Orthochromatic film and yellow filter

pkr1979

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So, I shot two sheets this week with ortho film (same scene). One with a yellow filter and one without. Im assuming the contrastier one is the one with a yellow filter? Or is there any chance Im assuming this wrong because ortho?
 

Doremus Scudder

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You don't know which sheet is which otherwise, I assume...

So, let's see... Ortho film is sensitive to blue and green. A yellow filter blocks blue but passes green. So, a negative made with ortho film and a yellow filter should have darker blues and lighter greens (assuming that the correct filter factor was applied).

If your "contrastier" negative has darker blue skies (less density in the negative) and/or lighter green foliage (more density in the negative), then it would be the one made with the yellow filter.

Does that correspond to your results?

Best,

Doremus
 
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pkr1979

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You assume correct! :-D There is very little blue in the picture. The sky was mostly grey, and so was the sea. The green trees does seem to be a little denser in the contrastiest negative. There is also more distinction in the sky. Objects in the distance seems sharper on the one I assume is with a yellow filter then the other with a UV filter.
 

Don_ih

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Just don't use a red filter with the ortho film

Yellow will boost contrast, assuming you're not taking a photo of a yellow flower against a white backdrop (it might end up hard to see).

What ortho film is it? Ilford Ortho 80 is pretty high contrast on its own.
 

loccdor

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If your shutter speed is slow enough and there's water or other movement in the picture, you can also use the motion blur as a clue. Since you would have done 2x exposure time with the filtered image.
 
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pkr1979

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The shutter speed was half a second and a second (and half an aperture), but its hard to tell (also in regards to the aperture).

Its Ilford Ortho Plus indeed. The yellow filter really helps over the UV filter on distant objects.
 

Andrew O'Neill

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It will have a bit more contrast. I often use a yellow filter with green latitude XRAY film when shooting leaves, or want to separate clouds in the sky. I have even used a #25 red filter with success...but you must increase the exposure by at least 512x (9 stops)...making it not very practical. The resulting negative is quite contrasty, but may work fine for very low contrast situations.
 
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pkr1979

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Im considering xray film myself. Did you ever try Fuji HR-U or Fuji RX (RX-N)? I get that they got emulsion on both sides, but how much does that matter for contact printing?
 

Andrew O'Neill

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pkr1979 said:
Im considering xray film myself. Did you ever try Fuji HR-U or Fuji RX (RX-N)? I get that they got emulsion on both sides, but how much does that matter for contact printing?
Click to expand...

Some green latitude stuff from cxs-online, and I also have a box of HR-U, that I haven't tucked into yet. For contact printing, double-sided emulsion doesn't matter. You will only see a difference if you do a side by side with a single-sided emulsion...and it's a small difference.
 
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pkr1979

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Thanks!
 

Doremus Scudder

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pkr1979 said:
The shutter speed was half a second and a second (and half an aperture), but its hard to tell (also in regards to the aperture).

Its Ilford Ortho Plus indeed. The yellow filter really helps over the UV filter on distant objects.
Click to expand...
Yes indeed! The yellow filter will cut a lot of the haze and atmospheric effects. If that's the case, that's the negative made with the yellow filter.

Doremus
 
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