antonio_piu

Thanks John, that's nice to hear. So, you think that also is a separation problem? Because that's another lens, it's not the same that shows the clearly defined arc shaped defect. These are two different lenses. I should have done a better job when posting. But here is a quick remark: first two pictures are about Zenzanon PG 50mm (shows pattern like droplets) - last two pictures are a Zenzanon PE 100mm (shows a discolored arc).

Thanks Conrad – I've only shot the one with potential separation as an adapted lens on my Canon 6D, so I have no way to judge whether it affects the image when used on my ETRSi. Do you think the beginning of separation on that peripheral point is likely to affect the final image on the 645 format?

Two of my lenses (one from my GS-1 system and on from my ETRSi system) show some issues in the glass, I'm providing a couple of pictures below. The PG 50mm shows something that looks like little dots or droplets, it would look like condensation, but it certainly isn't. The PE 100mm has a circular smudge, like an abrasion or discoloration. Both issues are only visible under direct light, and if I'm not looking straight into the lens, but rather tilting them on a side. What do you think those are? In particular, I wonder if the abrasion on the external circle of the PE 100mm might have consequences in the final image. Any help or advice is highly appreciated. Thank you.

By 'those', I meant 'those Sekonic L-758' light meters. I believe this is a good brand. I agree that aesthetics might not mean much. The information I was looking for was whether their technology was affected by time in a considerable way – from the discussion it seems like it isn't and that other factors play a much more relevant role in the end result.

I didn't really get what you meant here, probably due to the fact that I'm not a native speaker. I might be missing the metaphor. Thanks for your suggestions. If I were to follow this advice, I wouldn't even need to buy any digital camera as I own three. But I generally prefer to leave them at home whenever I decide to pick up my Bronica GS-1, hence my desire to get a dedicated light meter. Plus, there is a (probably silly) reason behind me willing to invest on something like that: it's an intangible benefit, a good feeling of actively learning something with the right tool. It even gives me the motivation to learn something new I'd probably discard if it wasn't for that "cool factor" :) Thanks everyone for your advice. I learned something for sure. It is my understanding that the model I had in mind (Sekonic L-758) uses Silicon cells, so – if anything – it should be among the ones with the best possibility to still be accurate over time.

Do light meters loose accuracy over time? I guess some technologies might be affected more than others. To be more specific: I was considering to buy a Sekonic with spot meter functionality. A model of the L-758 family would be perfect for my needs. I get that every tool will eventually stops working one day. But my question is whether it's relatively safe to assume that those light meters (which aren't cheap also on the used market) are working fine if their aesthetic conditions appear to be good. Is there any evidence that those light meters might be affected systematically by some decay in terms of accuracy as time passes, maybe be because of the specific technology they use or because of some known weak spot?