Here’s a quick update on things.

I got the Bronica, it turns out though it’s an ETR, not a newer ETRS. Not a big deal I suppose, but it wasn’t what was advertised. The shutter speed dial does not click into each speed setting like it should, but it still works for setting the speed. There was an exposed roll of film in the camera when I got it, but the pictures were junk. I put a roll of film in it to make sure the camera works. Once I get that roll back from processing, I’m probably going to sell the camera. It’s not all that much faster than the Rolleicord to use, and the maximum shutter speed is still only 1/500 of a second, which is pretty limiting. I’m going to try to get a Mamiya 645 AF instead. That camera has (mediocre) autofocus and a focal plane shutter with a maximum speed of 1/4000 of a second. The 645 AFD and newer models are also compatible with digital backs, in case I win the lottery and can suddenly afford a $10,000 camera accessory.

The light meter is still on my back burner. I don’t have a ton left to do on it, but I just never seem to have enough time to do a meaningful amount of work on it in one sitting. We’ll see when I finish it.

In more exciting news, I finally got a check from my totalled Volvo XC90, some of which I decided to put towards upgrades on my BMW 535xi. I purchased an Evolution Racewerks charge pipe with blow off valve, and a JB4 piggyback ECU tuner. FedEx and UPS say both shipments should arrive on Thursday. I’m looking forward to installing everything.

So I bought another camera yesterday. It’s a Bronica ETRS. I was looking for a medium format camera that’s quicker to operate than the Rolleicord. I thought an SLR style camera would be the way to go, and I stumbled on the the 645 format Bronicas. Here’s the sole picture on the eBay listing for the one I purchased.

It seems to be in excellent condition. It has a slightly damaged 75mm lens, which I’ll be replacing with a newer version anyways. It has a 120 film back, which is great because they cost about $150 on their own. The AE-II metering prism viewfinder costs about the same separately, too. Including shipping and some eBay Bucks discounts, I snagged this for a tad over $200, which is a pretty good deal. I’ll probably be adding the speed grip to the camera, making the handling experience very similar to a 35mm SLR.

The ad said it was untested, but it seems so nice that I’d be surprised if it didn’t work after installing a fresh battery. And even if it turns out to be a dud, I can probably make my money back by selling the parts individually.

I’ve made a small change in my exposure meter design. Rather than using one set of buttons to increase or decrease the shutter speed or aperture, I’m going to use one rotary encoder for each. I realized, as I was going to make a menu system for changing the ISO, shutter speed or aperture mode and perhaps one or two other items, that I really had no idea what I was doing. I found a few different menu setups for Arduino on forums and other places, but I didn’t really understand them because I don’t have enough experience. I thought it would be better to not use elements I don’t have a firm grasp on.

So instead, I’m going to use one rotary encoder each for changing the ISO, shutter speed and aperture. The encoders also have a built-in button, so I might use that to trigger the reading of the light sensor. I might also use a separate button for that. I haven’t decided yet. Either way, having a separate device to manipulate each variable should make the coding simpler.

Update on the exposure meter

The parts for the exposure meter came in last week. It seems that everything works just fine, except for the breadboard I picked out of the pack of 3 I ordered. It seems like the lower half of it does not work. Hopefully the other two are better.

Anyways, these are the major parts in the system:

  • Adafruit Mini Metro. This is an Arduino-compatible, ATmega328-based microcontroller. It’s the brain that processes the input from buttons and the light sensor and displays everything on the display.
  • 128×64 OLED display. This seemed like a good choice for this project because the OLED displays are easy to read in bright light, and I’ll be using this thing outside most of the time.
  • TSL2591 light sensor. This senses the light and gives the microcontroller somewhere to start when deciding what shutter speed or aperture to suggest.

So far, I have a set up that does the following:

  • Reads the light sensor and returns a value in lux.
  • Plugs the lux reading into an equation to get an exposure value.
  • Plugs that exposure value into one of two equations:
    • One equation finds a shutter speed that works with a selected aperture.
    • The other equation finds an aperture that works with a selected shutter speed.
  • Sends the lux reading, exposure value, selected ISO, and the computed shutter speed or aperture to the display.

Now I need to create a menu system for adjusting a few settings, such as the ISO, changing the mode from shutter speed to aperture and perhaps setting a minimum shutter speed or aperture value. I also need to come up with a way for the results from these equations to get rounded to the nearest third of a stop so they’re easier to use. That might be the trickiest part, but I guess I’ll come up with something.

Sunday in the Park 2018

Today I took a trip to Lime Rock Park in Connecticut for their annual Sunday in the park car show. I suppose it’s actually called a concours d’elegance, but to me it’s just a big car show with a few extra-fancy cars. Every labor day they make a whole long weekend of events featuring classic, vintage and antique cars at the track, with racing on Friday, Saturday and Monday. Racing is not allowed at Lime Rock on Sundays, so they have a huge car show, with cars lined up all around the track.

