Just before going on a week's holiday to the south coast of England I decided to invest in a set of filters for my Sigma DP2M, for the first time in my life.
The system I have gone for is the new Lee Seven5 system and a basic starter set with a graduated hard filter, a graduated warming filter and a hard filter (2-stops). In addition and because I've always wanted to 'play' with one I also purchased the Lee 'Big Stopper' which is a 10-stop filter. Incidentally, I went for the Seven5 because with a 49mm adapater I can use the system on both my Sigma DP2M and my Sony RX-1.
Below is a picture of the filter holder and the graduated filter mounted on my DP2M (sorry for the poor quality: taken on my iPhone!).
One limitation when using the 'Big Stopper' with the DP2M is that there is no 'bulb' facility allowing any length of exposure. Therefore you have to work with the maximum exposure of 30 seconds. Personally, I would have preferred to work with exposures of at least one or possibly two minutes.
Below are two examples from the using the Big Stopper. I combined this with the hard graduated filter, first adjusting the filter to darken the sky and even up the overall exposure. Then adding the Big Stopper to the filter holder for the final picture.
Both exposures are at the base iso of 200 and at f4 and f7 (I had to adjust f-stops until I reached the magic 1/30th which with the Big Stopper would equate to 30 seconds).
Because of the length of exposure, even at iso200 noise is introduced to the capture. I may be fooling myself (I hope not!) but I find the Sigma DP2M noise really like grain and although I have smoothed it out in Lightroom I have not totally degraded the picture - I have left it at a level I would be happy with were this a film capture. As I still prefer film over digital (even though working with the DP2M and now the Sony RX-1 is beginning to make me question this preference) I am happy with the level of noise/grain in both shots.
Another question you may ask is, are the colours authentic? The answer is (obviously), not really. I have assumed that the Big Stopper not only affects the exposure range but does also lead to some darkening of the colours. One of the advantages of digital post processing (surely?) is to add artistic license and the Sigma DP2M is a good platform for doing this. Although I would point out that as dusk settles on the Solent, especially at high tide with no wind, there are some astonishing colour changes in the sea, with brilliant turquoise and beautiful deep blue tones which look almost unrealistic to the eye.
Incidentally, I have no association with Lee Filters, my only purpose is to show another means of expanding the functionality of the Sigma DPxM cameras.
I am going to write and post an article at my website comparing my week long use of the DP2M and RX-1 which will include other examples of using the filters. They are two extraordinary cameras and I have now come to a conclusion about when and how they are best used.