Tri-X and Beaulieu 2008

[Franco Bogino]

Hi All

 

I am looking for advice on using Tri-X on my Beaulieu 2008. I have no real understanding of film stocks so I need some basic info to start me off!

 

Firstly I need to understand the difference between Daylight and Tungsten rating. Why is a film rated differently for these two scenarios? Is it simply that different types of light cause a slightly different chemical reaction on the film? I always assumed light was light.

 

Secondly I need to understand the use of the 85 filter. I believe Tri-X is rated as 200D (without filter)/ 160T (without filter). Does this mean that it will have a different effective rating if used with the filter.

I understand the principal behind the filter when using colour film, ie to correct the tones on colour film (...to correct Tungten film used in daylight shoots?), but I have also read that it is worth using it with black and white film to enhance the contrast.

 

Regarding the Beaulieu 2008, I think the internal filter has been removed, but I would like to know a way to check this to be sure. It came with a filter which is screwed onto the front of the lens. Assuming that the internal filter has been removed, will the internal light meter be giving me a correct reading with filter on or do I need to rate the film at a different ISO?

 

The camera has two markings on the ISO selector, one red dot and one white dot. Apparently the red dot is for Colour Tungsten film, and the white is for Colour Daylight or B&W. Which dot should I use if there is no internal filter?

 

Many Thanks

 

Francesco

[Chris Burke]

you are very close. Tri X is more sensitive to blue(daylight) than tungsten light. That is why there is a different ratings for each. I would not use that internal filter if there is one, it is probably quite old and will degrade your image. With black and white, using an external 85 filter will give you more contrast, much like using a yellow, orange or red filter. With Tri x you want to nail the exposure, so the 85 filter takes away 2/3 of a stop of light, so factor that in when you meter using an external light meter. You should try to get a manual for the camera. I am not sure what the specs are for it, but it's shutter angle may be 1/86 which will yield a sharp image but will require more light. Perhaps some other out there who know Beaulieu's can chime in. Alfredo???

[Franco Bogino]

Hi Chris

 

Thanks for the reply. Regarding the sensitivity of the film to daylight and tungsten, if I have the 85 filter on the lens should I rate the film as 160ASA (Tungsten) even when shooting in daylight? i.e does the filter effectively make the light reaching the film have the same exposure effect as Tungsten? I will be using the internal meter, so it will already be measuring the decreased light intensity

.

As for the camera's internal filter (if it has one), if there is anyone else who knows the camera I would like to know how to check the filter is not in place. As Chris has confirmed I feel it is better to use my own filters directly on the lens.

 

Thanks again

[andy oliver]

Its been a long time since I've filmed with a 2008 but i'm pretty sure that once the 85 filter is swung out of the optical path a clear filter is swung into the optical path. So if you have concerns over the 85, the same would apply for the clear filter, both filters would require replacing. Best way to see if an 85 filter is present is to operate/run the camera, then remove the power whilst the trigger (under the lens) is still depressed. Remove the lens, run the camera, remove the power and hopefully the shutter will remain open. You can then look into the optical path towards the gate and check whether the 85 is in situ or not.

Remember that if you decide to remove the 85 filter to have the lens adjusted to the camera body, as the removal of the filter may affect the back focus, and you could obtain soft images when the lens is used wide open (f1.9?) and on its widest setting (8mm assuming you have an 8-64 lens on the camera).

To expose tri-x remove the 85 filter, rate at 200asa in daylite, 160 in tung. No need for the 85 flter for tri-x. Personally i tend to expose tri-x at 160 asa in daylight.

If you 2008 has auto iris, try to avoid auto iris, obtain the exposure and lock the iris, beaulieu auto iris are a bit irratic (imo) and not that reliable.

[Chris Burke]

Hi Chris

 

Thanks for the reply. Regarding the sensitivity of the film to daylight and tungsten, if I have the 85 filter on the lens should I rate the film as 160ASA (Tungsten) even when shooting in daylight? i.e does the filter effectively make the light reaching the film have the same exposure effect as Tungsten? I will be using the internal meter, so it will already be measuring the decreased light intensity

.

