About Telecine (film to TV) Transfers!
Not all telecine services are created equal. Indeed the spectrum
of possibilities is a continuum from the very poor to the very good,
with price by no means a good indicator of quality. This page is
about giving you an idea of the range of options out there, how
they differ, and enought information to understand where Nano Lab's
service fits in the scheme of things. If you don't need this introduction,
jump straight to our telecine service
page for details of what Nano Lab offers. On this page:
DIY transfer tips
Continuous motion scanners
Output Media: The third man in transfer quality!
Best possible Super 8 transfer?
determine the quality of a telecine offering: the equipment, the
operator and the output media. Of the three, the operator is the
wild card and perhaps the most important though least under your
control. The best equipment, used by a bad operator gives bad results.
Only experience (yours, or preferably other people's) will determine
if the person doing the transfers cares about what they are doing.
If they left a hair in the gate, chose the wrong exposure, left
the image out of focus or poorly coloured, or with the frame line
showing, or over cropped, etc., etc., well that's it. End of story.
So let's talk
about equipment instead!
I'd like to
divide the range of possible transfer set ups into three categories:
real time, frame-by-frame and continuous-motion (flying spot scan).
A 'real time'
transfer involves a projector operating at or near normal projection
speed and a camera recording the projector's image at the normal
TV rate of 25 frames per second (PAL). The classic telecine-chain
(projector, condenser lens and camera) is an instance of this. So
too is the basic 'off the wall' transfer or similar methods involving
rear-projection screens, transfer 'boxes', mirrors, gadgets and
widgets. There are also little 'all in one' transfer units that
are basically a projector with a single chip ccd pick up where the
lens would be (this is a very common method of transfer out there,
so be warned!).
The basic feature of the real time transfer is is a non-synchronous
coupling of projector and camera. What's wrong with that? A little
bit of theory will help here. Movies are generally filmed using
a framing rate of 24 or 18 frames per second. That is, every second,
the projector flicks through 18 or 24 distinct still pictures, employing
a shutter inside the projector to block the light while the projector
intermittently advances from one frame to the next. TV on the other
hand uses a frame rate of 25 frames per second (at least PAL TV,
the standard used in Australia, does). Every 25th of a second, the
TV screen is electronically scanned in horizontal lines from top
to bottom in order to make an image on the screen. Indeed, it's
a little more complex than that again. Each frame of TV is itself
divided into two parts known as â€˜'fields'â€“
each lasting a 50th of a second. In the first 'field' all of the
odd numbered horizontal lines are scanned, then, in the second field,
returning to the top of the screen the even numbered horizontal
lines are scanned. These two fields, 'first' and 'second' or 'odd'
and 'even' are thus 'interlaced' to make up a whole frame of image.
There are two fields per frame, twenty-five frames per second, and
so fifty interlaced fields per second.
The trouble for real-time telecine is fitting the 18 or 24 frames
of film into these 25 frames or 50 fields of TV. They just don't
fit. If left to their own devices the result can be a strobing or
pulsing effect as the differing frame rates 'beat' against each
other. No good. There is a solution to this, however: change the
If the original film footage was shot at 24, the usual practice
is to speed the projector up to 25 fps â€“ the
same as TV. This is only a very slight increase in speed (though
it may play havoc with sound recorded with the film) and is better
than pulsing. This way, the result is one frame of TV for one frame
of film â€¦ almost (I'll get to the 'almost' later).
When the original film was shot at 18 fps, the best solution for
real-time telecine is to slow the projector down to 16 and two-thirds
frames per second. This seams an odd choice at first. On closer
inspection, however, its sense is clear: 16+2/3rds goes in to 50
exactly three times. Remembering that there are 50 fields per second
of TV, this means that there will be three fields corresponding
to each frame of film. Again this beats the pulsing devil (but with
the same 'almost' I alluded to above).
So why only 'almost'? Surely if the projector is running at 25fps
and the camera is running at 25 fps there will be one TV frame per
frame of film? The problem is that while the projector and the camera
are running at the same speed and thus advancing at the same rate,
they are nonetheless not synchronized together and nothing determines
that they will start each frame at the same time as each other.
If for instance the TV camera and the projector were a 50th of a
second out of synch with each other, then any one frame of film
will be captured by the second field of one TV frame and the first
field of the next, instead of two fields from the one TV frame.
A more normal case would be a random devision of each film frame
amongst a spread of TV fields: perhaps part of the first field of
one frame, all of the second field of that frame and part of the
first field of the next frame.
