Noflexar remark and interesting mushroom

[Andrea B.]

The Novoflex 35/3.5 Noflexar has an interesting extension mechanism for close-ups. When extened, this lens can occasionally leak unwanted light. I'd say in my Noflexar usage, this leakage is definitely more of an unusual event than a regular occurence. Whether or not you get leakage probably depends on: the angle of the lens to the light, the amount of extension, whether or not your particular Noflexar is slightly loose in its fittings. The leak is easy to block - just wrap or drape the lens. I've never been able to decide if the shiny BaaderU plays any role in this or not.

 

The leaked light does not seem to affect a visible photo, but can be problematic in a UV photo. Here is an example.

 

D610-broadband + Noflexar 35/3.5 extended + BaaderU UV-pass

f/8-f/11 for 5" @ ISO-800

This is rather a long exposure for the given gear and ISO setting, but I was in a lightly shaded area and the sunlight had some cloud scrim.

 

The peripheral green ring is the artifact which occurs when the Noflexar is going to be light-leaky.

 

Unedited #6317

 

Edited #6318 in Photo Ninja

 

 

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As I was preparing the preceding mushroom photo so I could show you what the leak artifact looked like, I noticed something interesting about that mushroom. Go back and look at the 2nd photo. Can you spot the phenomenon? It is subtle.

 

Maybe this cropped view will let you see what I'm talking about.

This crop has not been resized. Do you see it?

Note: I am not referring to the doubled-edge evident long the stalk which is due to shutter slap.

I was not using a remote. I should have been using a remote. "-)

 

Here is one more view. Click it up to full size.

BTW, when I made this photo the Noflexar was not extended. This photo has no ring artifacts.

It was cropped but not resized.

[Andy Perrin]

Am I looking for an optical artifact or something real about the mushroom?

[Andrea B.]

There is a faint greenish-yellow glow around the mushroom. What is that? Is it some kind of reflection off the surface of the mushroom or is that mushroom glowing in UV? I cannot figure it out.

[Andy Perrin]

If the mushroom were fluorescing in UV (say), I would think the fluorescence would have a hard time competing with the direct reflected UV. Maybe light is scattering off the mushroom and hitting the filter at an angle, so you are seeing dichroic artifacts due to the off-normal scattering angle? Easy test would be to see if it goes away using filter glass instead of the Baader.

[rfcurry]

How magical is that mushroom?

 

 

[Andrea B.]

I don't think it is a dichroic problem because I've never seen this "glow" with the thousands of UV floral signature photos I've made. But anything is possible.

 

Further experiments are unfortunately delayed because the lawn crew sliced and diced all the mushrooms which had popped up after the recent rains. I never know when the lawn crew is going to arrive so was not able to save them.