As for the camera's internal filter (if it has one), if there is anyone else who knows the camera I would like to know how to check the filter is not in place. As Chris has confirmed I feel it is better to use my own filters directly on the lens.

 

Thanks again

 

First of all, have you shot a test? That is going to tell you loads about the camera and what it can do. You should rate the film outdoors with an 85 on the lens at 125. I always like to rate reversal film a third under, to protect the highlights, if I can. This would make it ASA 160, but this is more a matter of taste. The sensitivity of the film changes with the type of light exposing it. Daylight requires the film to be rated at 200, with the 85 in place knocks it down 2/3 of a stop to 125. What Andy has said about the back focus is very valuable advice. Testing will help you determine whether or not this is an issue. Metering with the internal meter is a crap shoot at this point in time. True it should meter taking into account all the factors that effect the exposure, but that is only if it is working properly. What sort of images are you going to be happy with? Some folks I know shoot super 8 as it was originally intended, as a run and gun fully automatic consumer format and they get funky looking footage, which can be great. The Beaulieu cameras were intended for professional use and can produce very sharp looking frames, so spending some time finding out if the meter is working and what the specs are, such as shutter angle or speed are essential. One way would be to point the camera at a gray card in full sun with say 100 speed film (because I think the shutter is 1/86) and see what you get. It should read almost a third over f16, using the sunny 16 rule. Phil Vigeant at Pro8mm and Alfredo Parrara of Hyde Park really know these cameras and I'd love to hear there opinions. I really don't know Beaulieu's.

 

Ideally, I'd have the internal filters if any removed, back focus checked and use a spot meter. When shooting outdoors I would use perhaps a graduated ND or pola/red or orange filter combo, depending upon the weather and desired look. Skies can easily blow out or foreground buried in shadow with this film, but It can yield beautiful imagery that is like no other. If alfredo doesn't pick up this thread I'll shoot him a line.

[Franco Bogino]

First of all, have you shot a test? That is going to tell you loads about the camera and what it can do. You should rate the film outdoors with an 85 on the lens at 125. I always like to rate reversal film a third under, to protect the highlights, if I can. This would make it ASA 160, but this is more a matter of taste. The sensitivity of the film changes with the type of light exposing it. Daylight requires the film to be rated at 200, with the 85 in place knocks it down 2/3 of a stop to 125.

 

Hi Chris

 

Thanks for taking the time to explain all this. It's all a bit confusing but so valuable. So what I'm not understanding is this:

 

If Tri-x is rated 200 for Daylight and 160 for Tungsten, and if the purpose of the 85 is normally to make film respond as if under Tungsten, then shouldn't the Tri-x be rated as 160 in daylight with the filter?

The other factor that points in this direction is that the camera has 2 dots on the filmspeed dial, one red and one white. I do not have the manual, but someone on another post quoted this from their manual:

 

"Set the ASA speed of the film marked on the knob opposite the red mark (colour films for artificial light) or opposite the white mark (for daylight colour films and black and white)."

 

I am guessing this is something to do with the 85 filter automatically going into place for certain film types. I am guessing that Tungsten films with the standard notch will cause the inbuilt filter to come into play so that the film can also exposed in daylight conditions.

 

When the white dot is positioned at 200ASA, the red dot is positioned positioned roughly at 150 or 160ASA (the scale is a bit small to make it out accurately). This is quite a bit higher than the 125 you suggest, is this because you are calculating for reading from an external light meter?

 

I have shot a test reel and am waiting for it to come back. I did nothing as professional as using a grey scale, I just pointed it at the same object in daylight and tried different film speed settings. I will have to judge which setting worked best when I project the reel...I suppose this will tell me something at least.

 

As for the lens focussing, this seems to be ok, but I also shot tests for this on the last reel.

