Using the right camera for the job is paramount when you have a client to answer to. Both these cameras offer up amazing image quality, but in different ways.
Nikon or Canon these cameras are not, both the sigma and Pentax are slow and precise tools. Not for every photographer by any stretch of the imagination. However, if you’re looking for image quality over all else, these are cameras are certainly worth considering. The concept of the innovative Sigma Foveon sensor going up against the raw size and power of the Pentax is the main area of the review. One thing to keep in mind while reading this head-to-head, is that the Sigma is now available for a fraction of the Pentax price tag.
How we tested the Cameras,
During the testing process we set up a number of shoots. One was in central London white another was a beach location. I had no doubt that the Pentax was going to be amazing in the studio and I have used the Sigma many times for client shoots, so I knew the quality it gave. What I really wanted to do was see what these cameras are like to live with outside of the studio I set a goal in mind for the cameras – a tricky shoot with a horse on a beach for the last test. The winning cameras would be the one I felt most comfortable with for the complicated shots I had in mind.
Both of these cameras were designed for one thing: quality :- both models are slow fine tuned tools. They are designed for careful thought and use, and the two of them can deliver equality breathtaking results when used in the right way. I’m looking for which one gives me the confidence to let my creative mind run free. Does the cropped Foveon sensor match the 44 x 33mm CCD Sensor in the 645D? Let’s find out…’
Camera build and handling
The Pentax 645D
There is not much bad to say about either of the cameras when it comes to build quality. Sigma lands the first blow with wonderful and innovative Foveon Pentax gets night back by having a shutter exposure check release. Anyone who has used a medium-format camera will know of the lag created by these huge files, Pentax has thought round this problem in a clever way. Neither camera has a fast frame rate. The Pentax 645D gives a fixed 1.1fps, whereas are the Sigma is faster, but with a longer processing time and limited buffering. Both cameras are very slow in terms of the D800.
Both cameras fit in the hand well. The Pentax has a large grip, which aids the balance and poise of the medium-format-style body, housing a large 44 x 33 mm CCD sensor. For the size, the 645D is surprisingly light, nimble and easy to use. Having two tripod mounts on the Pentax is rice as is the massive viewfinder. The Sigma has some way to go in the ergonomics but once you find the buttons it does get move fluent to use. Having a quick menu to get to all the things you need is very handy. Again… the D800 is better than both cameras on this front.
Sigma SD1m
The Sigma SD1 is small, just a little smaller than a Nikon D700. For a body this size it is rigid and tough. Neither cameras are pretty, but they’ve been designed for a purpose. The Sigma has one of the most amazing sounding shutter releases, clicking as if it will last a lifetime. Also, note in the photograph above the hot-swappable, CCD protector & IR filter. Remove this to convert the camera to shot Infra Red Photography.
Ease of use, quality of interface
Sigma SD1 Merrill: 7/10: Built to withstand the elements, clearly function before form, no style points
Pentax 645D: 7/10: Well-planned and quick to learn, very light and nimble for a medium-format body
Special features on board
Both cameras are built around the concept of the sensor and the fact that image quality is key. The Pentax has a 44 x33mm medium-format size sensor (Kodak CCD) whereas the Sigma has a much smaller cropped sensor (23.5×15.7mm). The Sigma is simple, and this is reflected in the menu system. There are no fancy shooting settings or enhanced modes. The main feature of the camera is the much-speculated Foveon sensor. The X3F (RAW Sigma file) is amazing and the sensor is build up of three sensors in a stack. Each sensor picks up the colour value form each point. Sigma status this is ‘the only sensor in the world to really capture true colour. Just like film’ In theory it works and in practice it’s pretty much stunning. As a word of caution though use the Sigma Pro software to convert your files and don’t shoot in JPEG. The amazing dynamic range of the camera gives wonderful colour rendition and breathes new life into B&W photography.
The 645D has a 44 X 33mm sensor with 6 micron photosites
There are some downsides to this camera, though (hopefully limited to the early generation of the model). Processing power is lacklustre, with buffering problems. It means getting instant previews is not an option. The battery life is not the best either, The lack of a top LCD was a major worry at first although this soon fades. Could all these problems be down to a power issue with the super Foveon sensor? I am not sure, but it’s something that needs to be addressed. The Sigma is putting out 50-55MB files-most things in life do have a trade off and in this case it’s quality for speed.
The SIGMA SD1 is Sigma’s flagship digital SLR model
It’s pretty much the same story for the Pentax, but at a near $10,000 over-the-counter price, the Pentax is loaded with functions and toys. It has a shutter release, which shows you a low-resolution file for histogram and compositional reference aside from the normal shutter release. Dual memory card slots, GPS reprogrammable shooting modes, dynamic-range expansion (which works very well), super-large LCD and dust removal systems are among a few of its features. The 645D has the Hyper Program and Hyper Manual shooting modes that current Pentax users will enjoy using. However, my feelings are moved about the X-sync Flash mode.
The Pentax is every bit the camera you expect it to be. However, the Sigma has one more feature worth a mention. With a very simple removal of the dust/ IR filter, the Sigma is configured in to an infrared camera. This makes the SD1 Merrill a hot swappable 45-megapixel IR/visible light camera, and the new $3,000 price tag makes it look even more attractive. Sigma is once again leading innovation.
Both cameras deal with lateral chromatic aberration in a stunning way. The newer range of fluorite glass lenses from Sigma are also a nice progression for the company and the Pentax options are razor sharp, as we have come to expect from this brand.
Special features on board
Sigma SD1 Merrill: 8/10: a camera with innovation at its heart, although it lacks pedigree
Pentax 645D: 9/10: Pentax says ‘As a serious tool, the 645D is second to none’ – they are not far wrong.
Quality of image results & Examples
Sigma –
(Edit- http://www.davepiper.org.uk/blog/sigma-sd1-m – Sigma DKP gallery)
Sigma SD1 Merrill: 7/10: Fantastic results when used with patience and controlled in the right way
Pentax:
Pentax 645D: 9/10: Stunning results and $24,000 cheaper than a Hasselblad H4D-50
Image Quality:
Both of these cameras offer stunning results, but they achieve them in very different ways. The 645D uses raw power mixed with Pentax’s knowledge and imaging pedigree, where as Sigma is employing a dynamic approach with the new Foveon sensor. Each route has plus sides and downsides.
Both cameras are built with and uncompromising attitude to image quality. The Pentax is easier to work and live with by a clear margin, but both cameras offer up amazingly sharp, well-balanced images at around 50MB. The Sigma just needs a little more refinement when dealing with ends of the colour range.
The Sigma does have more of a tendency to blow it’s highlights, but when printed, the files are indistinguishable from which camera they came from. However, the Sigma is near $9,000 cheaper – you can buy an SD1 Merrill and a Jaguar X-Type 2.5V6 Sport, or you can by the Pentax 645D. However, some could say the Pentax is cheap-how much is a Hasselblad H4D with a 50MB back?
Using the Sigma SD1 Merrill does require a new workflow due to the X3F not being supported by Adobe just yet. The Pentax rival outputs to Adobe’s DNG file format. It’s very easy to see why the 645D won then EISA Professional Camera of the Year!
When are you talking about cameras in this sector of the market, you should only be thinking about quality. The truth is for a price tag of less than $3,000, the Sigma SD1 Merrill gets some major bonus point. Yes it is slow, the battery life is not great and the LCD screen is not the best, but ask yourself what you’re really paying for? In a studio, I would be happy to use either, and so would my clients.
(Edit- http://www.davepiper.org.uk/blog/sigma-sd1-m – Sigma DKP gallery)
