Thursday, 15 December 2011

Fujifilm IS Pro UV-IR DSLR review


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Fuji’s IS Pro is the up-date to maker’s earlier S3 UV-IR camera, and like that particular camera, the IS Pro adopts a modified image sensor that’s not shielded from UV or IR light. Consequently, with various filtration methods, the IS Pro is designed for Ultraviolet (UVA), visible and near Infrared photography.

Although there is a healthy demand for DSLRs with IR capability especially, and there are number of independent vendors (mainly in the US, but the UK also) that offer IR dedicated and full-spectrum conversion of current Nikon and Canon bodies, it’s anticipated the IS Pro will appeal largely to the scientific and forensic communities. With the departure of the S3 UV-IR, Fuji’s IS Pro continues to be the only dedicated full-spectrum interchangeable lens based DSLR that has professional-level support from a camera maker. As well as official product support and 12-month warranty, for government agencies and the like, the OEM status of the IS Pro will be particularly reassuring and attractive. What’s more, I would imagine photographic evidence acquired using the IS Pro is less likely to be questioned than unofficially adapted cameras.

Neither Canon nor Nikon offer UV-IR modified DSLRs, however the former developed an IR modified EOS 20D, the 8.2-megapixel Canon EOS 20Da. This adopted a modified IR bandpass filter solely for Astro-photography in the 656nm bandwidth. Interestingly the EOS 20Da allowed Live View from a firmware modification but it’s now no longer available. Besides it’s not just the exclusivity of Fuji’s purpose designed offering, as another consideration must be the availability of a number of quartz glass UV lenses made in Nikon F mount.

Modern multi-coated lenses are more effective at reducing the transmission of UV than older single-coated lenses, but they still allow a substantial amount through, hence the need for blocking filters where high levels of UV light is present. With the inherent sensitivity of both UV and IR of CCD’s and CMOS-based imagers modern DSLRs also feature a strong IR cut filter in front of the sensor. Without an effective IR blocking glass, infrared contamination can lead to some image softness and a magenta colour cast that’s impossible to completely correct in post-production.

Early Nikon DSLRs were often criticised for this, and especially when used with flashguns which are known as high emitters of infrared light. More recently, Leica’s M8 rangefinder is similarly noted for the adoption of a weak IR blocking glass, leading the maker to recommend additional lens filtration.

Body and Ergonomics


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Just as S3 UV-IR camera was converted from the maker’s S3 Pro DSLR, the IS Pro is built from Fuji’s popular S5 Pro body. This in turn is based on the Nikon D200, which after being shipped in component form from that maker’s factory in Thailand, is married to Fuji’s excellent SuperCCD sensor and assembled by them in Japan. The maker is said to have converted five-hundred S3 Pro cameras previously, and with the discontinuation of the D200, we can assume a similar number of S5 Pro bodies have had the same treatment.

Fuji claims the IS Pro’s modified imaging sensor captures wavelengths ranging from 380nm to just below 1000nm, encompassing UV (A) to near Infrared. Information isn’t readily available from makers concerning the spectral transmission of their sensor’s cover glass, but it must be close to that of human vision, roughly 400-700nm. On that basis we can see the IS Pro is particularly suited to IR photography.

Essentially, the IS Pro is a Fuji S5 Pro that has had the IR blocking filter removed from the sensor and replaced with what the maker calls a special glass filter. We’re not told what’s special about it but it’s likely to be made of quartz glass and its inclusion is essential to retain auto-focus accuracy in visible light while providing some protection during routine cleaning and maintenance. Like other converted full spectrum DSLRs, the IS Pro cannot use the built-in AF module to focus manually or automatically on objects illuminated solely by either UV or IR light. However, a key feature is the IS Pro’s Live View option which can be used to assess focus with optional UV and IR bandpass filters in place.

Apart from that, the only other stated difference between the two models is the IS Pro’s firmware has been modified. Again, we are not told what this means other than 'it’s fully activated to engage the cameras UV, Visible, and IR abilities…and no other firmware modifications are necessary’. The IS Pro’s menu, and instruction manual mimic’s that of the S5 Pro. None of the advanced features such as Fine-Tune Exposure, Auto-ISO, Film Simulation modes or D-Range options or support for GPS geo-tagging have been omitted.

Although the maker’s S5 Pro has been reviewed previously in this magazine*, it’s worth re-counting the benefits as well as some of the shortcomings with regard to the IS Pro. Fuji’s proprietary Super CCD was generally regarded as having superior high-ISO performance over the D200 at the time, and it was lauded for its wider dynamic range – a result of the dual-sized SR pixel pairing. As noise levels are inherently higher with both UV and IR photography, effective Noise Reduction is a particularly attractive feature. On the downside, although output is 12.3 megapixels at its maximum, fine detail and resolving power in general was lower due to the intriguing interpolation system. What’s more file sizes, especially as uncompressed Raw (RAF) files using the W2 (400-percent D-Range) setting were quite large by comparison, often in the region of 25MB a file.