 

Thanks again for your advice

[Chris Burke]

the 85 filter, whether internal or external, is normally used for color photography. I think that may be where some of your confusion is coming from. Black and white film doesn't need it. the iso speeds stated on the film are for no filter, because it is not needed. If you were to use it with black and white film, it takes about two thirds of a stop of light and bumps up the contrast a bit, much like the orange filters you can use. Tri - X is 200 under daylight period. if you put an 85 in front of the lens, it is 125 iso, the two thirds I was speaking of. Too bad you didn't record what the f stop and frame rates were used when you were shooting. then you would have a better idea of what does what. If the camera rates the film at 160 with the internal filter on, it isn't the end of the world, that is a third under. Perhaps another test roll is in order.

[Franco Bogino]

Hi Chris

 

Sorry, I still don't get it. I understand that the filter reduces the light reaching the film, but I still don't understand the reasoning behind the change in effective rating of the film. If it is simply because of reduced light would you not stick with the film's stated rating, as the reduced light is measured by the camera's internal meter (I'm under the impression that the Beaulieu measures light through the lens).

This would normally be the case with a neutral density filter or a polarising filter.

This is why I was wondering if the change you apply to the effective rating of the film is actually due to the quality of light passing through the filter rather than the intensity. I understand that the 85 filter is actually intended for colour film, to achieve correct colour balance, but the same principles of sensitivity would apply to B&W, the only difference is that there is no colour balancing. What I mean by 'quality of light' passing through the 85 is that it is effectively intended to turn daylight into Tungsten light so that the film is exposed in the same way as under actual Tungsten.

This makes sense to me based on your earlier explanation of the two ratings associated with B&W films like Tri-X, ie that B&W film is less sensitive to Tungsten light (and it must be the case for colour films too because they also have dual exposure ratings, like Ektachrome 100D, which should be rated as 25 ASA when using filter 80).

 

Also, you mentioned that although you would rate the film as ASA125 when using the 85 filter, you do actually rate it as 160 to protect the highlights.

 

Sorry for the continuing questions, you clearly have solid practical experience of what adjustments to make to the filmspeed ratings, which I will be applying to my next roll. I guess I just want to understand clearly the principals behind it so I can apply it to other situations and stocks.

 

...it would probably be useful to find out for sure if the Beaulieu is measuring light through the lens. This is what the brochure says:

 

"The exposure - indicated by the reflex photocell - is automatically corrected for the transmission coefficient, and extension of the selected lens and, when applicable, for the absorption coefficient of the filter. The photocell controls the "Reglomatic" system (with monitoring pointer built in the viewer)."

 

I think the reason for the two dots on the camera's filmspeed dial is that the built in 85 filter sits between the reflex and the film gate, so light will not pass through the filter before reaching the meter. This would therefore require a manual compensation of the effective film speed in cases where the filter was put into place (ie on appropriately notched colour cartriges).

 

Anyway, thanks for your continued patience and advice.

[Chris Burke]

Hi Chris

 

Sorry, I still don't get it. I understand that the filter reduces the light reaching the film, but I still don't understand the reasoning behind the change in effective rating of the film. If it is simply because of reduced light would you not stick with the film's stated rating, as the reduced light is measured by the camera's internal meter (I'm under the impression that the Beaulieu measures light through the lens).

This would normally be the case with a neutral density filter or a polarising filter.

This is why I was wondering if the change you apply to the effective rating of the film is actually due to the quality of light passing through the filter rather than the intensity. I understand that the 85 filter is actually intended for colour film, to achieve correct colour balance, but the same principles of sensitivity would apply to B&W, the only difference is that there is no colour balancing. What I mean by 'quality of light' passing through the 85 is that it is effectively intended to turn daylight into Tungsten light so that the film is exposed in the same way as under actual Tungsten.

This makes sense to me based on your earlier explanation of the two ratings associated with B&W films like Tri-X, ie that B&W film is less sensitive to Tungsten light (and it must be the case for colour films too because they also have dual exposure ratings, like Ektachrome 100D, which should be rated as 25 ASA when using filter 80).

 

Also, you mentioned that although you would rate the film as ASA125 when using the 85 filter, you do actually rate it as 160 to protect the highlights.

 

Sorry for the continuing questions, you clearly have solid practical experience of what adjustments to make to the filmspeed ratings, which I will be applying to my next roll. I guess I just want to understand clearly the principals behind it so I can apply it to other situations and stocks.

