Wednesday, September 24, 2014

Alpha 1 vs. Model 1

I'm attempting to post via tablet so please bear with me if this turns out looking like total bananas.
Ok... I've had time to cruise online for some donors and "fixers" for sale, mostly on Ebay, and it seems that there's a TON of confusion regarding the identification of different SX70 models... specifically the tan/chrome models. I'll do my best to bust some myths (I've touched on this before but just a bit) and clarify some differences between SX70 Model 1 and SX70 Alpha 1.

First and foremost... what appears to be chrome or stainless steel is actually electroplated plastic. Early SX70 models have a brushed chrome finish while later models, specifically Alpha 1 models, have a matte steel finish. The only parts that were solid metal were on first generation Model 1s and Model 2s which was the aluminum shutter board... it can be seen when the film door is open under the shutter faceplate.
There are some exceptions though. I've seen some "transition" models that have both brushed and matte parts. Most often though, if the faceplate is matte, its an Alpha 1. It's impossible to replace a Model 1 brushed "chrome" faceplate on an Alpha 1 without modification.

How to identify an Alpha 1:

The film door ID plate - If it says Alpha 1, it's probably an Alpha 1. Though it's easy to swap film doors so check the other identifying characteristics below (as well as the matte steel finish on the body) to confirm. If it simply reads "SX70 Land Camera", it's most likely a Model 1. "Model 1" was never printed anywhere on the camera... it was always referred to as "SX70" until various models were produced.

Tripod attachment - If there's a hole on the bottom panel, that's a tripod attachment, it's most likely an Alpha 1. Model 1s did not have this attachment.

Strap clips - If you see these little bars on the rear of the camera, these are for connecting a strap. Alpha 1s had these. Model 1s did not.

Flash fill capability - While not a visual cue, starting with the Alpha 1 ECM substrate (circuit board) users had the ability to use flash fill in daylight shadow conditions. This was automatically determined by the camera once an electronic flash or flashbar was connected to the flash fire assembly. From what I've researched, all cameras have this capability with the exception of early Model 1 and some Model 2 cameras.

Focus lens scale - Early Model 1s simply had tic lines on the ring of the lens while Alpha 1s have distance increments. This isn't entirely reliable as some older Model 1s were retrofitted with numeric lens rings.

So why the fuss about the difference between the two? Alpha 1s are generally worth more because of the improvements Polaroid made with both cosmetics and electronics. From what I've seen, and often using these cameras myself, Alpha 1s offer better exposures, better fresnel viewfinder optics, and better electronics (more efficient and quicker motors were used as well). It's much easier to repair electronics on an Alpha 1... the later flex circuitry is so much nicer to work with as the risk of delamination while using a soldering iron is just about zero.
In a nutshell... Alpha 1s are awesome. Heck, all SX70s are fantastic! Just keep your eyes open before buying what some folks may call an Alpha 1. They're most likely not trying to rip you off but it will help knowing what to look for before you pull the trigger on a purchase. And of course if it doesn't work I'll be happy to fix it for you (shameless plug). Shop's closed!

Thursday, September 18, 2014

Repair Updates – Blame it on the Pickoff - Immaculate Ivory and Alpha 1

SHAME! Shame on me… shame on me a million times. I haven’t been posting like I meant to the past few months but I’m still here and still gladly accepting cameras for repairs. I’ve even found the time to post a few for sale here and there. In fact, this is the most steady amount of cameras I’ve had in quite some time – on average 3 cameras a week. I’ve also been building a new portfolio for my artwork. Times are a changin' and I need to be prepared to pick up and “go” at any time so I’ve been dedicating some more afterwork time developing and maintaining my artsy fartsy skills. Add a day job on top of that and weekend travel, that leaves about 8 hours a week for me to turnaround cameras. I’m not complaining at all though. It keeps me out of trouble… :)

I had some time to go through my inventory and see what I have as far as parts and donor cameras go and I realize that I’m getting low on a lot of common needed components. The 3 most common parts that I use right up are lenses (half of the submissions I receive are coated with fungus), motors (time takes a toll on these suckers… most can be reconditioned), and sonar assemblies which I’ll focus on in a bit. When I first started doing this repair gig as a hobby I’ll admit I had no idea what I was doing or how to efficiently go about a repair. If the autofocus wasn’t working, the natural thing to do would be to strip it off of a donor camera and *blam*… good as new. Well now I have all these components that have been stripped off of several other cameras and I can no longer just swap assemblies because even trying to find a good donor anymore is a hair pulling experience. So the next step would be to buckle down and learn how to properly repair a specific problem with the AF. I’ve been doing this the past few weeks… relying a ton on my multimeter and troubleshooting charts.

Most of the Sonar cameras I receive for repair have a common problem - they all only focus only between 3 and 5 feet. I’ve had one that just coasts… it can’t settle on a specific distnace, and I’ve had a few that jump their focus directly to 10.4” (also known as ringing). Those two were relatively simply fixes that require adjustments. However, the 3 – 5 feet only problem requires sleeves rolled up, music cranked up loud, a non-shakey hand, 3 hours of spare time, and a HUGE pile of patience. There’s a little component known as the “pick-off” or it could also be called the encoder sensor. This part essentially “counts” the number of holes on an encoder gear as it quickly rotates. The transducer sends off a “chirp” that bounces off the subject back to the camera and tells the gears to set in motion… the pickoff counts how many revolutions the encoder gear has turned and based on the subject’s distance, determines where the gears, in relation to the focal distance, should stop… now focused on the subject. I’ve gone crosseyed thinking about how this works but let’s just say the repair manual does a much better job describing the theory of operation.

Long story short (too late), these pickoffs can go bad after time and need to be replaced. I performed this procedure last night and I’m very happy to say it was a complete success!! Pickoffs can be tested on their own using a multimeter and I found that I have a ton of them in my parts bins. The transplant required quite a bit of disassembly of the Sonar components in order to unsolder the 4 wires that connect to the PCB board so having a good solder workstation is a must for procedures like this. I couldn’t imagine trying this with my 15 dollar Radio Shack iron. Reassembly was the biggest pain as the gears need to be held in a particular spot in order to secure the lever arm that adjusts the flash tilt as well as maintaining proper focal calibration. So there's a new repair that I can advertise!

*phew* I want to keep writing but I’m breaking my own rule that there should be more pictures than words. So I’ll just add that I also found a decent remedy for overexposed prints by removing corrosion from the photodiode located on the back of the shutter PCB board. Removing the corrosion allows more light to the photodiode which results in faster shutter speeds and less light being allowed for exposure. So now I’m trying to make it a habit to check the photodiodes for each repair. Although it’s more work and in some cases, with older cameras, there’s risk of delaminating a board it’s worth it in the long run knowing the camera goes back to the customer working properly.

We currently have 2 cameras up for sale on Ebay. Check em out sometime! OK… I’m done. Shop’s closed!

Here's a shot of the pickoff replacement in progress... final assembly is shown in the diagram.

Before and after of the photodiode cleaning...

These cameras are currently for sale and are in need of a good home!