SEI Photometer

TVR

TVR

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May 28, 2011
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this is a first post on this forum have been looking at it for the past few months, to the point picked up and SEI meter, got everything working except the micro ammeter, i will sort that out later, question is the bottom two sales which are Aperture and in my case ASA film speed, they were almost unreadable but have made new scales Photoshop, how do they turn? they sit in a groove, i have the manual maybe i have missed something. if anyone can help it would be appreciated, another note awaiting delivery of an Epson R-D1, never seen one in the flesh but they do seem to have a loyal following
 
I've wanted one since I saw them written up in a book called "Exposure Manual" by Dunn & Wakefield. Its a very technical book on the design and construction of exposure meters and how they are calibrated and used. The Edition I first read was from the 1950s. The SEI looks incredible, but every one I see for sale is broken and very expensive. Someday I may buy one.
 
Neat, but unfortunately there is no more point in using them - back when they were current (up to the late fifties as a precision meter of its own, past the late seventies as a calibration reference), the method of visual comparison to the brightness of a spot illuminated by a light bulb of tightly defined characteristics driven by a measured current was far more accurate and less subject to drifting and ageing than the then available photo cells.

Nowadays, it is trivial to buy a long-term stable silicon photo transistor, but near impossible to locate any precision bulb (it is already a pain to get replacements for 16mm sound projectors, and these are much less discriminating than a SEI), even less so a matching one for your SEI. That makes them hard to fix if you don't want to make a complete science out of it - you'll have to recalibrate from scratch each time you have to switch bulbs.
 
:) thanks for the replies for the web site mentioned i have seen it.
need to find someone on this site that has one (SEI Meter) i still don`t see how the bottom two rings move, the aperture and ASA, does anyone know who to ask on this site ??

thanks
 
sei photometer

sei photometer

Hello, saw your post from three years ago regarding the sei photometer. I just found one also and it seems to be in good shape. One detail you need to know, it's designed and manufactured in Britain and they use the positive ground system there. Therefore, the battery should be placed with the positive side down when you insert it into the battery holder. I was able to get a regular alkaline battery to fit mine after removing the plastic wrapping. Unfortunately, the wrapping also acts as an insulator and the entire outside of the battery acts as a positive terminal. The lamp at the top of the battery assembly still works. It illuminated the photocell to max and pinned the micro ammeter. Luckily it didn't burn out. I solved the insulation problem by spraying the battery with several thin coats of clear coat spray paint. The problem now seems to be in the rheostat at the bottom of the instrument. I need to disassemble it and see if it works. I have digital copies of the instruction manual and also the repair manual if you are interested. I'd also like to hear from other photogs who have these vintage instruments.
 
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