Q:
I have 6.5mm Elgeet
and a wide adapter for 5.5mm. Can I use these together?
ANS:
Yes. The difference between the 2
lenses (5.5 and 6.5mm) is minimal. Wide angle lenses on 8mm Bolex camera
are typically: 5.5mm, 6.5mm, 7mm, & 8mm. Normal angle is
12.5mm or 13mm and telephoto is approximately 36mm to 38mm also
sometimes shown as 1 1/2". Normal lens angle is about 2x
narrower that wide angle. Telephoto angle is about 2x narrower
than normal. This is of course, a rough approximation. See a better
explanation (more complicated - but with diagrams) here:
CHOOSING A LENS
Distance to the subject and
the field of view are to be considered when choosing a lens. Different angle
lenses present different views or distortions or compressing of the view. One can
first choose the angle - wide, normal, telephoto and then consider the
distance. Sometimes the distance is the primary factor to be considered
first. There is some confusion when using zoom lenses where the picture
appears to 'grow" as the camera lens is zoom from wide to telephoto.
The are actually several
things happening with a zoom lens: 1) The lens angle narrows as the zoom moves from wide to
telephoto, and 2) magnification of the image makes the picture appear larger.
What is actually happening is that angle is being 'traded" for distance.
Say you choose a wide angle prime lens for a group shot. You then adjust the
camera distance until all the people fit in the viewfinder. You can get close
to the subject which is usually best for lighting. Closer also will net a
sharper, better picture.
Using a telephoto lens to do
the same shot, you WILL have to back up until the group fits. The distance
added will cause the light hitting the film (or sensor in a digital camera) to
'fall off. The lower light will usually require a lower relative f/stop than
the wide angle F/8 instead of f/11. There are other considerations.
What the shot 'looks
like' when done is a consideration. The feeling that it gives to the viewer. Lots of stuff. And a
lot of it is subjective - your choice (camera operator). A wide angle,
extreme close-up shot of a face will make the face look distorted. A long lens
on the same face will need to move back and will 'flatten' facial features
(portrait) . In motion pictures, long lenses seem to 'expand time' for moving shot. A car
in the distance will appear to take longer to come into the camera's close
proximity. Forever it takes to 'get to the camera'. Then all of a sudden, it
whips by.
Zoom have their place where
you have enough light to be able to trade distance for light. In better
cameras, you don't even need to be close to get that picture. Zoom to it. Prime lens'
require more camera movement to get to the right position for filming.
Sometimes, only the zoom will work. Choices made determine the effect of the
lens on the film.
Q:
I know there is
fixed focus Pizar lenses for Bolex which should do the job, but how sharp are
they when you use them up close, but within the depth of field? Do they have that telltale "not critically
sharp" look?
ANS:
The fixed focus Pizar are
sharp enough at any distance for 8mm film, but are not designed for
extreme close up shooting. The depth of field is infinite on the far end and
limited to some fixed distance up close. On a Switar f/1.5. It focuses from
about 16" (close) to infinity at f/22 (beyond 60 feet or so). With
everything sharp.
A problem is with the extremely small iris openings
such as f/22, any lenses can suffer from diffraction. Diffraction can be seen
as unwanted light spots. One type of spot in the lens flare. Diffraction and flare can
be controlled with lens shade (hoods) and/or lens coating, or sometimes by just
changing the camera angle. At extremely small openings, and depending on the
lens used, the fix is to open the iris (small f stop) and uses a neutral
density (ND) filter to control the light.
The limiting factor of sharpness with 8mm or any film, is the film grain versus the width of the film. 8mm film stock is cut from 16mm, which is in turn cut from standard 35mm stock. With 3 cameras shooting the same film stock and at the same time, on the same subject, with the same light, and adjusted for lens differences, the 35mm would have the best perceived resolution and the 8mm the worst resolution. It's the film grain that make the quality suffer as the film image gets smaller.
The limiting factor of sharpness with 8mm or any film, is the film grain versus the width of the film. 8mm film stock is cut from 16mm, which is in turn cut from standard 35mm stock. With 3 cameras shooting the same film stock and at the same time, on the same subject, with the same light, and adjusted for lens differences, the 35mm would have the best perceived resolution and the 8mm the worst resolution. It's the film grain that make the quality suffer as the film image gets smaller.
Look at any 8mm footage. Grainy.
Look at the 35mm footage of the same subject. Much nicer. Remember, also that
you are generally much closer to projected 8mm footage than 35mm footage. 8mm
footage projected in a theater setting would be very bad. Coupled with the
projected image, the 8mm will also lose some sharpness from the projection
process. Remember, 8mm camera equipment was designed and sold for the
"home market". The lost cost of 8mm equipment was achieved by cutting
"corners".
