Neutral Density Filter vs. Slow Film

[Joseph Bell]

Hello there!

For a while I have been looking for slow C41 films, but I have found nothing slower than iso 100. Suddenly it occurred to me: why am I afraid of using a neutral density filter? I require slow shutter speeds in broad delight, so it seems that an ND filter is exactly what I'm looking for? I will be shooting the project with a Mamiya 645 and Hasselblad 500cm - 150mm lenses in both cases. The biggest downside I can think of: I'll barely be able to see through the WLF with a 6-stop ND filter on, which is probably why I've resisted an ND filter thus far. I would be more than grateful for your opinions on the matter. Sincere thanks!

p.s. I wasn't sure if I should post this thread here or in the Darkroom/Color film section. Please forgive me if I've chosen the wrong forum.

 

[wiltw]

An additoinal issue to sigifiicantly dense ND filter is that the inexpensive ones often TINT the color so it is no longer neutral.

If you set your camera on a tripod, you can fompose and focus WITHOUT FILETER, then mount the filmter shortly before exposure.

 

[MattKing]

I require slow shutter speeds in broad delight

I'm always hoping to be able to work in broad delight .
(Isn't auto-correct grand!?).
This is one advantage of using a rangefinder or TLR - particularly with IR filters.
wiltw's observation about tint is important. My sense is that the variable ND filters suffer from tint issues more than the fixed density ones, but they also do permit focusing and composing with less ND and then re-setting to more ND.

 

[Joseph Bell]

I'm always hoping to be able to work in broad delight .
(Isn't auto-correct grand!?).
This is one advantage of using a rangefinder or TLR - particularly with IR filters.
wiltw's observation about tint is important. My sense is that the variable ND filters suffer from tint issues more than the fixed density ones, but they also do permit focusing and composing with less ND and then re-setting to more ND.

That's a great point RE: the variable filters. My plan was to get hold of a high-quality filter in hopes of the filter living up to its name and staying neutral! I am considering doing the project with a rangefinder instead, if I can get hold of one! Great idea!

 

[Bill Burk]

Why not just do two stops. You will be able to see.

 

[villagephotog]

Hello there!

For a while I have been looking for slow C41 films, but I have found nothing slower than iso 100. Suddenly it occurred to me: why am I afraid of using a neutral density filter? I require slow shutter speeds in broad delight, so it seems that an ND filter is exactly what I'm looking for? I will be shooting the project with a Mamiya 645 and Hasselblad 500cm - 150mm lenses in both cases. The biggest downside I can think of: I'll barely be able to see through the WLF with a 6-stop ND filter on, which is probably why I've resisted an ND filter thus far. I would be more than grateful for your opinions on the matter. Sincere thanks!

p.s. I wasn't sure if I should post this thread here or in the Darkroom/Color film section. Please forgive me if I've chosen the wrong forum.

As Wiltw pointed out, the biggest gotcha', in my experience (reasonably extensive), is the possibility of color tint. If the filter is not strong (i.e. it's only 2-3 stops) tint is usually not an issue. But many 6, 8, and 10-stop ND filters introduce a tint, and they can increase vignetting. If you need a filter that strong, it's worth it to spend the big money on a top-quality one, in my experience. It's also my experience that every ND filter maker claims their filters are truly neutral and that is many times an aspiration rather than a fact -- i.e. it's a lie. So shop carefully.

I don't have as much experience with variable ND filters, but that's because I gave up on them quickly; every one that I tried gave a strong (and uneven) tint at their higher densities. So if it was a 4x-9x variable ND, for example, around 6-7x, I'd start seeing a tint that quickly got worse and more uneven, the denser the ND setting.

A predictable and even tint is not that big a deal to correct in Photoshop (and likely isn't if you're printing, but I don't have a ton of wet color printing experience, so I'm making an assumption there.)

At dusk, or any other situation where the light is lower, even a 3-stop ND filter on my medium format SLR (a Bronica GS-1 with f/4 and f/3.5 lenses) can interfere with focusing and even (with dark parts of the scene) composing. But it's a simple matter to do all that first, then just screw the filter on when I'm ready to shoot. Obviously, this is no issue with my rangefinder or TLR systems, but, of course, the classic danger there is that you can forget to fit the filter or take it off, and you won't notice in the viewfinder. Done it, like millions of others

 

[Bill Burk]

ND 0.6 filter will turn your 100 into 25 and that's f/16 1/25th second in bright sun. That's like shooting Kodachrome used to be.

