What's A Fast Lens?

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JGrube
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Post by JGrube »

"What kind of light have you been able to shoot in with that
Canon f/1.0?"

Brackish,

I've shot a night interior lit only by a single, 75-watt bulb, I just barely made it, but I got a useable exposure at 18fps with a 1.0 right on the number.

I've mostly used it for in-the-city dusk-for-night shots, at the tail end of the magic hour after all the street lights have turned on, again, between f1.0 and f1.2 (the light-level changes every minute at that time of day) I was able to get really nice exposures, bright streetlamps with everything else bathed in a deep blue light, just bright enough to see my actor walking down the street in the city at "night".

Oh yes, very important, I used Ektachrome 125 for those shots, I couldn't quite pull it off with K40 under those conditions. Oh well, that's why they make faster films, eh?

hope this is useful, :D

Jason
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Post by Brackish »

I saw mention of an "AF 310XL" which was said to be an auto
focus model. Is yours manual focus? I've also seen
mention of someone intending to remove a viewfinder
screen splitter (a small mirror) from inside the cam to
increase the low light reach. Do you have any knowledge
of what problems might be caused by removal of the mirror?
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Post by christoph »

Brackish wrote:I saw mention of an "AF 310XL" which was said to be an auto
focus model. Is yours manual focus? I've also seen
mention of someone intending to remove a viewfinder
screen splitter (a small mirror) from inside the cam to
increase the low light reach. Do you have any knowledge
of what problems might be caused by removal of the mirror?
i tryed to remove the little mirror but wouldn't recomommend to do so... it's made of the the same metal part that also holds the lens, so the only way to get it off would be to saw it off with a fine metal saw, running the danger to scratch the lens. also, it could well be that you get more vignetting because the mirror blocks light in the center and less at the corners... there's even a small ND gel enlarging the absorbing area in the center.

all that said, if you really need that 1/4 stop more light and dont mind shooting basically blind, go ahead and give it a try.. i bought three 310xl for less than 5 bucks each.

++ christoph ++

ps: i dont think the AF version has a very good low light lens
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Post by JGrube »

Brackish,

My 310xl is, in fact, auto-focus only, which does limit its usefulness, unfortunately. Like I said, I pretty much use it for special applications (low-light situations when supplemental light is not practical) and that's about it. I do a light meter reading first, and if I can shoot with an f1.8 or higher, I use one of my other cameras, which have manual exposure and can run at 24 fps. But I will say, the 310 works great in those adverse lighting conditions, you just have to make sure that nobody shines their headlights directly into the lens or walks in front of the camera in a white suit, as this will fool your automatic exposure into closing down.

There is one manual option on the exposure, if you pull up on the little red tab at the front of the camera, it allows the auto exposure to ONLY take a reading from the center of the frame, this works well if the scene is backlit and will help to keep the automatic feature from closing the aperture down TOO much and turning your actor into a silhouette. But that's about the only "manual" option on the camera.

Jason
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Post by Brackish »

I suppose the auto-focus hunts alot, huh? Are the non-AF cameras
a fixed focus? Or are they manual focus?

What's the fastest color reversal film made?
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Post by JGrube »

Yup, that is the dreaded problem with auto exposure, you just have to compose your shots a little more carefully to avoid exposure "accidents".

I'm not aware of a manual-exposure version of the 310xl. Too bad, BUT, there are a decent number of Super8 cameras with f1.2 lenses, which are still awfully fast, and a large number of these cameras do have manual exposure and can run at 24fps. If your looking for more of a general use camera with a fast lens, one of these might suit you well.

For Super8, as far as I know, Ektachrome 125 is the fastest KODAK stock (I've not used Fuji, I've heard they make faster reversals perhaps). In 16mm, Ektachrome 400 is the fastest. They don't make it in Super8, BUT, if you can find the right lab, you can have 125 pushed two stops to an equivalent speed, with only slightly more grain than Ektachrome 400 (although I'll admit, this is still quite grainy, so be warned). If you really need the extra speed, this is an option. Call the lab first and see if they push process Super 8.

Jason
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Re: What's A Fast Lens?

Post by tr0x »

well, i only got this info (f0.5) from a few web searches, so one never knows... but the sources seemed to be quite plausible...
yes, i absolutely agree, i've taken the photo of 40mm f/0.33 from http://www.nadir.it:

"http://www.nadir.it/pandora/c_zeiss.htm



bye.

tr0x
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Re: What's A Fast Lens?

Post by christoph »

tr0x wrote:
well, i only got this info (f0.5) from a few web searches, so one never knows... but the sources seemed to be quite plausible...
yes, i absolutely agree, i've taken the photo of 40mm f/0.33 from http://www.nadir.it:
"http://www.nadir.it/pandora/c_zeiss.htm
hmm.. my italian is a bit poor, but it seems to me that the lens might not have been f0.33 after all: "Quatsch" means "nonsense" which could indicate that the maker of the lens knew that it was not possible...

of course i'm only making vauge guesses here.. anybody that understands italian cares to clarify?
(otherwise i'd have to dig into those books about optical laws, urgh ;)

++ christoph ++
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tr0x
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Re: What's A Fast Lens?

Post by tr0x »

hmm.. my italian is a bit poor, but it seems to me that the lens might not have been f0.33 after all: "Quatsch" means "nonsense" which could indicate that the maker of the lens knew that it was not possible...
exact!



bye.

tr0x
Brackish
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Post by Brackish »

christoph wrote:
Brackish wrote: all that said, if you really need that 1/4 stop more light and dont mind shooting basically blind, go ahead and give it a try.. i bought three 310xl for less than 5 bucks each.

