I recently decided to seriously pursue B&W, shooting Tri-X and developing in HC- 110. I picked up two filters for my B&W work, a #8 yellow and #25 red. The filte rs are Calumet's brand, which the salesman said are actually coated Hoya filters . I intended to order B+W but they were out of stock and being a few days away f rom an out of state trip I decided to go with the Hoya/Calumet filters.
This weekend we had a beautiful blue sky day so I decided to do some tests to se e the effect of each filter. I made three exposures of the same composition, one unfiltered, one with the #8 and one with the #25. I increased exposure for each filter according to The Negative: +1 stop for the #8 and +3 for the #25. After developing the negs and letting them dry I put them on my light box to evaluate. To my eye I can see almost no difference whatsoever between the unfiltered neg and the one shot with the #8. With the #25, I estimate the sky area of the neg d ropped in value, at best, about 1/3 stop. Definitely not the dramatic effect I e xpected from the #25.
The next day I decided to repeat the test thinking I may have forgot something s imple. Same result - a very slight reduction in the sky area with the #25 and no real detectable difference in the others. I'm totally perplexed as to why I'm g etting such negligable results with these filters. My color slides come out fine so I doubt the problem is camera or lens related. Because the negs otherwise lo ok pretty good I am at a loss as to the cause. I find it hard to believe that th e filters are the cause but lacking any other explanations I don't know what els e to think. There must be some variable I'm missing. Any body got any ideas? Tha nks as always!