Long exposure photography with film?

[fenderphoto]

I am awaiting the arrival of my Canon A-1. I am going to purchase black and white film. What film ISO would I choose for long exposures. I.e. Silky water, headlight trails ect…

 

[peter27]

I would choose as low a speed as is available where you are. Iso 50 or 25 perhaps.

 

[iolair]

I would choose as low a speed as is available where you are. Iso 50 or 25 perhaps.

This.

You may also want to consider a decent quality Neutral Density filter.

 

[limr]

I would choose as low a speed as is available where you are. Iso 50 or 25 perhaps.

This.

You may also want to consider a decent quality Neutral Density filter.

All of this ^^^ Ilford Pan F ISO 50 is quite nice.

 

[amolitor]

Film speed hardly matters for this application. Do you want grain or not?

 

[Gavjenks]

Speed doesn't matter, but other things about film do. Specifically, how much the film suffers from "reciprocity failure." This is when exposure times go up faster the longer they are, in a non-linear way. So for example, up to 1 second, exposure times may be accurate as metered. But if you meter for 8 seconds, you may need to actually expose for 20. The difference gets bigger and bigger the higher you go. All films have a curve you can usually look up to see how susceptible they are to this. Some curves are so low though that you can basically ignore it. Other ones might require you to keep the shutter open massively longer (like 160 seconds when you thought you only needed 30).

If your goal is just to get silky water, etc., then reciprocity failure is not a NEGATIVE factor. In fact, it's pretty convenient: you can save money and effort by being able to use weaker ND filters, since the reciprocity failure itself will add some of the exposure time for you. For instance, for Ilford HP-5, if you want a 30 second exposure correctly exposed, you should METER for about 10 seconds, and then actually leave it open for 30 anyway. So you can use 1.3ish fewer stops of ND filter for the same result as with a more linear film.

So if this is the kind of shot you take:
1) You need to be aware of your film's reciprocity failure curve, no matter what brand, to get proper long exposures.
2) If your goal is long exposures with silky water, etc., you will want to actively seek out a film with a lot of reciprocity failure to make it that much easier to achieve.

 

[timor]

I am awaiting the arrival of my Canon A-1. I am going to purchase black and white film. What film ISO would I choose for long exposures. I.e. Silky water, headlight trails ect…

Choose Fujifilm Acros. It is the best for long exposures, reciprocity failure (Swarzschild Effect) is minimal.
http://www.digitaltruth.com/products/fuji_tech/NeopanAcros100.pdf
No exposure compensation is required under 120 sec, Above that only 1/2 stop.

 

[Gavjenks]

I am awaiting the arrival of my Canon A-1. I am going to purchase black and white film. What film ISO would I choose for long exposures. I.e. Silky water, headlight trails ect…

Choose Fujifilm Acros. It is the best for long exposures, reciprocity failure (Swarzschild Effect) is minimal.
http://www.digitaltruth.com/products/fuji_tech/NeopanAcros100.pdf
No exposure compensation is required under 120 sec, Above that only 1/2 stop.

Why would you NOT want reciprocity failure if you're doing long exposures?

 

[amolitor]

Silky water and headlight trails isn't really in reciprocity failure territory.

 

[timor]

By the "silky water" are trees, stones etc. Maybe fenderphoto want them in normal values. Just my thought. Anyway, for silky water long exposure is not the only option. (Sure, this depends on equipment ).

 

[Gavjenks]

Silky water and headlight trails isn't really in reciprocity failure territory.

Sure it is! Some films, like HP5 again, have failure at like 1/2 second or longer. At even just a few seconds, well within range of times for silky water, the failure can already be a whole stop or more. Super annoying for just tyipcal photos where you aren't looking for time blur. But if you WANT that, it is actually helpful, because you can expose longer with less powerful NDs, brighter light, wider apertures.

Other films have no significant failure for minutes or longer. Easier to think about, but actually less powerful for very long exposure photography.

 

[JTPhotography]

I think you guys over think this stuff. Go in the field with a notebook and a slide rule and start calculating reciprocity failure and see what that does to your creativity.

Get some ISO 50 and 100 and experiment.

 

[MK3Brent]

Yeah I came here to mention reciprocity failure... read up on it.

It will be different for each film you use.

 

[vintagesnaps]

By this time we may never know how this worked out for the OP. I agree, take along a notebook! that's helped me remember later what I did that worked (or didn't, which helps to know that too sometimes).

 

[webestang64]

I personally don't give a hoot about reciprocity failure............I like it.........