There are two consequences of this. Firstly, the overall effect
of a real time telecine done this non-synchronous way is a general
softening of the image â€“ some describe this nicely
as a slightly dreamy effect. Secondly, and more importantly, it
can make computer editing â€“ which is done by
the frame, not the field â€“ very difficult.
Another factor to consider with real time telecine transfer is the
general quality of the optical system involved. Generally a real-time
transfer will involve two lenses â€“ one on the
projector and one on the camera. Often these will be zoom lenses
meaning even more glass. Both of these lenses have to be perfectly
focused. Further, there needs to be some intermediary element. In
a classic telecine chain set up, that intermediary is a large condenser
lens. In other setups there is a screen, a piece of plastic or some
such other device. This third element also has its optical properties
and leave its mark on the resultant footage â€“
be it in the form of its grain or texture or other optical abberation.
A real time transfer can be quite good, especially when done using
a classic telecine chain set up with an experienced operator. This
is not the norm howerver. By far the majority of film to video transfer
businesses use straight 'off the wall' or other low tech systems.
Such systems almost always feature a pronounced 'hot spot' in the
centre of the image where the projected light is brightest. Be warned.
Ask to see a sample before you commit any money!
DIY OTW (off the wall!) transfer tips:
Still, I can
give some tips here to those who want to do an off the wall type
1) Make the
projected image as small as possible. This may be determined by
how small a projected image the camera can focus on, etc., but the
smaller the projected image, the greater the contrast range and
the colour saturation, so keep it small. The small image also helps
reduce the potential hot spot from the lens.
to have the camera as square to the projector screen as possible.
3) It may be
a good idea to put a small doughnut of cardboard right in front
of the projector lens. This will act like an apeture and effectively
stop down the projector lens and thus increase the depth of field
of the projected image. This can help with getting edge-to-edge
focus of the picture.
This is a relatively
new approach for film to TV transfer. Indeed it is a product of
the digital age and is better described as film to digital transfer.
The basic set up involves a film transporting device with an intermittent
motion (just like a projector), a digital or digitized camera, a
computer with appropriate capture software, and a triggering device.
The film is advanced a frame at a time at a fairly slow framing
rate of between say 3 and 8 fps. As each frame advances, the computer
is triggered to capture and store one frame (two fields) of image.
The film advances again and another frame is captured. And so it
goes. After completion, the software converts what is essentially
a series of still pictures of each frame of film into a digital
movie file. One frame of film now corresponds to one frame of digitized
data. It must be noted that due to the slow transfer speed, the
sound of sound films cannot be transfered using frame-by-frame technology.
For this a real-time transfer is necessary.
But what of footage shot at 18 or 24 fps? There are a few options
here. Either the computer can 'blend' some frames to make up the
missing 1 or 7 frames per second, it can simply duplicate 1 or 7
frames every second, or it can duplicate 2 or 14 fields every second.
The last option gives the smoothest conversion, but the second option
(whole frame duplication) is generally the preferred option as it
avoids a version of the 'field' problem we saw with editing real-time
It must be remembered that not all frame by frame systems use the
same equipment. The type of camera used is a significant ingredient
in the overall quality, as is the type and amount of optics used,
as well as the linkage of the camera's signal to the computer. One
common method of frame-by-frame transfer is to use a domestic digital
camera. This can yield quite adequate results, though it does mean
using the domestic camera's zoom lens, as well as a condenser lens
and the original projector lens, as well as being limited to a 'fire
wire' (which means DV compression) linkage to the computer. It is
also possible to use a broadcast quality camera with a special 'flat
field' macro lens mounted on the front. This then is pointed directly
at the film frame with no other optics in between. Such a camera
might allow for a component video (Y/C) output to the computer or
other non-compressed digital output, etc..
Frame by frame transfers are ideal for digitizing well exposed reversal
(ie positive camera original) film. With minimal processing of the
camera's signal it is possible to achieve a very good reproduction
of the original film image (again, provided it is well exposed in
the first place). They offer a cheap, very high quality transfer
option. Indeed the advent of the frame by frame scanning method
has been in part responsible for the renaisance of Super 8 in the
This technology, however, reaches its limit with transferring colour
negative film. For this, the last and most expensive category of
transfer equipment â€“ the continuous motion flying-spot
type scanner - is necessary.
Let me start
by pointing out that the heading for this category is something
I have made up! In the film and TV industry these machines are simply
refered to by their brand names â€“ Rank, Cintel,
etc.. But this term 'continuous-motion' makes for a neat categorization
in contrast to the other two above. Instead of the film advancing
a frame at a time, or in real time (via the intermittent motion
of a projector, its claw and shutter), the film is passed in a continuous
smooth motion over a single photosensitive array - a 'flying spot',
hence the conventional name 'flying spot scanner'. In the newer
CCD machines, this is a single line of ccd pickups one pixel wide.
