analyse THIS! Flare testing the MIR-20M

[pst]

Hi!

This afternoon I finally took my "new" Mir-20 for a stroll. Since wide angles catch lot of stray light from everywhere I tested it for flaring.
I caught some nice shots, but found a nasty feature of this lens.

Flare must not be bad. I like this shot: [all EOS 5D]


But what really got me is the following:



See the lower right corner?
It only shows up at a very specific angle of sun relative to the lens and changes color nicely:



Up close:


But what gets me are the stripes and the circular imperfections. What could that be? Dust? Or wavelength imperfections of the glass??? The spots seem to stay in the same position in the picture.
Any opinions?

[LucisPictor]

The spots are dust particles on lens elements.
The stripes are some optical effect, I just cannot remember the term now.

[marty]

It's diffraction, occurs when a light beam hits an obstacle (in this case the iris). The smaller is the aperture the worst is the effect. The hexagon itself is a reflection of the iris on glass surfaces. A hood should tame the problem.

Cheers, M.

[ylyad]

I'd say it's a reflection of the sensor (hexagonal because of the iris), and the dust elements can come from the sensor itself.

[martyn_bannister]

[pst]

I knew where the hexagonal comes from

@ylyad and martyn_b: You are totally right!
The spots ARE dust spots an the sensor! I took a blank shot with my 50mm stopped down all the way and compared the spots! They match 100%, Yeah and the 5D likes to collect dust

This is so cool! You can actually see how the light bends around the dust on the sensor!!!!

The larger, not so clear spots must be from dust on lens elements.

The lines parallel to the iris edges are diffraction from the iris (I conclude this from reading wikipedia )

But what is the explanation for all the other parallel lines?

And the reflection itself: Thinking about it, it really must be a reflection off the sensor, because looking at it's shape, it has past the iris.

This is so cool, pixel peeping at it's best.

[egidio]

thats a nice looking flare

[martyn_bannister]

[William]

Quite like the Mir 1-B flare, seems both are very flare prone lenses. You have used it quite a bit more effectively than me:

[aoleg]

[martinsmith99]

That flare is very good compared to my Viv 19mm.

[soikka]

Just love the first shot.
I'm not used to using flare in my shots as I'm using mainly SMC-Pentax lenses .

Sigma 24/2.8 or Rikenon XR 35-70/3.5 might be the worst flare generators in y humble collection, but the flare with those lenses usually ruins the whole shot with lack of contrast in the whole image area. Have you PP'd the first image much?

[pst]

The Mir-20M does not seem to have to much coating, certainly not Super-Multi-Coated
All shown pics are simply converted RAWs in LR. No pp.

@aoleg: The engineers where thinking: "Why would you wan't to use a hood, when it flares so nicely?"

[pst]

That's what mine looks like. No "MC" writing and certainly no hood!