The highlight this year were the 50 or so pre-war Bugattis. They’re not really my kind of car, but it is really neat to be able to walk right up to these cars, which are probably one of only a handful of their type in the world and are worth millions of dollars.

Anyways, here are the decent pictures I was able to take. It’s tough getting a nice picture of a car at an event where there are thousands of people milling about. The cars were a little more spread out than they are at the Hemmings events, so that was nice. The pictures are in a Flickr album, so if buttons to scroll through don’t show up, just click the image to see everything on Flickr.

Lime Rock Sunday in the Park 2018

Parts are on the way

I placed the order for all the parts I should need to create my exposure meter. Most of the parts are coming from Adafruit, and most of the supplies are coming from Amazon. The total bill was around $170, but I had to buy some supplies and tools that will be available for use on future projects.

The main parts in this build are an Adafruit Mini Metro, TSL2591 light sensor and a monochrome OLED display. The Mini Metro is an Arduino-compatible microcontroller. It’ll take inputs from buttons and the light sensor, interpret them, and then show the results on the display. The light sensor will give me my light reading in lux, which I can then plug into a formula to solve for either the correct aperture or shutter speed. The OLED display should be pretty easy to read in a bright area. Plus I’ve wanted to use one in a project for a while. Other parts coming aboard are three buttons, an on/off button and some 9 volt battery connectors.

I had to buy some supplies for this, because it’s been quite a while since I’ve build something. I needed more hook-up wire, jumper wires, and breadboards. I also got some jumper wire pins, wire housings and special crimpers to put them together so I’ll end up with a more elegant package of wires at the end.

The Amazon stuff should be in on Monday they say. The Adafruit things don’t have an estimate, but I’d imagine they’d be in by Wednesday because they’re only traveling from New York City. Hopefully next weekend I’ll have a working prototype done on the breadboard.

I’m going to build a thing!

I currently have in my possession four cameras of different types (five, I suppose, if you count my mildly broken Canon AE-1), one of which is a Rolleicord. For those of you who don’t know, a Rolleicord is a TLR, or twin-lens reflex, camera, which means it has two lenses. The top lens provides the image for the viewfinder, and the bottom lens exposes the film. This was a common setup until the 1970’s when SLR (single-lens reflex) cameras became cheaper.

I bought it because it was probably the least expensive way to get started with medium format photography. As you can see, the 6x6cm image created by this camera is significantly larger than the 35mm that most people would consider normal, and it’s enormous compared to the APS-C size image sensors in many digital cameras.

I really like this camera, mainly because of the images that come out of it. The pictures have a quasi 3D feel to them that 35mm film and digital just don’t. It’s fairly easy to take candid pictures with this camera thanks to the top mounted viewfinder and extremely quiet leaf-style shutter. Since you have to look down into the viewfinder, most people don’t realize you’re taking a picture.

The main issue with the camera is that the picture-taking process can be slow, especially if the lighting conditions are changing. There is no built-in exposure meter, so you have to supply your own. I’ve been using an app on my phone since I got the camera, with totally fine results. The app imitates an old-school analog meter though, so the result it displays is kind of “fuzzy.” It gets the job done, but a real exposure meter would really add some convenience.

I have a car show coming up on the long weekend, so I thought I might order a cheap one on Amazon and give it a shot. Turns out, there really aren’t any cheap exposure meters out there. I was hoping for something around $50, and I’d even take a used one, but there doesn’t seem to be anything in that price range.

It finally hit me today that I could probably make my own exposure meter with more features for less money than I could buy one. I really love making things rather than just buying them if I can, even if it doesn’t save much money.

For this project, which has been done a couple times before according to the internet, I’ll use an Arduino to read a TSL2591 light sensor and show the results on a small OLED display (I’ve wanted to use an OLED display for ages). I’m not totally sure yet how I’m going to change settings on this machine, but I’ll come up with something. I’ll draw up a case for it in SolidWorks and then 3D print it.

I’m pretty excited about this, because it’s been a while since I’ve built a thing. I’ll try my best to post some updates, but there will definitely be one when the whole thing is finished.

So I discovered another capital region car show the other day, and just in time. For this season, I’ve been trying to attend as many car gatherings as possible. I’ve probably spent most of my car show time at the Hemming’s Cruise-Ins in Bennington, Vermont. The last one of those was Thursday, so I was looking for other shows to attend around the area. Luckily, I stumbled upon a Cars and Coffee type event dubbed Cars and Caffeine just a couple days before it was scheduled.

I don’t know how I hadn’t heard of this event before, because it’s pretty large. A couple of blocks of River Street in Troy are closed down and there is a diverse collection of cars displayed on the street. I believe this event is hosted by a custom shop on River Street called 1945 Speed and Custom. They had their shop open and it seems that, like the show, they work on a diverse array of cars.

I only got a couple digital pictures worth sharing, but I went through a roll of Fuji Superia too, so I’ll have to see how those came out later this week.

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