With the older flying-spot machines, the pick up is a single beam
from a cathode ray photo tube moving back and forth in the horizontal
plane only. Division of the film back into frames is then achieved
electronically by the machine. Additional 'hybrid' frames are created
during transfer to compensate for the difference in frame rate between
the original film and TVs 25 fps rate.
The absense of the intermitent motion of conventional film projectors
means that these machines offer the steadiest possible transfer
of film to video. Image steadiness in film is really a product of
the precision of the mechanics involved in the intermittent transport
of the film through the camera, projector and or printer gates.
Most 35mm and many 16mm cameras minimise this tendency for image
unsteadiness by using 'pin registration' - literally 'pining' each
frame to the gate before the shutter opens and exposes the film.
Unfortunately not only are super 8 film frames very small, but there
are also no pin-registered super 8 cameras. This is why there is
an inevitable tendency towards image unsteadiness in super 8 film
(part of its 'lively' charm perhaps?). Suffice it to say, while
continuous motion transfer machines they do not ordinerily process
out any inherent image unsteadiness caused by the camera's intermitent
motion, they nonetheless do not add any image intability of their
own. In this way, continuous motion transfers will always be just
that bit more stable than any of the other projector based systems
These machines have been designed with the particularly difficult
task of transferring colour negative film to video. This is difficult
because of the nature of colour negative film, in particular its
so called 'orange bias'. This is not a separate layer or a base
colour, but part of the dye layers themselves - specifically of
the green and red sensitive layers. This bias was designed in to
colour negative film in order to overcome an inherent weakness in
colour dye technology â€“ namely producing an accurate
photographic dye for the red or a green sensitive layers. The answer
was to actually colour the red and green sensitive emulsions themselves
with a colour to compensate for the error in the dye. This colouring
of the emulsion remains where there was no developed dye image,
and is developed out in proportion where ever there is a developed
image. The result is an even colour cast across the whole developed
and undeveloped parts of the image. Reversal film, of course, uses
the same colour dye technology without having to have this bias.
Let us remember, however, that negative film was principally designed
for printing onto other film to make a positive â€“
sometimes through several stages of printing. This colour inaccuracy
would compound if the colour bias system was not used.
Continuous motion scanners then have been designed with the capacity
to not only invert the colours of colour negative film, but also
process out this orange bias. Further, negative film has a greatly
reduced contrast range in comparison to reversal film. Today we
might call this reduced contrast a form of 'compression'. This compression
has to be expanded out again in the processing by these machines.
As such, these machies incorporate very powerful colour correction
and image processing capabilities. This capability, essential for
colour negative, can also be very useful in salvaging badly under
or over exposed reversal film. Further, continuous motion scanners
usually also incorporate processing for reducing the appearance
of scratches and dust, as well as minimizing film grain.
To harness all this power, these machines need to be operated by
similarly gifted colourists. Further, the colourist must be given
time to work their magic on the footage. This is why these machines
are not only expensive to buy, but also expensive to operate â€“
a good result from these machines takes time, and this the customer
has to pay for. The quality of the transfer achieved will (assuming
the ability of the operator) be directly proportional to the amount
of suite time purchased by the customer. supervised by the client
and operated by a master colourist given ample time to manipulate
the footage. Conversely, a cheap transfer using one of these machines
may not be worth having.
In reality only this level of machine is relevant to the 35mm/16mm
film industry. The advent of Frame-by-Frame scanning has been a
revolution in Super 8 film making where very often price is an important
factor â€“ especially in independent films. Further,
the continuous-motion scanners require different film gates for
different film gauges. These gates are expensive to buy and take
time to change between and set up. Few transfer houses with these
machines see Super 8 as a relevant market slice for their business.
This may change.
Media: The third man in transfer quality!
You have to
choose an output media commensurate with your needs and desires.
You would be silly to spend thousands of dollars on flying spot
suite time in order to output to VHS or its contemporary equivalent,
the DVD. This being the digital age, your choices really come down
to the question of compression and what is called 'colour sampling'
or 'colour space'.
The bottom of the digital heap is the DVD. This has a compression
level of about 50:1. Through using Mpeg2 compression, it is possible
to fit up to 2 hours of program on one 4.7gig DVD disk. This is
a great format for distributing your film to interested parties,
or the video store, etc., but its no master, archival, origination
or exhibition format. Further, it must be remembered that files
stored on a burnt dvd are really only temporary. The disk will remain
readable for a few year â€¦ maybe five or so.