The IS Pro, like the D200 adopts a low-dust producing shutter mechanism but it lacks the auto sensor cleaning systems found on the latest DSLRs. And despite only having several-hundred shutter activations images from our sample revealed plenty of dust spots. Unlike the Nikon D200 that requires the AC adaptor to be attached for sensor cleaning, the IS Pro has a more user-friendly cleaning procedure providing the battery is full charged. An electronic beep and flashing AF illuminator warn of lessening power, which is a nice touch, but for cleaning of stubborn particles and prolonged use of the Live View feature you’ll need the security of the AC-adaptor.

Viewfinder

A Nikon eyepiece adaptor (DK-21M) with a 1.2x magnification is available that improves the fit to the eye but darkens the corners of the frame slightly. It’s a great help for manual focusing, though the viewfinder of IS Pro isn’t likely to be used often. Although it’s just possible to view a brightly lit subject through one of the dark-red IR bandpass filters, it’s almost impossible to focus using the optical viewfinder with any accuracy. A hinged gelatine filter like the type used for film would seem like a good workaround; focusing in the visible spectrum, locking the focus, then flipping the filter back into the light path while compensating for the shift in focus with IR.

Fuji suggest experimenting with the older manual focus Nikkor lenses for their older coatings. We must assume they mean older lenses with single coatings. The majority of AI and AI-S lenses adopt multi-layer Nikon Integrated Coatings (NIC), though it’s likely the newer AF lenses using Nikon’s Super Integrated Coatings (SIC) are even more efficient at blocking UV.

That said, older manual focus AiS lenses feature the now largely missing IR offset for more precise focusing. Sadly, these have been mostly discontinued and are becoming more difficult to find new. Judging the shift in focus required for UV isn’t as simple, but that’s where Live View scores so highly. Although pricey, a purpose-designed UV lens is recommended. Made from quartz glass, UV lenses boast high UV transmission rates usually in excess of 70-percent and have little or no focus shift. Fortunately, makers such Coastal Optics in the USA and a Nikon industrial subsidiary, Tochigi-Nikon, make quartz lenses in Nikon F mount which are well suited to the IS Pro.

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My IS Pro sample was supplied with the rather luxurious Carl Zeiss Makro-Planar 50mm f/2, but not for my benefit I suspect, but rather for its unprecedented maximum aperture. It’s worth noting the Zeiss lens isn’t a true macro lens as it only goes to 1:2 but Nikon’s PN-11 extension tube will easily take the reproduction ratio to life-size. The 50mm Zeiss is the lens of choice for several of the bundles I’ve seen advertised, but I also managed track down Tochigi-Nikon’s successor to the legendary manual focus Nikon 105mm f/4.5 UV-Nikkor.

Live View

Although often overlooked now the S5 Pro was the first DSLR to offer an effective Live View option in full colour, as well as mono. This wasn’t a feature of the 10-megapixel D200 despite much of the S5 Pro’s firmware source code being written by Nikon. However, this ability to focus accurately using the camera’s imager is a crucial advantage over earlier UV/IR compatible offerings.

Sadly, selecting Live View is at least a two-button operation. You have to press and hold what was the Face-Zoom in button on the S5 Pro for two-seconds, choose between the B&W or Colour options (each time, as it’s not memorised) then press the Menu/OK button to confirm. Unfortunately, the IS Pro like the S5 can only provide a Live View image for 30 seconds, to prevent overheating of the sensor. And, somewhat annoyingly the on-screen second-by-second count down only serves to heighten anxiety, in my view. An option to switch that off would be handy. What’s more, the shutter can’t be released during Live View, making the whole procedure far from slick. Naturally battery power suffers considerably, making the optional power adaptor a must for prolonged use.

On the plus side, Fuji’s SuperCCD, like other CCD’s, is highly sensitive to IR and when using the IS Pro’s Live View feature in daylight images can still be focused and used hand-held with the opaque, nearly black-looking Peca 900 UV+IR (18a) and B+W 093 IR bandpass filters. You have to adjust the screen’s brightness to the maximum, a simple operation using the camera’s cursor key, and you can also magnify the image for improved focus accuracy with the same control-pad. The option to display either in colour or black and white is sensible, as I found focusing slightly easier as a result of the increased contrast when set to the latter. While the 2.5-inch 230k dot screen is small compared to the latest DSLR offerings the Live View is what elevates the IS Pro over older converted rivals.

