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SteveB
17th September 2009, 08:30 PM
I have just built a Negetta point and shoot (many thanks to Sandeha for the instruction/ plans). The negatives are thin eg under exposed, how can I check the shutter speed of my newly purchased ebay 90mm f6.8.

Dave miller
17th September 2009, 08:37 PM
My experience is that shutters normally run more slowly as they approach the time for a service, which is the opposite of what you seem to be experiencing.

Is the underexposure consistent across a range of speeds and apertures?

Sandeha Lynch
17th September 2009, 08:50 PM
Congrats on building one. :)

I've never tried this but I'm told it works ... http://rick_oleson.tripod.com/index-135.html - of course you'd first have to go out and buy a TV (maybe ;) ) Either unscrew the lens elements first, or place a sheet of tracing paper across the film plane.

Otherwise, reconsider your metering and adapt exposure to suit the shutter.

SteveB
17th September 2009, 08:53 PM
i think you may have indicated the source of my problem. I cannot use a sekonic meter correctly. I am completely at a lose with reflected and incident light and exposure generally. I will just bracket the exposure setting.

thanks for your help. Twice this evening! steve b

Akki14
18th September 2009, 06:45 AM
White bobble when over the sensor points *AT* the camera from whatever you're photoing. That's fairly accurate.

Reflected (no white bobble over sensor) can be tricked and fooled by bright white things or very dark things.

And of course remember it's set to the right ISO which I occasionally screw up and forget and lose 2 stops because I have it set to 400 instead of 100...

kev curry
18th September 2009, 10:43 AM
Scotland, or if this would be of any interest to anyone else, there's a very good and accurate home made device for testing shutter speeds... 'The Sound Card Shutter Tester'. I had/have no knowledge of anything remotely connected with electronics, and couldn't tell the difference between a resistor and a photo-transistor, but still I just followed the schematic drawing of the circuit exactly and hay presto! If youve never soldered before there's plenty of 'how to' videos on Utube to give you the basics. All together it cost me about £10er for 'all' the parts at an electronics shop.

Heres a link to the plans on how to make and use the tester.

http://www.davidrichert.com/sound_card_shutter_tester.htm