(Burnt disks are very different from mass produced 'stamped' disks.
These may last many many years).
Next level is MiniDV. The MiniDV format is really just the consumer
version of the DV format. Same tape, same compression, just a different
cassette. MiniDV has been a popular origination format for home
movies and some independent 'films'. It incorporates a 5:1 level
of compression and what is described as 4:2:0 for PAL or 4:1:1 for
NTSC colour sampling. This means that colours are 'sampled' at a
quarter of the rate to the image brightness. DV compression is itself
fairly costly to the original imput signal. DV compression too often
results in so called 'digital artifacts' when edited. MiniDV tapes
are themselves very flimsy and should not be considered an archival
or exhibition medium, though they ought to remain playable long
after the demise of similar age DVDs. The small and flimsy nature
of MiniDV tape can sometimes create problems when playing a tape
in a machine other than that it was recorded on. This is something
to be aware of with transfer where this is almost always the case.
Be prepared for tape failure if you are working to a tight time-line.
Digi Beata tape is really the first level in so called 'broadcast
quality' digital tape. It involves very minimal compression, and
colour sampling of 4:2:2 - twice that of DV. The tapes are themselves
fairly expensive, as is access to playing and editing equipment.
This is a good format choice for mastering, archiving and distributing
Beyond digi beata are various uncompressed digital tape formats
usually with 4:2:2 colour sampling. Sometimes this colour space
will record each pixel of colour information using 8 bits of data,
sometimes 10. This is very 'high-end' stuff and frequently beyond
the reach of the super 8 film maker. Having said that, it is sometimes
possible to get so called 'uncompressed', 'direct to hard drive'
digital transfers of your film. Sometimes this can involve posting
a portable hard-drive to the transfer facility, or else, purchasing
a drive from them directly. This is a way of getting your footage
in to your computer for editing without the expense of digi beta
or the losses involved with lesser tape formats. As it happens,
Nano Lab offers a variation on this theme for the super 8 film maker:
namely transfer to uncompressed data DVD disk. This is a normal
4.7 gig DVD disk, but not recorded using DVD mpeg 2 compression.
Instead, no compression is used and this is a data file only. One
50' roll of super 8 takes up 3 or 4 gig of disk space. (For more
information about Nano Labâ€™s telecine service,
see our 'telecine transfer' page). It needs to be pointed out that
computers, drives and disks can be fraught with all sorts of protocol
and compatibility issues. Hard drives can 'die', disks can be 'duds',
file types can be wrong for your system, etc.. A DVD disk costs
about a two-hundredth of the cost of a digi-beata tape and cannot
be expected to be as reliable. Again, if time is short, be prepared
for these sorts of issues!
So back to the
With all transfers,
the operator is a critical ingredient â€“ especially
with the continuous motion transfer with its powerful image processing
capabilities and hence requirements. With the cheapest transfers,
the machine might be set up and left unsupervised. This can be called
a 'one light' transfer â€“ that is, no adjustments
are made to the transfer image in response to changes in the original
Another unsupervised option, again very easy for the operator, is
to use an automatic iris on the camera or pick up. This means that
as the original film scene gets dark, the iris of the pick up camera
compensates by opening up, and vice versa with bright scenes. With
frame-by-frame transfers this can be a problem in that the camera
iris can change in response to very fleeting changes in brightness
of the original film â€“ such as when a white car
quickly crosses the frame. The result is a sudden darkening of the
image as the car passes. Also, a 'fade to black' in the original
film will be transferred as a 'fade to gray' as the iris progressively
compensates for the darkening film image. Still, an automatic iris
transfer can be a good option for home movies that might not otherwise
warrant a closely supervised, slower and thus more expensive transfer.
Indeed it might be preferable to have these constant subtle movements
in image brightness than have either whole scenes too dark or too
bright, or have a slower iris response made by the operator.
BEST POSSIBLE SUPER 8 TRANSFER?
So let's say you want the best. Money is no object, right? Well,
take your film and cheque book to any high street broadcast telecine
house with a state of the art continuous motion transfer suite and
Super 8 gate (o.k.there is at least one such place in Australia
- Video8 Broadcast in Sydney). Ask for their best colourist. Spend
all the time necessary to grade and tweak the footage. Output to
Digi Beata or better digital tape.
Can't afford that? Go nano! - fixed price, and really quite good!
For more details of Nano Lab's transfer system, please see our 'telecine
transfer' page. After reading all this, you are now ready for