Adopting Live View in low light, using the relatively fast Carl Zeiss Makro-Planar 50mm f/2 (extremely fast for a macro lens) with the dark red B+W 092 (Wratten 87b) IR filter was much more difficult due, in part, to some poor gain control of the LCD. With the slower maximum aperture of f/4.5, unsurprisingly, the Nikon Rayfact 105mm UV lens with any of the opaque filters attached is practically impossible to focus accurately with. If you intend to light by flash, for example, this need not be a show-stopper but you will need a workaround. Using a continuous light source could be an alternative but in the case of UV, precautions would have to be taken to limit the harmful effects of inadvertent exposure.

Metering and Exposure

The Carl Zeiss ZF lenses are built to the AI-S specification that’s to say they lack electronic contacts and internal CPU unlike Nikon’s AiP or AF lens range. Even so the IS Pro will colour matrix meter with manual focus lenses providing the focal length and maximum aperture are entered beforehand. Set-up using the menu is a bit clunky but selecting the relevant lens can made a shortcut using the front FN button. Despite that, the IS Pro tends to overexpose backlit scenes especially when using the B+W 092 (87b) and will easily underexpose at other times. Although difficult to find, separate RGB histograms are provided in playback only, but are genuinely helpful when determining exposure.

With the combination of low UV light levels and the Peca 900 (18a) filter attached from the sample of photos shown the exposure was some 6 stops longer than the unfiltered image. Even accounting for the IS Pro’s increased infrared sensitivity, with the opaque B+ W 093 filter attached the exposure was still some 4 stops longer than the unfiltered sample photo. So although there may be a opportunity to use the IS Pro handheld occasionally, for other times where maximum depth of field (and focus accuracy) is a must a tripod will have to be used.

Software and Image Quality





I’m lukewarm with regard to the supplied software – Hyper Utility HS-V2 version 3.1j for Windows and Mac. HS-V2 has been the subject for discussion in an earlier issue of the magazine, so I won’t elaborate other than to say it’s pretty clunky in use and the layout would benefit from an overhaul. Neither was the supplied software compatible with the latest Mac OS, version 10.5. Be that as it may it offers tethered operation of the IS Pro (not with Live View), which is an obvious attraction in a studio or lab, and produces the best quality files with the lowest possible shadow noise from Raw. As it emulates the in-camera processing it can also be used to reproduce the film simulation modes from Raw, should you decide to use the IS Pro for visible light photography. However, I found the B+W UV/IR cut filter (486) doesn’t block enough IR light, leading to a slight magenta cast. Besides, until recently with the release of ACR 4.6, it was the only solution for developing the IS Pro’s Raw files.

Adjusting the white-balance can produce very strong and unexpected colour shifts that can be quite desirable aesthetically but if shooting raw files this can be wholly ignored. With the increase in exposure times, so we are likely to see an increase in noise. Noise levels are low even at ISO 400, and still well controlled up to ISO1600. At ISO3200, luminance noise is quite high and detail suffers but this is unlikely to be an issue for the majority of targeted users. Similarly, with the only real downside being an increase in file size and processing demands, the IS Pro’s impressive expanded dynamic range option is an advantage when it’s needed. Output from the IS Pro looks both flat and a little soft as a result and neither in-camera Jpeg’s or Jpeg’s from Raw files sharpen that well. This may well be due to the inclusion of strong AA filter as both the Carl Zeiss and Nikon 105mm UV lenses deliver impressive sharpness on an APS-C crop camera, such as the D200. Still there’s no questioning the enormous gain in exposure latitude with Raw files from the Fuji.

Conclusions

While the IS Pro may no longer be at the cutting edge of DSLR design the Live View feature has enormous advantages, especially when used with a strong and continuous light source. Even if Fuji could adopt the newer D300 or D700 body, fitting opaque filters on the lens thereby obscuring the viewfinder and image sensor is a shortcoming for handheld use. However there are several workarounds to this and when used on a tripod the IS Pro works well.

With an effective Live View system, pro-level build, low noise and impressive dynamic range the IS Pro is a huge step over its predecessor, the S3 UV-IR. System compatibility aside, landscape and fine art photographers would find the IS Pro attractive, though there could be an argument for a dedicated IR camera which would retain normal viewfinder focus operation. For the scientific and forensic communities, however, the OEM status and official support makes the IS Pro a compelling choice over an independently modified DSLR.



*This review was originally written in December 2008, however the camera has not been updated in that time and is still available, albeit in limited quantities.

Contact


For more information on the IS Pro visit Fuji at www.fuji.co.uk, or www.fujifilmusa.com

For information regarding the outstanding Nikon UV-105mm f/4.5 visit www.invisiblevision.com

Carl Zeiss lenses are distributed in the UK by Robert White, www.robertwhite.co.uk

B+W Filters are distributed in the UK by DayMen International, www.daymen.co.uk

Peca Filters are distributed in the UK by Bob Rigby, www.bobrigby.com

Sales


Adorama currently have a special promotion on the Fuji IS Pro here (was $799.95, now $599.95). Buy Carl Zeiss lenses from Adorama.

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