 

[250swb]

You know what exposure factor to use if you are using an ND filter so focus with the filter off and then attach it and adjust your exposure accordingly. Take note of the reciprocity effect when making your exposure and everything will work out fine, unless.....you are using colour C41 film and the filter and/or reciprocity affect the colour balance, in which case you need to experiment.

 

[DREW WILEY]

Two issues. You'll probably get a bit of image degradation using a filter. How much depends on the quality of the filter, whether it's coated and shaded or not, and how clean it is when being used. The bigger problem, already mentioned, is that most ND filters are not completely neutral in hue. Many are a bit greenish. And once again, it seems you get what you pay for. Only the most expensive ones seem to be color neutral. But once aware of all that, they are potentially the answer you seek.

One more issue is never trust the nominal density on the package label. They tend to be somewhat off. My trick is to put them below the lens on one of my precise feedback enlargers and measure the without / with density change on a very precise easel densitometer. Since these devices are rare and expensive, you mighty try measuring through a spotmeter or TTL device instead to see if there's any quantitative anomaly. Going to that effort would be wise if using a slightly finicky color neg film like Ektar. I wouldn't worry about it for just fun experimentation with more ordinary CN films.

 

[Joseph Bell]

I am truly grateful for your wonderful insight and helpful ideas! Sincere thanks!

 

[Joseph Bell]

ND 0.6 filter will turn your 100 into 25 and that's f/16 1/25th second in bright sun. That's like shooting Kodachrome used to be.

That is very true!

 

[Joseph Bell]

I'm always hoping to be able to work in broad delight .
(Isn't auto-correct grand!?).
This is one advantage of using a rangefinder or TLR - particularly with IR filters.
wiltw's observation about tint is important. My sense is that the variable ND filters suffer from tint issues more than the fixed density ones, but they also do permit focusing and composing with less ND and then re-setting to more ND.

ha! Broad delight!! How delightful! I just noticed this. I was in a grumpy mood until I saw this - thank you!

 

[flavio81]

Hello there!

For a while I have been looking for slow C41 films, but I have found nothing slower than iso 100.

Most C41 ISO 100 films will be happy to be exposed at ISO 50 or even ISO 25. You will probably get richer colors too.

Just make sure to scan with a decent scanner (not a yucky flatbed) so you recover all the highlights.

Finally, expired C41 film will lose 1 stop over every 10 years. I had some Verichrome 160 rolls that were 20+ years old, and I had to use them at ISO 25 to get good density!

 

[Joseph Bell]

Most C41 ISO 100 films will be happy to be exposed at ISO 50 or even ISO 25. You will probably get richer colors too.

Just make sure to scan with a decent scanner (not a yucky flatbed) so you recover all the highlights.

Finally, expired C41 film will lose 1 stop over every 10 years. I had some Verichrome 160 rolls that were 20+ years old, and I had to use them at ISO 25 to get good density!

Thank you for this suggestion. My optimal iso is 12, but 25 would work well too. I am very fond of Ektar, although I've never considered shooting it at EI25. Certainly I can give it a try and see how it turns out.

 

[RalphLambrecht]

Hello there!

For a while I have been looking for slow C41 films, but I have found nothing slower than iso 100. Suddenly it occurred to me: why am I afraid of using a neutral density filter? I require slow shutter speeds in broad delight, so it seems that an ND filter is exactly what I'm looking for? I will be shooting the project with a Mamiya 645 and Hasselblad 500cm - 150mm lenses in both cases. The biggest downside I can think of: I'll barely be able to see through the WLF with a 6-stop ND filter on, which is probably why I've resisted an ND filter thus far. I would be more than grateful for your opinions on the matter. Sincere thanks!

p.s. I wasn't sure if I should post this thread here or in the Darkroom/Color film section. Please forgive me if I've chosen the wrong forum.

a neutral density filter will work well as long as it is truly neutral. just focus and compose without it and put it on afterwards to be able to see and focus properly.

 

[eli griggs]

Using ND filters, whatever the cost, is too problematic with colour films, and I feel you'd be better served by setting you negative iso speed one third less than box speed and using a good, twin glass lens polarizer, while metering through the filter, on or off camera.

IMO.