Dark Skies W/O Filter

I've been shooting unfiltered Tri-X in the bright sun of the Southwest and I'm getting very dark skies, as if I was shooting with an orange or red filter. This is happening in mid to late afternoon, with skies that are very blue. The only way I can print these pictures is by using short exposures and very low contrast grades, but of course this tends to make the rest of the picture problematic. Can someone explain this phenomena? Would another b&w film alleviate this problem?

Critical is the film sensitivity to various parts of the visible spectrum, in this case the red portion. Switching films with different spectral sensitivities could resolve the issue somewhat. High contrast scenes usually compromise one part of the spectrum over another. I'd question using a fast film like Tri-X in the bright sun of the southwest, without at least a ND filter anyway, it seems to me that a slower film would offer a greater range of tones.

I agree that Tri-X may not be ideal for your scenario(that's painful for me to say).

 

I'd probably give my second favorite film-FP4+-a shot...

 

This is also one of those situations where I think TXP-320 would perform better than TX, but if you're shooting 35mm you're out of luck on that.

Photographic film uses salts of sliver as the light sensitive agent that captures the image. These are silver combined with one of three elements (iodine, chlorine, and bromine). These are members of the halogen family of elements. This family is called the halogens. The name is Swedish for “salt maker”. The three salts of silver are only sensitive to the violet and blue region of the spectrum.

 

 

Early films suffered from a degrading phenomenon, a halo like effect surrounding bright objects. This is caused when the lens passes bright rays from gleaming objects. These can transverse the film, hit the pressure plate and ricochet back into the film from the rear. Professor Vogel, Berlin Technical, trying to solve, dyed a film emulsion yellow. This solved the halation problem plus, to his surprise that emulsion gained sensitively to green the year was 1837. He named the film orthochromatic Later his graduate students produced films, using dye, that recorded, blue, green and red light. This film was named panchromatic.

 

 

Modern black & white and color films are now trimmed as to their sensitivity to different colors by means of what are called “sensitizing dyes”. Since the early films were only sensitive to violet and blue, often subjects reproduced quite weird. This was also true when using orthochromatic film. The high sensitivity to blue yields the blue sky near D-max on the negative resulting in white sky when printed. Ladies cheeks and ruddy complexions often reproduced nearly or truly black.

 

 

Filters to rescue: Even when panchromatic films were the rule, photographers kept a gadget bag of colored filters used to alter how colors recorded. Most popular was the K2 (yellow-green). This filter was the rave to get “correct” monochromatic rendering. Orange and red were used to darken sky. A polarizing screen does this job also. Your question deals with how your skies reproduce. It’s likely the intermix of exposure, color sensitivity and developing and printing circumstances. You own the common law copyright maybe your unique pictures will grant you fame.

Edited May 5, 2018 by alan_marcus|2

In that light, I would be shooting a medium speed film, around ISO 100.

IMHO, Tri-X in bright sun practically turns a SLR into a box camera. 1/500 sec at f/16. Very little or no room for adjusting the exposure, without using ND filters.

 

How is the film being developed? I've seen Tri-X negatives with high contrast.

Try shooting tri-x in bright light with an orange filter F11 1/250. I am in Texas with a nasty bright summer sun and am happy with the results. Skies look just right.

Most of the time the problems I see with sky is that a bright mid day/afternoon sky appears too light when printed. That is why people use graduated ND filters to darken the sky. I don't see why shooting Tri-x at around 1/500 sec should create a dark sky. Some people seem to be suggesting that it is a failure of the law of reciprocity that is causing the problem when they suggest using a slower film.or ND filter. What would be the opposite of a grad ND filter to lighten the sky? Or, even sillier, mount the ND grad filter upside down so it darkens the foreground.

You could try a full CT blue filter - 80A or B.

 

Ansel Adams stated that a clear blue sky shot opposite the sun was a Zone V tone.

 

Maybe true in tropical regions, but definitely not where I live!

 

I'm really not sure why you'd shoot Tri-X with its extended red sensitivity in full sunlight either.

