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URGENT - using tri-x in bright sunlight on a canon 310 XL


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#1 Sherwin Akbarzadeh

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Posted 15 August 2008 - 08:18 PM

Hi Guys,

I'm heading to mexico tomorrow and was looking forward to shooting some of the scenery on my canon 310XL with some tri-x b/w reversal (7266) that i have lying around. This was until i found out that it's an extremely fast film that may be overexposed in bright sunlight. How do i shoot this film and have nice contrasty results in daylight? I don't have time to buy an external filter.

This is my plan:
I have read that it is possible to cut a notch near the bottom part of the cartridge (on the gate-facing side), so that the internal filter cancellation pin is not pressed. I will set the internal filter switch to 'daylight'. I will leave the red meter filter down (If light to the meter is being filtered then the camera will compensate by opening the iris even wider, right?).

Is there anything else I can do? Any DIY tricks? yellow cellophane?! Anything.

Please let me know. I'm leaving in 12 hours!

Cheers
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#2 Chris Burke

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Posted 15 August 2008 - 08:45 PM

the best thing you could to while shooting with that camera in that particular setting is bring along a red filter R2. I think that it is a 2 stop difference, perhaps more. Your camera has a 43mm filter thread, so the best thing to do is, not to use the internal filter at all, it is not needed. Instead attach the red filter or any other black and white filter, say yellow or orange, to the front of the camera. the red filter will increase the contrast the most and reduce the amount of light coming in. this is really your best option. since your camera is set up so well for low light. You might want to try to shoot some stuff at dusk or there abouts. Remember, 43mm r2 filter.
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#3 Sherwin Akbarzadeh

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Posted 15 August 2008 - 10:32 PM

Thanks Chris, but i'm going to Mexico tomorrow - buying a filter won't be possible.

I was hoping there is a DIY answer. Is what i described about creating a notch on the cassette so that the filter cancel button is not pressed accurate? Using the internal filter is better than nothing, right?

I was hoping to take more stills than video. Will this affect the exposure at all?

Cheers
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#4 Fran Kuhn

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Posted 16 August 2008 - 12:28 AM

Thanks Chris, but i'm going to Mexico tomorrow - buying a filter won't be possible.

I was hoping there is a DIY answer. Is what i described about creating a notch on the cassette so that the filter cancel button is not pressed accurate? Using the internal filter is better than nothing, right?

I was hoping to take more stills than video. Will this affect the exposure at all?

Cheers


Super-8 Tri-X is rated at 200 ASA in daylight, so using the classic "sunny/16" exposure rule, you would have to have a shutter speed of 1/200th at f16 in direct sun for correct exposure. For movie cameras with a "standard" 180-degree shutter, that equates to 24fps (1/48th second) at f32.

Using the Canon's internal 85 filter will cut the light by 2/3 of a stop, plus converting the daylight to "tungsten" by using the filter will cut another 1/3 stop (Tri-X is less sensitive to tungsten light). So, in bright daylight, using the internal filter, your rated ASA for Tri-X will be about 100 ASA. If the camera and lens aperture can be set manually, this means you'll need to stop the lens aperture down to f22 at 24fps when using the internal 85 filter in bright sun.

On thing to consider: I believe the 180XL has a wider-than-normal shutter angle designed to allow better low-light performance. I don't have the exact specs for that camera, but if it's, say, a 210-degree shutter, you'll still be about 1/3 of a stop overexposed at f22 @ 24fps with Tri-X in direct sun. If the lens will stop down as far as f32, you'll can set it to f22 1/3 and be okay. The depth-of-field will be about as deep as possible, but if that doesn't bother you, at least you'll be able to get a decent exposure.

BTW the 85 filter will add a little contrast in daylight. Reversal films are pretty contrasy to begin with, so keep this in mind if you're shooting an harshly-lit subject.

-Fran
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#5 Jim Carlile

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Posted 16 August 2008 - 05:02 AM

No, if you cut a notch in the cartridge just to be able to use the internal 85, the circuitry will tweak the meter open an extra 2/3 stop to compensate for it. So that's no good.

Here's a partial solution-- cut a notch in the cartridge, and the meter will read the film at ASA 250; the film is 200. That way, it will close down the aperture a little, thinking that it doesn't need as much light. You can use the internal 85 if you want to, but it won't make any difference to the exposure.

Yes, keep the red thingy down-- if you pull it up, it's a waterhouse stop that acts as a filter in front of the meter window-- it will open up the aperture even more, so keep it down.
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#6 Chris Burke

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Posted 16 August 2008 - 07:37 AM

Thanks Chris, but i'm going to Mexico tomorrow - buying a filter won't be possible.

I was hoping there is a DIY answer. Is what i described about creating a notch on the cassette so that the filter cancel button is not pressed accurate? Using the internal filter is better than nothing, right?

I was hoping to take more stills than video. Will this affect the exposure at all?

Cheers



I think your camera has an override for the automatic exposure, plus or minus a stop. You can use that in the minus direction to help out. What are you shooting? Outdoors in the very bright sun? Stopping down the apeture and filtration are the only real options you have. What are the ƒ stop markings? How high do they go?

Edited by Chris Burke, 16 August 2008 - 07:39 AM.

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#7 Kenneth Wajda

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Posted 16 August 2008 - 11:32 AM

Shoot backlit. Makes for pretty pics and will work with your exposure.
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#8 greg ocallaghan

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Posted 16 August 2008 - 03:11 PM

Shoot backlit. Makes for pretty pics and will work with your exposure.


As a DIY solution, maybe use your sunglasses as a filter? :P
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#9 Chris Burke

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Posted 16 August 2008 - 06:45 PM

As a DIY solution, maybe use your sunglasses as a filter? :P




bravo! best suggestion yet. I have done this and it works to a degree. In a pinch as he seem to be, this is the ticket. I just think that he won't see any of this until afterwards
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