Full frame image of a clear blue sky.
Is it a bird? Is it a plane? No; it’s a bit of muck on the sensor!
Cropped image, with sensor dirt arrowed
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by TRA Wouldn’t it be better to use a digital camera?
That is a question that only you can answer, as it depends on your imaging requirements and your budget. However, here is some information to consider when making a decision. There are at least ten key factors:
There are also other factors, such as the enjoyment you may derive from using one system or the other, being able to control the output, and the time that you have available. Shutter delay My limited experience with friends’ digital cameras (“Here. You take the pictures for me; your pictures always come out so well!”) is one of constant frustration because of the delay between pressing the shutter and the camera deciding to take the picture. With people shots (or any action shots), the precise moment is crucial. If the camera fires even one second later, the image is probably not worth having, as gestures and candid expressions can be so fleeting. Time was when all digital cameras seemed to have a delay of up to 2 or 3 seconds, which is really quite unacceptable. Many of the newer models are much better, but there is still the delay introduced by autofocus (OK, you can have that problem with film cameras, too, but why use auto-focus lenses?!). In my opinion, digital hasn’t yet reached the point where you can even be sure of capturing good candids of the children – though you will know quickly that you didn’t get the shot that you wanted! Image Quality If you must have ultimate image quality and the ability to make massive enlargements, using film as the originating medium is still the way to go (at the time of writing!) You may choose (like me) to shoot film, but print digitally. If you scan in a “6×6” negative (actually 56mm × 56mm) at 4800 dpi, you will get a file that is 10,488 pixels × 10,488 pixels. This results in a 629.4MB image – about one hundred times the resolution of most current digital SLR files!
The focal length multiplier effect Also bear in mind that even Medium Format sensors are not “Full Frame”: instead of a 56mm×56mm image you get something that is at most 48mm×48mm, and with many Medium Format backs substantially less than this. This has an impact on all the lenses that you use, effectively making them appear to have a longer focal length. This is especially a problem with wide angle lenses, where a 40mm ultra wide angle may provide coverage on a digital sensor equivalent to a 55 or 60mm lens on a full 56mm×56mm film frame – and in most cases with Medium Format equipment you will not find a wider angle lens available to give you the angle of view that you were expecting. This is in particular a problem for shots of interiors, but can also be a problem for landscapes and other types of photography. Speed of turn-round Digital images give you of course an almost-instant turn-round, though it is not quite as instant as you think. It does take time to
A digital back for a Medium Format camera such as the Hasselblad would currently cost you in the region of US$20,000, and even with this the image quality would be way below what you can achieve by shooting film in a Pentacon Six and then scanning it into your computer. Using the mixed film/digital route is not a zero cost alternative, but you probably already have a computer and a printer. A digital camera – even a 35mm one – may give you the quality that you need, but that won’t be in the same league as what you can get with film. And even a 35mm digital SLR with a full-sized sensor will also cost you a lot more than a Pentacon Six. Who is in control? and What is the frustration factor? A neighbour and good friend of mine has enthused about his new digital camera, and has insisted that I try it out. Naturally, I was delighted to do this. It is the latest model of one of the top-name digital compacts, with a 10 point something megapixel sensor and an 18× optical zoom. I have taken a series of pictures in my studio with it, and here are my conclusions: 1) It is capable of some good results, so long as the image is not displayed or printed too large, and subject to the other factors indicated below. 2) Getting the right framing is difficult because:
4) Because of the tiny sensor and the extremely short focal length that is consequently necessary for the lens, differential focus is impossible. For instance, in a portrait, the background will be as sharp as the face, which is usually the opposite of what is desirable. 5) The manual says that at some settings, “straight lines near the edge of the image may appear curved, or unexpected colours may appear. This is not a fault”!! Well, that’s what experienced photographers call barrel distortion, pin-cushion distortion and chromatic aberrations or colour fringeing! 6) Down-loading the pictures to the computer and converting them from raw is complicated and tedious – no batch conversion from raw is available, and following the on-screen instructions generates error messages. There are work-arounds, but they do not appear to be documented. Doing this processing is definitely not an enjoyable experience. 