 

"Some people seem to be suggesting that it is a failure of the law of reciprocity that is causing the problem"

 

- Rubbish! Short exposure (high intensity) reciprocity failure doesn't set in until you get into fractions of a millisecond exposure time, and then the effect is to lower contrast, not increase it.

Edited May 6, 2018 by rodeo_joe|1

A properly exposed negative would render a blue sky as a zone 5 or 6. Usually people fight to get that back when printing blocked up negatives. So consider yourself lucky by accident. How does the rest of the frame look?

 

Please tell us more about how you exposed and developed the film?

Actually shooting Hasselblad SWC. Got into the Tri-X habit years ago. Now that I think of it perhaps the Biogon had something to do with it. Film processed at a commercial lab in Santa Fe (the only one).

Kudos to alan!

Here is the sort of chart old "how-to" books used to give for B&W with filters:

"Some people seem to be suggesting that it is a failure of the law of reciprocity that is causing the problem"

 

The data sheet says +1/2 stop at 1/10,000.

 

My fastest film SLRs I think only go to 1/8000-F4, F5, F100. I don't think I've ever gone there. The only cameras I have that go faster than that are the D1 series cameras, which pulse the CCD for 1/16,000.

 

Even at that, +1/2 would hardly be noticeable on a film like Tri-X.

OK, so tell me again. Which filter to use in this case?

I still think you might be well served by my initial recommendation-FP4+

 

Or, if you're shooting medium format, dig out some TXP-320.

 

Also, what developer/dilution are you using currently? It might be worth either diluting your current developer or switching to something that will give lower contrast. Pulling the film(EI 200 with reduced developing time) will also lower contrast a bit.

"OK, so tell me again. Which filter to use in this case?"

 

Blue.

A blue filter will lighten a blue sky. Or rather darken every other colour.

 

Incidentally, what altitude are you shooting at? A clear blue sky darkens considerably as you ascend above about 3000ft. I got unexpectedly dark (clear) skies when shooting in the Alps at between 1500 - 2000 metres ASL.

Great point. I live and shoot at 7000 feet.

"Great point. I live and shoot at7000 feet."

 

- There you go. The sky's pitch black at the edge of space!

We've actually had some sun and blue skies in the UK (wow!). So I took the opportunity to try the effect of an 80A and 80B filter on a blue(ish) sky.

 

Nothing, zilch, nada. Nothing really visible anyway; although it might be detectable through a densitometer.

 

I used a digital camera in B&W mode with the WB fixed to daylight. I wasn't going to waste time or film on such an experiment. The effect on Tri-X may be stronger, but I'm doubtful.

 

I'm 100% certain though, that by shooting a digital colour original, a very noticeable lightening of a blue sky could be achieved in an image editor.

 

Dodging the sky during B&W printing is another option, but this might well result in a visible manipulation artefact.

 

The 80A (or Nikon B12) is the strongest blue filter commonly available BTW. Tri-colour blue is only available as a gel I believe, and has a strong factor of something like 4 stops.

 

Here are the test pix:

With 80A filter.

 

Unfiltered.

Edited May 7, 2018 by rodeo_joe|1

Some people seem to be suggesting that it is a failure of the law of reciprocity that is causing the problem"

 

- Rubbish! Short exposure (high intensity) reciprocity failure doesn't set in until you get into fractions of a millisecond exposure time, and then the effect is to lower contrast, not increase it.

 

I agree. That is what I didn't understand - the previous suggestions that shooting at 1/500 sec (Tri-X) will get dark skies but shooting at 1/100 . sec will get normal skies. At least the suggestion to use a blue filter to lighten the dark sky is a good try.

Ooops! I think I got the captions swapped on those two pictures above. It just goes to show how little effect the blue 80A filter had.

 

I went back to the pictures and could just detect a difference in tone using the 'eyedropper' of an image editor. Levels 156 and 165 in sRGB space. Visually indistinguishable.

 

FWIW, here's the unfiltered colour original to show how blue the sky actually was.

The hue/saturation/lightness tool was much more successful in lightening the sky, but of course that won't work with Tri-X.

