another experiment with and without a hood and report back. Other ideas are still welcome.
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I've shot my X-T1 with 16 stops worth of ND for up to about 4 minutes with no such issues. Filters are HiTech and Lee Big and Little Stopper. I'm careful to shade the filters during exposure.
Rand
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It looks like the long time exposure noise reduction is not activated….
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I've had similar patterns show up on an E-M5 when the sensor got hot after many, many attempts at long exposure doing star trails. Is this a single attempt after many other attempts?
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Hi all,
Jaap, the long exposure noise reduction is on. I did have to wait for the dark exposure after each.
SZRitter, the example shown is one of four exposures made sequentially in an attempt to capture different water flows.
Thanks for the thoughts.
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I vote for light leaks. Make sure to shade and stop any gaps between holder and filter. Try the same settings/shot but out of direct sunlight (e.g. cloudy day or indoors) to test whether you still get them.