++ christoph ++

ps: i dont think the AF version has a very good low light lens
So what would be the difference between the auto focus and
the manual focus for low light? Aren't the lenses identical? Anyone else
know anything about the AF diffenence?
And how is the AF? Does it hunt for focus quite a bit?
Quick to lock on?
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Post by S8 Booster »

Brackish wrote:
And how is the AF? Does it hunt for focus quite a bit?
Quick to lock on?

The AF does not hunt. It is a pre-shoot focus and lock there when you pull the trigger. No hunting.

I have both the 310 AF Xl-S and the 310 XL.
I like the XL better but the AF does a decent job but again i preffer more manual control. The XL-S is noticably more silent. You can hear them compared here.



Check out this old post about cam noise. The cams are listed by user ranging and some old real test.

Camera Noise contest: owner of several S8 camera please post

Also check these real samples - the clips.
S8 Booster wrote: Beaulieu 5008, Elmo 1012 S-XL, Canon 1014 Xl-S, Nikon R10, Canon 310 AF XL-S, Canon 310 XL at 18 & 24 fps (Some):

Tiny compiled film for you to judge for your self:

HQ sound 8 mb
ftp://ftp.filmshooting.com/upload/video/mov/Noises.mov

LQ 800 kb (Web film somewhat distorted sound)
ftp://ftp.filmshooting.com/upload/video/mov/Noise.mov

This "test" was done under the following conditions:

Camera mounted on a tripod about 1 meter away from the Sony DCR PC120. The PC 120 put on noise dampening material.
In some cases at 24 fps particulary the Sony´s auto level control is activated so the sound is somewhat distorted. When it appears it is as if the sound is louder than it really is. Most appearent on the loudest cameras. Do not be confused by this.

I can not really decide if the Canon 1014 Xl-S or Elmo 1012 S-XL is the most silent of the two but my impression is: at 18 fps the Elmo is most silent and at 24 fps the Canon is (a little) more silent. The Canon 310 AF XL-S is pretty silent too.

Only the Nikon R10 has a film in it so the noise levels for all other cams will normally rise somewhat with film.

I always regarded the Elmo as the most silent cam of the bunch but the Beaulieu 5008 MS was really sigificantly more silent. Seem that I have to get a decent (Canon) Lens to it rather that sell it like I planned. I am pretty sure that this cam with some care can be used un-blimped with sync sound recording. Thanks heavy metal casing.

In my view the Elmo and The Canon are not bad either - the Canon is very smooth running at all speeds.

Running order as follows:

18 FPS
Beaulieu 5008 MS - no film - 18fps
Elmo 1012 S-XL no film - 18 fps
Canon 1014 XL-S - no film - 18 fps
Nikon R10 - with Provia F400 - 18 fps
Canon 310 AF XL-S - no film - 18 fps
Canon 310 XL - no film - 18 fps

24 FPS
Beaulieu 5008 MS - no film - 24 fps
Elmo 1012 S-XL no film - 24 fps
Canon 1014 XL-S - no film - 24 fps
Nikon R10 - with Provia F400 - 24 fps
R
..tnx for reminding me Michael Lehnert.... or Santo or.... cinematography.com super8 - the forum of Rednex, Wannabees and Pretenders...
Brackish
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Post by Brackish »

So, the AF does focus by itself, but once you start shooting,
the focus is locked in the position it was when you
first began shooting? Correct? Is there any provision for
manual focusing with the AF?
So if I were trying to keep the focus on a subject who
was walking toward the camera while being filmed, it
would be best not to use an AF camera for this? Correct?
Have you noticed anything about the AF which would
make it not as good in low light as the MF?
Wonder what they did to the sound model to make it
quieter?
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Post by S8 Booster »

Brackish wrote:So, the AF does focus by itself, but once you start shooting,
the focus is locked in the position it was when you
first began shooting? Correct?
This is how I experience it - yes.

Incredible depth of field so it hardly fails.

Brackish wrote: Is there any provision for
manual focusing with the AF?
Not that I can find or see.
Brackish wrote:So if I were trying to keep the focus on a subject who
was walking toward the camera while being filmed, it
would be best not to use an AF camera for this? Correct?
I guess the huge DOF fixes most of this but at extreme close ups it may be an issue. Never actually checked.
Brackish wrote:Have you noticed anything about the AF which would
make it not as good in low light as the MF?
If there is a difference it is not obvious to me.
Brackish wrote: Wonder what they did to the sound model to make it
quieter?
The housing is beefier and totally different. Some sound dampening efforts there I guess:

AF XLS
Image

XL
Image

R
..tnx for reminding me Michael Lehnert.... or Santo or.... cinematography.com super8 - the forum of Rednex, Wannabees and Pretenders...
FilmsUP
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Post by FilmsUP »

Your all wrong! A fast lens is ANY lens that is sold on eBay, with the "Buy Now" feature within 20 min. of placing the add. .

Hope this helps! :wink:
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Post by Dusty »

On the AF 310 XL-S: Yes, it's pre-focus, and no, there's no way to manually focus it. The instruction booklet actually directly addresses the problem of filming something walking toward the camera: it says don't. It goes on to say that if you have to, focus on something half-way between where the subject starts and stops and hope that the DOF takes care of it.

I use mine for filming in existing (low) light areas where taking my own lighting is impractical. It's also remarkably quiet, which is very nice in such locations as my primary camera might make people think they're being shot at.

(Also, take care that what you're filming reflects infrared light, otherwise it's not going to be able to focus on it.)
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