Red filters but no black skies

[Lilserenity]

Hiya,

I consider myself to be a competent photographer but I have a lot still to learn, and sometimes the questions I ask are probably real dummies questions so to speak but I have to ask this.

I sometimes use a red filter (Hoya 25A) on my lenses on days with blue skies (pure blue skies, no haze, or just a peppering of clouds) but the results I get back are all well exposed but the sky isn't black or remotely near it, more like the grey you'd get on any picture without a red filter. I open up 2 stops with the red filter.

The filter does increase the contrast but doesn't affect the sky in the way I have always been lead to believe a red filter 'should'.

I did have some success though with using a red filter and a polariser.

I also can do tricks in the darkroom to increase the contrast in the sky but it's not on the negative so to speak e.g. I can do some split grade printing and then some dodging and burning and get the result, but I just have this nagging feeling some people can take photos of nice contrasty dark skies on the negative itself with just a red filter -- or so what I have read over the years implies, maybe I have read that wrong and the dark skies do indeed come from the printing process.

The question is, am I doing something wrong?

I have gotten black skies with IR film easily but I don't want the IR look for the shots I want to take.

I'll be shooting with Ilford FP4+,

Thanks, the very amateur 😉
Vicky

 

[kully]

EDIT: I am going for a little lie down, and a little gin.

 

[mr_phillip]

I use a blue filter to get black skies - I'd always assumed you chose the colour of the filter depending upon what colour you wanted darker.

Umm, never heard that one before, but if it works for you then that's great. It's entirely contrary to the laws of physics though.

Vicky, the first thing that jumps to mind is that, if you're only allowing two stops compensation, then you're underexposing all your shots. The filter factor for a 25A is 8, which translates as three full stops. You might also want to experiment with different makes of filter. I tend to use B+W filters, and have no problems getting dark skies with red (and even orange) filters.

 

[kully]

Mmm..

I think I need to think before I write.

 

[telenous]

Sometime ago I bookmarked the following thread with similar content: http://www.rangefinderforum.com/forums/showthread.php?t=39210

Jocko in post #2 gives a good account.

 

[mr_phillip]

Hmmmm Gin... 🙂

Y'know Vicky, your problem might just be one of expectation. If you're looking to get black skies, then you'll really need something a bit stronger than a 25A (although the 25A + polarizer is a perfect solution). What you'll get with a red filter is more a darkening, with clouds standing out more against the sky, and a greater sense of drama. You certainly won't get IR levels of deep black though.

Have you ever tried taking the same shot both with and without the filter for comparison? Might be worth a try.

Here's a fairly representative shot using a Tiffen red filter:

 

[Lilserenity]

Thanks for all the responses.

If I am underexposing, then that probably does not help! I don't know where I read that for a red I should factor in a 2 stop difference, (1 1/2 for orange, and 1 for yellow) -- but I'll give it a go with a 3 stop compensation.

I don't mind using a polariser and a red filter to get the effect as I know it works, I just have never read anywhere that a red filter + polariser is the best way to get the desired result.

I generally never shoot into the sun so it's always behind me.

I have tried with and without and the result is much contrastier foliage but not much difference in the sky.

An example of what happens would be say this shot with just a red filter:

Telscombe Village (Ultron 35mm, Acros 100, Hoya 25A, Xtol 1+0 9mins or something)

Yet when I add a CPL with the filter:

Back of Downlands Business Park, Worthing (Canon 50mm, PanF 50, Hoya 25A, CPL, Xtol 1+0 not sure of time, 7-8mins I think)

I think because a RF is not great for using a polariser and the fact I had never read using a polariser with a red filter for best effect I was assuming I should be able to get contrasty skies with a red filter alone.

I'm thinking of using an orange filter + CPL then (I don't have a linear polariser, not that it matters) then this weekend with some FP4+

I did also wonder about grey cards but I get good exposures with my current methods on the whole. But for those more considered shots, maybe this might be a good idea?

Failing this, I'll look into B+W filters.