Another limiting factor for
lens sharpness is there is usually an f-stop area that has the best sharpness
for that lens. And it usually NOT at the extreme ends of the lens. The lowest
or highest f-stops. F/2.8 typically do best starting a f/4 going to f/8 or so.
F22 on the same lens will always have less sharpness. All this varies with the
manufacturer and the design, number of lens elements, technology, etc, of the
lens. The more money you spend - then better the sharpness. Switars are better
than Yvars for Bolex, but both work well with 8mm.
Some of the cost cutting
involved with 8mm lenses was the use of lower quality glass, with imperfections
in the glass that tended to be ignored in the really cheap lenses. The
imperfections generally didn't show in the final projection and so were
tolerable. Projector lenses are even worse. I have a Keystone 8mm projector.
You can remove and hold to the Keystone's projector lens to the light and see extremely
small air bubbles in the glass! Doesn't affect the projected image at all.
Fortunately, camera lenses are better made.
Bolex sold two basic series of lenses: Yvar (cheap), and Switar (more money = better made). The Switars generally had lower f stop ratings (pass more light). Example: f/1.9 Vs f/2.8. At that time, the 1940s to 1965 or so, film was 25 or 40 ASA. You need a fast lens for indoors? F/1.8 or f/1.9 was common. Kern-Paillard and even made a f/.9 lens. An F/1.0 lens would pass 100% of the light thru the lens. The f/.9 lenses are quite rare and typically sell today for about $500 or so on ebay. No loss of light. In fact, the .9 lens GAIN light like a magnifying glass.
Bolex sold two basic series of lenses: Yvar (cheap), and Switar (more money = better made). The Switars generally had lower f stop ratings (pass more light). Example: f/1.9 Vs f/2.8. At that time, the 1940s to 1965 or so, film was 25 or 40 ASA. You need a fast lens for indoors? F/1.8 or f/1.9 was common. Kern-Paillard and even made a f/.9 lens. An F/1.0 lens would pass 100% of the light thru the lens. The f/.9 lenses are quite rare and typically sell today for about $500 or so on ebay. No loss of light. In fact, the .9 lens GAIN light like a magnifying glass.
Q:
I also know they have these lenses that allow reflex operation on a non-reflex camera. Do these work on the C8 or regular H8 or is the lens to film plane distance different or the lens mount not D-Mount? What is available that would work in place of my 5.5mm C8/H8 lens?
I also know they have these lenses that allow reflex operation on a non-reflex camera. Do these work on the C8 or regular H8 or is the lens to film plane distance different or the lens mount not D-Mount? What is available that would work in place of my 5.5mm C8/H8 lens?
ANS:
Reflex lenses made for
D-mount work well. What you get is an accurate view of what you are filming.
The reflex mechanism sends the light of the picture via a mirror when the
camera's shutter is close. Typical shutter angle is about 180 degrees, so half
the time you are filming, you can see the image. The other half of the time,
the image is 'hitting' the film. They sell on ebay for $25 and up. Sometimes
you see them on a C8 or B8. I seen them on D8Ls, also. Som Berthiot made lenses
to convert non-reflex Bolex models to
reflex operation. There were some made by the Japanese, also.
Here's a link to a Som
Berthiot at bolexcollector.com:
http://www.bolexcollector.com/lenses/60berthiot.html
Any reflex lens made for a D-Mount with work on the C8. The Pan Cinor 40R is probably the best lens for the C8. There is a focus diopter for getting sharp pictures for 'bad' eyes (like a binocular), and it uses a "split focus" system. You just turn the focus dial until the 2 split images match up.
http://www.bolexcollector.com/lenses/60berthiot.html
Any reflex lens made for a D-Mount with work on the C8. The Pan Cinor 40R is probably the best lens for the C8. There is a focus diopter for getting sharp pictures for 'bad' eyes (like a binocular), and it uses a "split focus" system. You just turn the focus dial until the 2 split images match up.
Q:
Was there ever made
a 6.5mm viewfinder adapter for Bolexs?
ANS:
Yes, 6.5 Bolex diopters were
made. Quite rare now. However, the 5.5 will work for any wide angle lens, since
the diopter is just used to "correct' the view as seen by the operator.
You just allow slightly less 'room' at the left/right edge of the view to
compensate for the difference in the 2 diopter values. The diopters view
angle of 5.5 will result in a slightly wider view of finished film when used on
a on a 6.5 lens, and even more wide on 7, or 8mm lenses.
