Good morning! 👋 

It was basically a heat wave 🥵 last week. I might be exaggerating just a bit—but it did warm up! Which means I was able to get out and take some photos. 🎉 

I went with the Mamiya RB67 and Kodak Tri-X 400, but with an added twist…a Red #25 filter. More on that later. 😀 

Here’s what we have for today:

1. 🧐 Let’s talk about filters

2. 🧪 Dev report

🧐 Let’s talk about filters

When I went out to take photos last week, my goal was contrast. I wanted a lot of it. To start, I used Kodak Tri-X 400, which is a pretty contrasty film. But for that extra oomph, I used a red #25 filter. There are all kinds of different filters available for your lens. But let’s go through some of the main ones and why you might use it.

Red Filter

A red filter blocks out or reduces blue and green light, but allows red light to pass through uninterrupted. The affects the contrast of different colors in the scene. I particularly like using a red filter for black & white photography. Why? Because it causes blue skies to get very dark, giving you a very dramatic look.

There are also blue and green filters. They work the same way for their respective colors. And these filters come in different levels of intensity:

• Light Red (#23A)

• Medium Red (#25) - this is what I used and is pretty standard.

• Dark Red (#29)

Neutral Density Filter

A neutral density (ND) filter reduces the amount of light coming through and hitting your film. It does this without altering the color. Couldn’t you just increase the shutter speed or stop down the aperture to get less light? You could, but it’s important to remember that shutter speed and aperture affect other things besides light.

A good use case for an ND filter is taking a long exposure of a waterfall in the middle of the day. ☀️ You want to use a long shutter speed so that the water will be silky smooth instead of frozen in time. However, if it is bright out, you may find that even with a small aperture your image is going to be overexposed. This is where an ND filter can come in handy. It allows you to have your cake 🍰 and eat it too. You can compensate for that long exposure time by using the filter to reduce the amount of light.

ND filters come in different levels of intensity. The filter will say how many stops of light it reduces (1, 2, 3, even 10 stops)

Polarizing Filter

This is a very important filter. In fact it is the only filter that you can’t replicate in post-production. It filters out polarizing light, which is light that is vibrating in a single direction. Usually, unpolarized light vibrates in many different directions. But when light reflects off of smooth surfaces like, glass 🪟 or water 🌊 it becomes polarized and gives you that glare.

Sometimes we don’t want that glare reflecting off the water or off the glass window. A polarizing filter can help us reduce that. They usually can spin, allowing you to fine tune what light you want to block out.

They’re kind of light magic, you rotate the filter and the glare off the water just goes away 🫢 

How to compensate when using a filter

One thing you’ll notice with all of these filters is that they reduce light to some extent. You need to compensate for that when metering, otherwise you’ll get a underexposed image.

You can do this on any side of the exposure triangle, but I find the easiest way is to adjust the ISO setting on your meter or camera. Let’s take my red #25 filter as an example.

This filter reduces light by 2 stops. This means it’s cutting the amount of light coming in by half and then by half again. So you’re only getting 25% of the original light.

Since I was shooting Kodak Tri-X 400 at box speed, normally I would have my meter set to ISO 400. But since my filter is reducing light by 2 stops, I can set my meter to be ISO 100 to compensate (400 → 1 stop → 200 → 1 stop → 100). Now I will get a properly exposed image and I don’t have to worry about trying to adjust shutter speed or aperture. Just remember to change the ISO back if you take the filter off; otherwise you will have an overexposed image. 😱 

Step up rings

Filters come in different thread sizes to match the diameter of your lens. But having a different-sized filter for each of your lenses can be a pain (and expensive).

This is where a step up ring comes in. They’re like adapters, letting you use a filter that normally would be too big for your lens. The nice thing is they are cheap. Just keep in mind that you can only step up, you can’t step down. So be strategic with your filter purchases. If you have two lenses you want to use a filter for, get the filter to fit the larger lens. Then use a step up ring for the smaller one.

🧪 Dev report

Long-time readers will know that I like to provide the “recipe” I used when ever I develop black and white film. Unlike color film there are a lot of variables and it’s useful to see what was used. This way, if you like the look of these images, you can use this recipe when you develop.

• 🎞️ Film: Kodak Tri-X 400 (120)

• 🧪 Developer: Rodinal

• 💧 Dilution: 1+25

  • 19ml developer + 466ml water

• 🌡️ Temp: ~68º F

• ⏱️ Times:

  • 🧪 Dev: 7:00

  • ✋ Stop Bath: 1:00

  • 🔧 Fix: 5:00

  • 🧼 Hypo Clear: 2:00

  • 🚿 Final Wash: 10 fill ups

• 👋 Agitation: 1 continuous minute then 10 seconds every minute.

That’s going to do it for this week, see you next week. 🫡 

Get out and make some negatives that you then turn into positives.

Ben Henschel

📷️ Canon A1 / 🎞️ Ilford HP5+