Sigma 10-20 / Subal - Magic filter combo

pmooney, how did you set the WB? I have a D100 and was thinking of trying the filters with the WB set to Auto.

At first I used auto white balance and had a reasonable result , and then tried manual white balance.

In all cases I adjusted the white balance in CS11 as part of my normal process ( raw workflow ). The images benefited hugely from this so I have a bit of work to do in the manual white balance department.

The measurement should be adjusted to 120mm based on a 7.5mm thickness.

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based on 120mm, extension = 38mm. So the 33mm ring is good and pretty close to that.

The dome is designed like your illustration 180F - it would seem that the only way to use the full surface of the dome would be for the "throat" of the port to be made larger.

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The glass itself has somewhat 125° curvature. No drawback that a small range of the glass surface is unusable as there’s still enough left for this lens. It’s just that the margin between ‘good’ placement and port shading is very small with such wide lenses and extension rings are not available within 1mm steps. But I assume it should be just fine with the 33mm ring. In terms of optics, it is. would be interesting to read your results.

Julian

Ultra-thin front filter ring may be required.  Many companies make these.

 

Cheers

James

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are those ultra thin rings sold without any filter element installed? or just a plain filter and removing the glass? do you have any ultra thin brand/model recommandation?

However, I just thought it should not be as critical as with a Nikon & 10-20 because I use a 1.6 crop camera.

thanks,

Julian

Excellent results! Glad to see that the Magic filter works in Australian waters too.

Alex