Challenge, don't know if it's the camera or the film/developer combo

[Anscojohn]

John,

Tri-x, Fomapan 200 and Adox CHS 100. The only time I'm getting grief, is with the two rolls of Plus X I shot recently.

*******
So you have shot film both before and after you shot the Plus-X?

 

[gainer]

Check your shutter speeds. Find a scene for which 1/25 @ f/11 is correct and shoot successive frames at that setting, 1/50 @ f/8, etc. If all the negatives look alike, you can rule out the shutter. If they are all wrong the same way, it's the metering or the processing.

 

[fhovie]

I would do a film test with your camera - put even light on a wall with or without some sort of item in the center and meter the light off the wall - set that as zone 5 and run your shutter up 5 stops (or combo of shutter and aperture) then with camera on tripod - shoot 10 frames from zone 0 to zone 10, each frame reducing shutter speed and then aperture making sure zone 5 is what you metered on your frame 6 (zero is the first frame) and develop. If you have shutter problems they will show up pretty readily. With a densitometer - I know I have hit the mark when zone 10 is at about 1.25 (I shoot MF and LF - 35mm might be better at 1.0) and zone 5 will be around .6 give or take a half. Base fog should be less than 2.5 (often around 1) unless you are pushing - you should see some densitometry changes between at least zone 1 and 2. It takes a little over an hour to do this test and then you can shoot with confidence in your whole system. If you do not have a densitometer - you can get step wedges and compare them by eye. That actually works quite well if you have some kind of small even light table.

If you miss the mark on your development time - you will see an even graduation but it will be too dense or too light at zone 10. If your camera needs service - you will not see a difference from zone 0 and zone 2 for the high speeds, trouble with zone 8 to zone 10 could indicate your low speeds are hanging. A good camera/film-developer system will be very linear from zone 1 through zone 9. Of course certain developer-film combos can cause compression at either end of the scale. I use a type of XTOL and tri x as my staple for MF and have found that this test is repeatable and helps me have confidence to get perfect exposures in the field. My light meter, my camera, my film, my developer, my thermometer and my clock are all on trial in this test. I do this with whatever film I choose to use and it has resulted in adjustments to development time of as much as 30%. In the end I get reliably exposed images.

 

[fhovie]

Oh yeh - one more thing - after about 10 years of playing around with film and developer I discovered that 80% of images could be best served with 20% of the film/developer combinations I was using. So I figured that with what and where I shot I would standardize on one combo. So now for MF - It is only tri-x and only my xtol compatible brew. One film - one developer - now I spend my time on the images and make a lot fewer mistakes. And as a bonus - If I do need ASA 1600 - I can use the same materials and just change my development time.

 

[clayne]

Maybe obvious or maybe not. But I'll assume that if you're shooting with PX @ 125 you're shooting in the daytime or outdoors - which is a typical condition for regularly stopping down. Then again you didn't mention flat skies and snow. Anyways, checked for oil on the blades lately? Or is it regardless of lens?