You need to look at the entire scene before you photograph it in terms of luminance values. The easiest way is with a spot meter, but, with careful work you can do it with any type of meter, including through the lens metering on single lens reflex cameras. What you need to do is establish the range of luminance you're trying to record. Make a reading for the shadow you want detail in, make a reading for a mid-tone, read the blue sky in the direction you're photographing and then the reading for a white you want to retain detail.

 

Now you have the entire scene - where is the reading for the blue sky in relation to the darkest shadow with detail a mid-tone, and the white with detail? In Zone System terms, the darkest shadow with detail would be Zone III, the white with detail Zone VII and the mid-tone Zone V. Since each Zone value corresponds to one F/stop exposure change, you should be able to map the scene to a gray scale and understand how the colors will be rendered as grays.

 

If you're using a view camera, and making exposures on individual sheets of film, you can adjust the final negative though development and expand or contract the tones. Unfortunately, if you're using roll film, you can't do that, but you can understand how tones will be rendered in the final print by understanding the luminance range. You can make some compensation in exposure if you're willing to lose tones in shadows or highlights - but, at least you'll understand where you're making compromises.

 

One thing you can do to better understand a scene in black-and-white is to get a monochromatic viewing filter. The filter is used by "flicking" it in front of your eye momentarily, and then back away. If you stare through the filter, your eye will adapt and the effect will go away. If you use a monochromatic viewing filter, it will allow you to understand the scene in terms of how colors are rendered as shades of gray.

 

Another consideration is to use a film with a longer tonal range. However, the characteristic film curve is not just the film alone, but the film+developer. The curve is generated by the type of developer being used acting on the type of film emulsion. There are long tonal range developers like Photographer's Formulary MCM-100. It can be used with Tri-X and Ilford HP5 for expanded tonal ranges. It is an expensive, 1-shot developer - but it is worth the money if you care about what you're photographing.

 

I used it exclusively for development of Super XX, and Verichrome pan. When those films were discontinued I used it with Ilford FP4 and Delta 100. One of the drawbacks beyond the price and the chemicals (that I'm sure the safety sallies will find scary) is the long development times.

 

Another approach would be to use D-23 because it is a semi-compensating developer. Either of the developers would allow you to give the film 1/2 to 1 stop more exposure with the ability to produce very long scale negatives.

 

Then you have the problem of how skillful you are in printing darkroom techniques and the type of enlarger you're using. if you're using a condenser enlarger, that's part of your problem. But, you can get around the higher contrast by using a low contrast paper, and split development with a low contrast developer like Selectol Soft and a Dektol in two separate trays. Start the print in the Selectol Soft and when you have tonality in the highlights, transfer it to the Dektol for a brief period of time to bring up the shadows and dark grays.

 

If you're using a condenser enlarger, you might want to consider making a slight modification by putting a piece of flashed opal glass or thin white plastic between the bottom condenser and the negative stage. This will have the effect of diffusing the light and lowering the contrast about 1/2 grade of paper. If you're skilled with printing, you could also consider contrast dodging which is using variable contrast paper and two separate filters - a low contrast filter and a high contrast filter. You would establish the exposure time for the highlights through the low contrast filter, and the remainder of the print though the appropriate filter (grade of paper). In printing you would dodge the higher contrast portion while printing the highlights through the low contrast filter, and then dodge the highlights and print the remainder of the print with the second filter.

 

You could apply a filter (as suggested by another poster) when taking the photo. Any light blue filter would lighten the sky while rendering the remainder of the scene darker (except, of course for neutral colors like browns, grays, whites, blacks, etc.)

 

Finally, you could ignore all of the above and simply be happy with the results you're currently getting...

Edited May 18, 2018 by steve_swinehart

"if you're using a condenser enlarger, that's part of your problem."

 

The slightly higher contrast given by a condenser enlarger is due the Callier effect, and is only really noticeable if a point-source lamp is used. This isn't usually the case, since most condenser enlargers use an opal bulb.