I don't want the look on all pictures but sometimes it can really work a treat and despite years of shooting black and white I feel a bit of a numpty asking such a question but I might as well be honest with myself and find out the answers to 'silly' questions 🙂

Vicky

 

[c.poulton]

You could try and use a different film? I swear by Ilford SFX 200 with a deep red filter for darkening blue skies.

 

[Al Kaplan]

If you're judging results by looking at pictures in old books, from back when shooting B&W film was the norm, consider that many of those films didn't have the sensitivity in the red part of the spectrun that roday's films have. So called "orthochromatic" films have no red sensitivity to begin with. They were available in 35mm and 120 sizes at least well into the 1950's and fairly common in sheet film sizes into the early seventies. Portrait photographers liked them for the "healthy" tanned look on men. Those films, together with a red filter really darkened blue skies!

Get an incident exposure meter. It's a lot easier than playing around with a grey card.

 

[notturtle]

Vicky,

Filter factors are a guide and the amount you need to apply depends very significantly on the colour of the light and where you want values to fall. As you know, a red filter darkens blue/green and so if you are shooting in the shade with a deep blue sky there will be more blue about and so more exposure would be required to get the 'right exposure. Shoot red/orange sand dunes and apply 3 stops with your red filter and you will end up with well overexposed sand dunes. In such a case you can apply far less compensation as the dune colour passes thru the filter, allowing for very deep skies.

The number 25 filters will not generally give black skies. Thats the preserve of the #29, which is a lot deeper.

I am quite confident that underexposure is not the issue here. If you expose more you will get more density in the blue sky areas, right? I think it is likely just due to the use of a not deep enough filter and the type of scenes shot. To get black skies even with a 29 you need to ensure you do not give too much exposure and that of course impacts on the shadows, so IMHO the use of deep reds tends to work best with scenes with deep blue skies and without particularly deep shadows, because then when you expose to allow the sky tones to drop out you wont lose too much of the shadows. You will likely end up with fairly deep shadows though.

FWIW, I experimented a lot with #29s and concluded that the look could be rather gimmicky, but I do keep them about in case the scene suits, and that usually means modest contrast along with very blue skies as I say.

A lot of filter factors are an 'average'. For example, B&W gives a full stop (factor 2) for their standard yellow. Tested against a light box with three cameras gave about 1/3 - 1/2 a stop. The orange red was rated at 2 stops. I found 1.3 - 1.5 stops more accurate and due to using cameras with 1/3 stop lenses or exposure comp, I give 1/3 and 1.3 stops for these and get negs with a variety of films that hold about the same exposure and shadow values as without the filter. These 'real world' factors were determined the hard way, with lots of film and testing and they work. I had horrid problems when using the 'recommended' settings. however, were I to shoot at altitude, where there is a lot of blue light, such as up mountains, I daresay I would need to give a little more compensation to preserve the shadows. However, as I was using them, giving too much compensation was contributing to the problems you mention.

Do not rely on internal TTL metering with the filter in place for anything past an orange or orange red as the meter is likely to prove more sensitive to the red light than the film. My Leica gives a healthy exposure about 2.5 stops down with a #29 in place, but it needs about a stop more than that.

One often finds that where black skies are evident on shots with #29s, the true blacks exist in even expanses of sky empty that have been burned down. if you shoot cloudscapes this is obviously not readily possible without killing the delicate clouds, although pre-flashing and then printing a harder grade might help squeeze the best blacks possible while preserving highlight subtlety.

 

[Pablito]

If you are metering through the lens using the camera's built in meter then you don't have to apply exposure compensation as you would with a hand held meter. (This may be obvious but it's not clear how you are metering.) But some exposure adjustment may still be required as described in post #10.

You need to use the very darkest red filter and you need to use it on a day with very deep blue sky to get the "day for night" look. (As others have said.)

Grey card is much cheaper than an incident light meter!

 

[Sparrow]

A red filter only looks red because it’s blocking it’s complementary shade, it is blocking the green wavelengths not blue. You will get the maximum effect on a blue sky by blocking the blue wavelengths with a yellow or yellow-orange filter of the same k factor

Assuming panchromatic film that is.

 

[bmattock]

You are not underexposing, you are overexposing.

If there were clouds in the sky, you'd catch the problem.

