Making a HolgaFlex by Martin Blunden

Something I mentioned a while ago was attempting to fit an old large format lens onto a Holga 120 Pan with the aim of ending up with a 6x12cm shooting camera that takes reasonable quality photos on the cheap. (£100'ish in parts vs £1000 for a proper 6x12 camera)  There's a few guides on the internet but the most comprehensive one I found was this PDF which I pretty much followed to the letter, apart from one key point which turned out to be a rather major stumbling block.

Build

Finished Holgaflex (for now)

Focusing Problems

So the one major difference was that instead of the recommended Schneider Angulon 90mm lens I ended up using a much older Graflex Optar 90mm from the 1950s, mainly for reasons of cost, I'm not sure if the Angulons are extra popular at the minute but the cheapest I could find was in the £150 range where as the Graflex cost me £50. I assumed this wouldn't cause any problems, they are both 90mm large format lens so the same guide should apply right? Unfortunately this wasn't quite the case and I've had real problems trying to get the camera to focus properly without closing the lens down to f22.

I don't know if the flange focal distance / optical centre is different between the Angulon and Graflex lens but from what I can figure out the 12-17mm focusing helicoid along with the M42 body cap means that the lens sits 2-3mm too far forward, resulting in the lens not being able to hit infinity focus. I swapped out the 12-17mm helicoid for a fixed 7mm macro tube, and this had the opposite effect of moving the lens too close to the film plane. So I'm either back focusing or forward focusing and the only way to get a sharp image is to stop the lens right down.

In the images below you can see that with the 7mm macro tube the focus is off in the distance and the in-focus area moves forward as the lens is stopped down, where as with the helicoid at 12mm the focus starts off up close and expands off into the distance as the lens is stopped down, neither of which is ideal.

 

The two options are to try and extend the 7mm macro tube by a few more mm and have it as a fixed focus camera, or try and move the 12-17mm helicoid back a few mm which would mean chewing up the front of the camera. I'm undecided which way I'll go but its been a great learning experience, reading up on focal lengths and finally understanding how lens focus, that and its always fun cutting stuff up and trying to put it back together.

Thanks to Niamh for milling out the middle of the M42 body cap on the lathe, I blatantly would have made a right mess of it or lost a finger in the attempt.

Colour Scanning by Martin Blunden

Getting consistent colour scans has always been a nightmare. The automatic options in VueScan or Epson Scan end up giving each photo on a roll a slightly different look which in turn means lots of manual correction.

I decided to do some googling and came across two good tutorials which both work on the same principle. (Tutorial, Tutorial) You scan the negatives as if they were slide film so you capture the orange mask, you then cancel that out in photoshop, then invert the image and balance/contrast the colour channels. Its a bit fiddly to start with but seems to produce consistent results and gives you a great base for further tweaking.

I shot a roll of Portra 400 when I was down in Eastbourne the other week and just got the negatives back from the shop. Below are a couple of examples, including an accidental double exposure (I don't have an obsession with those life rings honest). It was an overcast day with no direct sunlight so don't think the colours are a million miles off.

I also rescanned some old film and ran it through the same process. The photos might be a little on the cool side but for a blanket setting its produced much better results than when I originally scanned this film. I think it was Portra 160

Eastbourne with a Pano Holga by Martin Blunden

and the start of another project

So my Holga 120 Pan arrived the other day, a bargain at £37 off ebay. Its a toy camera that shoots massive 6x12cm panoramic negatives. The lens is made out of plastic and is terrible, the body light leaks and the thing feels like its about to fall apart at any minute, but its a fun camera to use and a really cheap way to start shooting 6x12. A proper film back runs to around £300 and complete 6x12 cameras normally start around £1500.

The plan is to chop the front end off and mount a 90mm large format lens on a focusing helicoid. There's several examples online showing what other people have done and it doesn't look that hard. Just keeping an eye out now for a cheap Schnieder Angulon or a Graflex Optar then I can get started.

Below are some shots taken with the standard plastic lens, a fairly overcast day in Eastbourne heading along the prom and up onto the downs. Pretty happy with these for a first outing and getting used to the camera. Shot on HP5+ at box speed, developed in Rodinal.

Flickr Update by Martin Blunden

I've posted a few new pictures to my flickr page, mainly shot around Bishopsgate and Eastbourne. Taken with a Mamiya C330, Mamiya 654 and Olympus XA on Ilford FP4+. developed in Rodinal.

Pin Hole Camera Project by Martin Blunden

So I thought I'd have a go making a pinhole camera out of some foam card using the 4x5 film holders I had from a large format camera. A quick google turned up plenty of pinhole build websites out there for inspiration. I ended up using Pinhole Designer which is a pretty comprehensive program to calculate the various distances and measurements you need. I wanted a fairly wide view and according to it a 100mm Focal Length with a 4x5inch filmback would give me a 78° angle of view, which is roughly the equivalent of a 28mm lens of a standard 35mm camera.

  • Focal Length: 100mm
  • Film size: 4x5inch
  • Angle of View: 78°
  • F-Stop: 222
  • Optimal Pinhole size: 0.45mm
One of the first images taken with the camera. I think with a finer cut hole the image should sharpen up a bit from this,

One of the first images taken with the camera. I think with a finer cut hole the image should sharpen up a bit from this,