 

The difference between condenser and diffuser enlargers is greatly exaggerated in photo mythology. In practise it's easily compensated by a simple paper grade change - of 1/2 to 1 at most - or by slightly 'pulling' the print development.

 

However, changing the print contrast will make very little difference to the separation of mid-tones, which is where Arthur's sky density appears to be placed.

 

"Any light blue filter would lighten the sky while rendering the remainder of the scene darker (except, of course for neutral colors like browns, grays, whites, blacks, etc.)"

 

- I thought I just showed that even a quite strong blue filter has almost no effect on the sky tone.

 

"you can adjust the final negative though development and expand or contract the tones. Unfortunately, if you're using roll film, you can't do that,"

 

- Of course you can. You just can't adjust the development for individual frames.

Edited May 18, 2018 by rodeo_joe|1

I said that using the flashed opal glass would only lower the contrast by about 1/2 grade - you chose to ignore that in order to confect an argument, as is the fashion on the Internet.

 

Let me quote myself --

 

This will have the effect of diffusing the light and lowering the contrast about 1/2 grade of paper.

 

I put flashed opal glass in my D2V in 1971 and printed with the flashed opal glass for the next 15 years until I changed the head to a Beseler Minolta 45A which is an additive color (RGB) diffusion head using flash tubes as the light source in a mixing chamber. The difference between the flashed opal glass and the 45A head was about 2/3 grade lower contrast.

 

The lower contrast head allows you to shoot longer scale negatives. If you can give the negative more exposure, you get more shadow detail and retain detail in whites. I generally printed on the equivalent of #1 grade paper with the diffusion head as I could give the negatives about 1-1/2 stops more exposure and then use a long scale developer like Edwal Super 20. When that developer was discontinued, I changed to MCM-100. The extra exposure + long scale developer gives an effective increase of about 2 stops added scale to a negative. Almost unprintable with a condenser head unless you resort to split bath development using Selectol Soft and Dektol - and then you will still have to burn in some lighter areas.

 

In fact, a blue filter will make the sky lighter - you've proved nothing. I'd suggest getting a blue filter and trying this yourself. What is happening is the blue filter is passing all of the blue light and darkening all of the other colors except for neutral colors like grey, brown, black, white, etc. When the filter factor is applied for the exposure, AND you make an additional exposure compensation to raise the other colors to the gray tone you want them - blue is getting more exposure in relation to the other colors (shades of grey) as more light is reaching the film in comparison to the colors being filtered (darkened). That gives greater density in the negative to the blue areas making blue print lighter in relation to the other colors. But, you actually have to test the filters in order to understand how to take full advantage of them.

 

If you shoot outdoors, there actually is a lot of reflected blue light. Even shadows are filled with blue light from the sky. On color film or with digital cameras with the white balance set at 5600K (film daylight color balance), shadows often have a blue tint because of the blue sky. Green leaves will not go black even with a #47B filter as they are reflecting a lot of blue light from the sky. They will be rendered about Zone IV. I carry #8, #11, #15, #23A, #25, #29, #56, #58, #80A, #85, .3ND, .6ND, .9ND, 1.2ND, and polarizer filters in my camera case. After using them for 50+ years, I'm pretty sure, I know how all of them work.

 

I see that being pedantic is one of your strong points. Yes, you can adjust the development of an entire roll of film for a single frame - few people would choose to do that so for most people (other than you) that would not be a practical consideration. My apologies for being all inclusive and leaving out the rare chance someone would adjust development of an entire roll of film for a single frame.

 

You've provided NO help to the OP, you only choose to argue points with me - why is that? Nothing I've said is incorrect from a technical standpoint, it is proven photographic technology.

You go to the trouble of doing the experiment, and the results are just ignored.

 

Ah well!

your experiments didn't prove anything, at least from the examples posted.

 

I think because you did those with a digital camera, it may not have responded the same as film... too many variables. The blue filter seems to be on track, except the OP hasn't posted his example, so we have no way of knowing if his negatives were just under exposed or under developed. He just said it made printing difficult.

 

Ya cant make em drink the water Joe.

 

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