Prior to the RS, the EOS RT (a variant of the 650) offered a pellicle
mirror, semi-silvered so that it could remain fixed and provide a viewing
image while allowing most the light to reach the film.
As Canon found with their original 1965 Pellix, developed from the Canonflex RM2000 at the same time as the FT, the silence of the pellicle mirror SLR does not appear to outweigh the largely imaginary loss of image quality which the average buyer thinks such an obstruction must cause. The EOS RT was another dead-end development even though bodies are now much in demand, as often happens with a discontinued model offering a unique feature.
There remains a need at the very top end of press, sports, military, surveillance and scientific photography for shooting speeds with approach movie rates, combined with the size and convenience of a 35mm SLR. The critical frames per second zone is around 10fps, twice the speed of motordrives built in to cameras like the Minolta 9xi (still the fastest integral drive in a standard body) and three times the speed which qualifies for description as 'motor-drive' rather than 'auto winder'.
The Nikon Titan HS ran as fast as 14fps, but in practice it's not necessary to go to this extreme; when this kind of rate is demanded, 35mm movie cameras do a far better job, shooting at settings from 16 to 32fps and using a rotating prism to maintain TTL viewing. Specialist high-speed cameras, based on motion picture technology, can achieve rates many times faster than this.
The motor also provides 15% faster rewind times, and the absence of the moving mirror reduces the delay between pressing the shutter and getting a shot from 55 milliseconds to only 6ms. This comparison is quoted rather differently by Canon Ð they refer to the 6ms time, and separately to a 49ms reduction in shutter firing delay.
Perhaps this is because the idea that the existing HS model has a 55ms delay between triggering and actual exposure Ð a full 1/20th of a second Ð will come as a surprise to those who do not know just how very slow almost all AF SLRs are in this department.
Whatever the case, 6ms is as good as no time-lag whatsoever, and is not significant when compared to the eye-brain-finger delay involved in single shot work. At 10fps, or even the 6fps 'A' mode also offered by the EOS 1n RS, a 6ms delay at the start of a sequence is infinitely less significant than the 100ms gap between frames.
The pellicle mirror does mean a 2/3rds of a stop light loss at the film plane, but an improved non-user-changeable focusing screen designed to prevent fogging ensures that no perceptible finder brightness is lost.
This light loss might normally have a number of disadvantages such as inaccuracies when using a hand meter or non-TTL flash as the prism ' steals' 35% of the light every time. In practice it is hard to imagine the type of photographer who would require the RS using non-dedicated flash, especially when the metering and flash systems are so advanced.
The metering system is highly sophisticated Ð arguably overly so. Firstly there is a 16 segment evaluative pattern which also considers information from the five point autofocus system. Partial Metering (there is no centre weighted option as it has been rendered obsolete by the evaluative option) uses information from the central 9% of the image area. Fine Spot Metering uses a tight 2.3% circle marked in the viewfinder but it doesn't even end there. A custom function allows spot metering over a larger 3.5% area to be moved round the screen to any of the five user selectable focus points.
However it is reasonable to suggest that it would be as simple to use the central option, lock and recompose. But at least all the options are there.
The contrast between this and a camera like the Minolta 9xi can not be over-emphasized; on paper, the 9xi still outperforms the EOS when tracking moving subjects on AF, but does so in a way which seems noisy, jerky and disruptive compared to the whisper-quiet ultrasonic focus adjustment of the Canon.
Combine this AF action which no subject would normally hear, the very quiet motor-wind, and a shutter action no louder than a Leica M, and you have a camera which could be used at critical moments during public ceremonies or performances.
You might even avoid the abuse reserved for photographers from TV crews and still get to shoot action sequences. There are many situations where the sale of broadcast rights to TV stations gives them the ability to ban flashguns outright and have any noisy still photographers ejected. The EOS 1n RS could be a worthwhile extra £1,000 spent over the standard EOS 1n if you encounter this situation when working.
There are limitations to the RS model. For a start, we asked the owner of the rare RS which we had a look at, sports photographer Geoff Evans, to let us have a sequence to demonstrate it at 10fps. A month later, the winter weather still hadn't produced a bright enough day for the RS mode to be used as the 10 fps rate needs a minimum shutter speed of 1/1,000th.
Geoff's previous camera choice was a Nikon F4 and he was initially concerned at how well he would adapt to the handling of the Canon with its different weight distribution and thumbwheel controls. He needn't have worried as the camera turns out to be a delight to handle. When shooting in horizontally it fits the hand perfectly. Held vertically, Geoff found it more comfortable than we did, but then everyone's hands are different.
The built-in booster makes it quite bottom heavy but this seems to help control stability and balance, especially when panning.
The big control wheel on the camera back may look like a silly idea but it works better than you could ever imagine Ð in any case it can be switched off and on as required. The front control wheel would be more comfortable if slightly angled but works well enough. Functions are all easily activated with a bare minimum of buttons.
Although weighing in at a hefty 1.3 Kg Ð without batteries or lens Ð it seems to almost float in the hands, even if it might feel more like a brick in 'round the neck' mode. This makes it just a touch heavier than its nearest rival the Nikon F4s (5.7 fps) and exactly twice the weight of the Pentax Z1-p (4 fps) tested last month.
The drive booster is part of the camera unlike the rest of the EOS 1n range where it can be detached to save space or weight. Any of the other 1n models can interchange battery packs and boosters but the RS is stuck with its lot.
In the high speed RS mode is that the lens stops down to working aperture Ð dimming the viewfinder image as if back to stop down metering days Ð and the predictive AI autofocus tracking doesn't work at speeds faster than 5fps. 10 fps has its cost Ð both financially and in restricted features Ð but then you don't get anything for nothing.
Normally, the photographer will use the RS much like an EOS RT, but with EOS 1n drive speeds. In one-shot AF mode, you can fire 3 or 6 frames a second; in AI Servo mode, tracking the subject by updating the AF setting between frames, 2.5 or 5fps. To get the benefit of the silent rewind mode you must put up with 20 seconds to roll back a 36 exposure film, compared to only 7 seconds in velvet-burning mode. Having said that, orchestral performances and chess tournaments don't often call for lightning rewinds.
It may not have the other attributes we have associated with this kind of firing speed in the past, like a titanium body and a battery pack you wear in your underpants in cold weather, but it benefits from being a variant of a top-selling SLR for professional action sports and press work.
If you baulk at the price of the RS or are happy with 6 fps and a normal instant return mirror then the EOS 1n HS is more likely to be the model for you. Thanks to Geoff for bringing the EOS 1n RS into the office for a look over and a chat about its qualities as this is not a camera we expect to see in every dealer or be available for a routine test. No special prize to the first reader to spot one in use, either, but watch the sidelines of TV sports programmes and news events for glimpses of lenshounds desperately trying to load a fresh roll of film every 15 secondsÉ
DK/AA