 

...it would probably be useful to find out for sure if the Beaulieu is measuring light through the lens. This is what the brochure says:

 

"The exposure - indicated by the reflex photocell - is automatically corrected for the transmission coefficient, and extension of the selected lens and, when applicable, for the absorption coefficient of the filter. The photocell controls the "Reglomatic" system (with monitoring pointer built in the viewer)."

 

I think the reason for the two dots on the camera's filmspeed dial is that the built in 85 filter sits between the reflex and the film gate, so light will not pass through the filter before reaching the meter. This would therefore require a manual compensation of the effective film speed in cases where the filter was put into place (ie on appropriately notched colour cartriges).

 

Anyway, thanks for your continued patience and advice.

Why do you want to use an 85 filter, you don't need it at all. Yes, I tend to rate reversal film one third under, but it really is a matter of taste. But for to ease a bit of the confusion, forget the 85. I would disengage the filter entirely and shoot a test roll to see how the internal meters are working or not. I tend to doubt they will be accurate. The advice I am giving is assuming that you will be using an external meter. If the internal meter is working properly, then all this is a moot, because yes the camera does meter through the lens. It is just that once you figure out where the proper exposure lies, then you should be using a spot meter for the best possible exposure. The internal meter will give you an average and if you have a very bright sky, your foreground will be very dark. Tri-X can be tricky to expose properly, but not as difficult as some will lead you to believe. Best rule of thumb for reversal is meter for the highlights and throw light into the shadows.

[Franco Bogino]

Ok, that makes perfect sense now. To be honest, the reason I was using the filter was because I had read that it improves the contrast, especially for things like blue skies with clouds etc. An 85 filter came with the camera, but I understand that a normal yellow filter would also do the job.

I'll take your advice and shoot a test roll without the filter and using a variety of exposures to test the internal meter. One more thing to check with you, am I understanding correctly the principles behind the 85 filter and how it changes the light effectively into tungsten?

 

Thanks for clearing this all up. I've shot quite a bit of stuff before with other cameras, and with lovely results. The difference now is that I'm looking to shoot a little horror film indoors with lots of shadows, so it all has to be a bit more precise. I gueess my next investment will have to be a light meter!

[Chris Burke]

Ok, that makes perfect sense now. To be honest, the reason I was using the filter was because I had read that it improves the contrast, especially for things like blue skies with clouds etc. An 85 filter came with the camera, but I understand that a normal yellow filter would also do the job.

I'll take your advice and shoot a test roll without the filter and using a variety of exposures to test the internal meter. One more thing to check with you, am I understanding correctly the principles behind the 85 filter and how it changes the light effectively into tungsten?

 

Thanks for clearing this all up. I've shot quite a bit of stuff before with other cameras, and with lovely results. The difference now is that I'm looking to shoot a little horror film indoors with lots of shadows, so it all has to be a bit more precise. I gueess my next investment will have to be a light meter!

 

 

an 85 filter is to use tungsten film in daylight. Used with black and white it will increase contrast. for indoors, you won't need it at all. Tri-X is rather contrasty already, it is all in the lighting. Not so much filters for interior use. For exterior, you may want to use them, also look at using a polarizer for darkening skies.

[Franco Bogino]

Thanks Chris, that's useful advice. I'm getting my head round the lighting thing now.

 

Unfortunately I have another problem to resolve now. I received my test roll back and can now see there is an issue with the lens. There is a weird thing going on where the edges of picture are in focus, but as you move to the centre of picture if becomes slightly soft. The soft area is circular, with a diameter of perhaps 5-6mm, with softness decreasing as you reach the outer edge of the circle.

It also appears that the amount of softness changes as the focus point changes. I know collimation can be a problem in these old cameras, but does this sound like a collimation issue?

I think the inbuilt filters have been removed, but I am still not 100% sure. I tried taking the lens off and running the camera with the film door open. I peered through the gate with light shining through it and couldn't make out anything in the way, it seemed to be completely clear.

 

I also found this article about collimation

 

http://lavender.fortunecity.com/lavender/569/lenscollimation.html

 

has anyone else used it? Is it any good?

 

Thanks

 

Franco