You are probably metering through the filter, which would give you 'middle tone gray' if you metered the sky, and then adding two stops of exposure, which is blowing your sky out and turning it white. Overexposed.

Either meter through the filter or meter without a filter and then compensate for the filter factor.

Bear in mind that if you meter the sky, you're going to get a middle tone gray sky. If you want a darker sky, meter something else in the scene that is closer to middle tone gray. Or just don't compensate for the filter. This will create an underexposed sky and it will indeed be 'dark'.

The most effective skies using a red or orange filter are those which have light white fluffy clouds in them. These become dark foreboding storm clouds, and the sky indeed goes black.

It's a fun effect, sometimes overdone.

 

[Lilserenity]

I should have mentioned how I meter.

I use my Leica MR so it's not TTL and I tend to meter the ground with a small amount of horizon (a 70:30 split biassed to the foreground I guess) so any compensation I do is really in my head.

The pictures always come out well exposed, just not with the expected result I guess. I'm also using films I use and know (ie: FP4+, Tri X and Pan-F -- not really got into Delta 100 or TMax yet) so I know them pretty well.

I think I shall look into getting a yellow-green filter for use on my Ultron (when I get it back) and possibly an orange too, and play with some FP4+ and a polariser and see what happens.

I don't want the sky black in all pictures, but as noted previously all I have read is red filter = black skies etc, when all I have gotten is some fairly good skies on occassion with very contrasty (as you'd expect) foreground.

This has been interesting. I have been wanting an answer on this for some time because I was curious as to what I was doing 'wrong' but its sometimes quite intimidating to ask when you have been supposedly doing this now for a few years!

Roll on some good skies this weekend then! 🙂

Vicky

 

[Roger Hicks]

Dear Vicky,

Consider also the point that a deep blue sky at 2000 metres in the mountains is a lot more blue than the average blue sky in Worthing. Geography, elevation, direction relative to the sun and weather are all important.

So is film sensitization. As someone else pointed out, many modern films are 'hyperpanchromatic' and much more red-sensitive than the old 'pan' films, so a given level of red filtration has less effect.


Cheers,

Roger

 

[Lilserenity]

Dear Vicky,

Consider also the point that a deep blue sky at 2000 metres in the mountains is a lot more blue than the average blue sky in Worthing. Geography, elevation, direction relative to the sun and weather are all important.

Good point Roger 🙂 Worthing itself isn't exactly known for its mountainous streets (well it's complete flat apart from the northern flanks) -- even the South Downs that it backs on to are not exactly high promontories compared to some of the climbs in Snowdonia, Lake District and the Pennines 🙂

So is film sensitization. As someone else pointed out, many modern films are 'hyperpanchromatic' and much more red-sensitive than the old 'pan' films, so a given level of red filtration has less effect.

This is something I have no experience in except for an old book I have from the early 60s which pays some reference to orthochromatic fillm and panchromatic but by the time I started taking this seriously, orthochromatic had been pretty much dead for a long long time 🙂

It's good to know there is always lots to learn!

Vicky

 

[Sonnar Brian]

Nikon R60 filter, 55/2.8 Micro-Nikkor, DCS200ir (Near-Infrared DSLR)

Not black sky, but looks darker as there is a lot of exposure for IR from the ground. A lot of those dark sky photo's are IR.

 

[BillP]

I've always found that a clear winter sky works best. M2, DR Summicron, yellow filter, Kodak 400CN. Guildford High Street, if you are wondering.

Regards,

Bill

 

[charjohncarter]

Maybe you are overdeveloping and also underexposing. Filters are tricky, you give up something every time you use them. You have to have everything correct for them to work: proper exposure with the filter in place, proper development for your FILTERED negatives, you have to know what you are metering, and with everything else you have to know if your filter factor is right for all the above. Personally, I would rather try to figure out flash guide numbers than filters.

 

[charjohncarter]

OK, here is one that I took recently is blazing sun at Santa Cruz, CA: orange Leica filter, TmaX100 at EI50, developed using Ansel Adams compensating development (HC-110). Mostly, I find that these darkening filters have to have sky as the most important reason for using them.