7) The main difference between this up-market state-of-the-art digital camera and a Pentacon Six is that with the Pentacon Six the photographer is in control and can easily control framing, shutter speed, aperture, focus, depth of field/differential focus and other factors that are crucial to the final image. Of course, the Pentacon Six is bigger and heavier, and you have to wait until the film is processed to see your results. But what counts ultimately is the quality of the image. And here, the Pentacon Six wins hands down. Conclusion: Not only do I enjoy the results I get from the Pentacon Six, I also enjoy the process of using it. Neither could be said of my experience with this expensive digital camera, so why use it? Sensor dirt For the flexibility and quality that you seek, if you do buy a digital camera, you will probably want a “DSLR” – a digital Single Lens Reflex. After all, only an SLR will enable you to change lenses, see and meter through the lens and build up a system that will enable you to go from extreme wide-angle to powerful telephoto, not to mention tilt, shift and macro work. But after you have bought your DSLR you will discover a new problem: dust on the sensor. No matter how carefully you change lenses, dust – and sometimes remarkably large bits of fluff and muck – will get into the throat of your camera, and when they are there, the electrical charge on the sensor will draw that dust, fluff and muck onto the delicate and highly-expensive sensor, where it will stick! You can dust the rear of the lens before putting it on, point the camera downwards while changing the lens, only change lenses indoors – or anything else! – but sooner or later, dirt will settle on your sensor! Some experts explain that the action of changing the focal length of some digital zoom lenses acts like a powerful pump to pull dust into the lens and from there into the camera. If (sticky!) pollen gets onto the sensor, getting it off is going to be a big problem. Like me, you may never have experienced this problem with a film camera, but with a digital SLR it will appear. Worse, you are unlikely to see the dust, muck and fluff when you view the images on the camera’s screen; you will first see it on all your pictures from a given session, once you have downloaded them onto your computer. Then you can have many happy hours, trying to clone them out! Why haven’t you had this problem with film SLRs? Well, each time you advance the film, you effectively get a brand new “sensor” for the next image! Of course, if your camera has dust in it, this can scratch the film, but:
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Full frame image of a clear blue sky. Is it a bird? Is it a plane? No; it’s a bit of muck on the sensor! |
Cropped image, with sensor dirt arrowed |
In these two images, the dirt can be cloned out, but in other images
where it was on a person’s face or other area of detail, correcting the
damage was time-consuming, difficult and sometimes not entirely satisfactory.
Don’t be surprised if each time you fire the shutter on your digital SLR
you find yourself asking, “Will this picture be spoilt by muck on the sensor?”
| Dead Pixels
I am grateful to a visitor to this website for
bringing this to my attention (in February 2011). He writes:
As indicated above with regard to dirt on the sensor, dead pixels will affect every picture. I could say that a film fault would only affect one image - but I don’t remember ever experiencing such a film fault, in decades of photography. Not surprisingly, this visitor has recently bought a Pentacon Six and a range of lenses. Viewfinder Perhaps up to a third of digital cameras by model have a viewfinder, but by number of cameras sold - if we are to judge by observation of people taking pictures in public places - over 90% do not have a viewfinder. “So what? Why do you need a viewfinder?” you may ask. Here are a few reasons. No doubt you will be able to think of more. Composition
Visibility of the image
Focussing your eyes
The camera with the separate viewfinder has a couple of
advantages and a couple of problems:
The digital SLR (Single-Lens Reflex) has all the advantages of SLR cameras. It has a viewfinder that looks through the lens and enables you to check composition, focus etc. Many of these are great cameras, but have you noticed a couple of things?
One of the superb advantages of Medium Format cameras is the possibility of differential focus. This means concentrating the attention of the viewer on that part of the image selected by the photographer as the intended focus of attention, by skillfully throwing other parts of the image out of focus. To achieve this, the lens needs to combine two characteristics:
The problem is this:
So, you could solve all these problems by going out and buying a medium format digital camera. But have you seen the price of a Hasselblad H4D lately? I can see one “on offer” right now for GBP27,666.00 - not including a lens! Or you could buy a Pentacon Six - with most of the lenses you could ever need or want - for less than a tenth of this price! The move “back” to film We might speak of a move “back” to film - but there is a whole new generation of young photographers who have never used film, who are now discovering the joys and advantages of this medium. Even on a digital photo forum I have seen in recent days requests for information on how to process film, and the suppliers are still out there, selling chemicals, thermometers, developing tanks, etc. Alternatively, of course, you can do what the majority of photographers have done for more than a century: shoot film and let a lab do the processing. Pentacon Six and digital! So perhaps you should go for a Pentacon Six and digital. This could be the best way forward. Please see the next page. |
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© TRA November 2005, August 2011