Sekonic spot meter problems

[Jimi3]

So I’ve just noticed that my Sekonic 478dr with 5 degree spot attachment is indicating that I expose about four stops over what my iPhone spotmeter app recommends. The app seems to agree with my digital camera meter, and when putting the Sekonic in incident mode, it is within about a stop of those two digital methods. I can’t find anything wrong in the settings of the Sekonic. It’s interesting, because I’ve found with both Rollei infrared film and with Ilford ortho plus, I’ve had to rate the film much faster than what most people indicate, so my first thought was just that the meter was off- I was in effect compensating for the overexposure indicated by the meter. This doesn’t quite make sense, though, because with other films like Arista, Frankenstein project, and Kodak Gold, I’ve been using the same spotmeter at the box indicated film speeds and have had good results. I just recently realized that this was a problem when shooting some Instax Wide on my 4x5, and seeing those instant prints come out WAY overexposed after using the spot meter.

I need to shoot a bunch of test frames to figure out which metering method to use, but I’m hoping someone might be able to help clarify what’s going on here.

 

[koraks]

I don't know how your Sekonic deals with detecting which metering attachment is mounted, but I know mine struggled with this: https://tinker.koraks.nl/photography/fixing-sekonic-l-358-and-np-spot-meter-wrong-readings/
See what happens if you press on the spot meter attachment while you take a reading. If this makes a difference, it's a similar contact problem that mine has.

 

[Jimi3]

You are correct! It takes a bit of force, but pressing in on the spot attachment brings readings more or less into line with what my other methods are showing. Thanks. Interestingly, mine is leading to massive overexposure rather than the moderate underexposure in your post. I’ll have to look there in more detail…maybe cleaning the contacts would help. As is, the attachment connection seems like it might be too unreliable to continue using.

 

[koraks]

I think yours erroneously "thinks" that the 1 degree attachment is present if you install the 5 degree attachment. This would explain the overexposure. It depends on which of the contacts malfunctions and how they're encoded. This may be different between your and my meters since they're different models.

I'm glad you at least have an idea of what causes this and a bit of a workaround. This is also how I presently use my meter, by just pressing the spot attachment firmly into the head while taking a reading. It's cumbersome, but it works.

 

[Jimi3]

So it sounds like cleaning the contacts clearly wasn’t a permanent fix for you. I wonder if I should even bother taking mine apart. Now that I know where to apply pressure, I guess it isn’t all that hard to make it work as is, and the display resets the reading every time I release pressure, so at least I can tell which reading is correct. I’m definitely not wanting to pay for a new spot meter.

 

[koraks]

So it sounds like cleaning the contacts clearly wasn’t a permanent fix for you.

Not entirely, no. Part of the problem appears to be mechanical, maybe fur to variations in molding of the different parts. It's just too loose a fit. I still want to go back and kludge something with a layer of tape or something, but since the workaround is pretty easy, I haven't bothered yet.