Big 'white' splotch in photo

[AlwaysOnAuto]

I hope you'll be able to see the 'white splotch' in the middle of my photo when I up load it.
I was using my Nex-7 with a Fotodiox Nik-Nex adapter, a Kenko NT Varaiable AUTO Teleplus 2x-3x adapter and my Micro Nikkor 55mm lens. There appears to be, on my monitor, a white splotch, for lack of a better description, in the middle of the photo image.

I know the 2x-3x adapter is causing it because I don't get one when I remove it from the equation.

Can anyone tell me why this is happening?

The 2x-3x adapter was relatively cheap so not using it isn't going to break my heart or wallet. It appears to be clean and not damaged in any way.

Thanks in advance for taking the time to look and comment.

[DanK]

I'm guessing--only guessing--that this is reflections between an element of the lens and the adapter. Why this is happening with such subdued light is puzzling.

[xpatUSA]

Here's the area with mucho contrast and saturation applied, then cropped and upped 300% nearest neighbor:



Nothing like a good pixel peep but I'm still baffled. I see hue shifts though and a slightly irregular shape. I would go for a coating problem in the Kenko:

1) fungus
2) bad coating when made
3) contamination applied when assembled
4) contamination applied by owner

[AlwaysOnAuto]

I think I'm going to go with Dan on this one Ted.
When looking at it naked, no lens attached, I can see a distinct circle on the element, like it was reflecting the back element or something.
I haven't applied anything but spit and polish to it, so I know #4 is out in your list. #1, I don't think so, it looks pretty clean to me. #2 & #3 I'm sure apply since I don't think there's any coating at all on it.
I'll have to try it on another lens and in bright light. I don't remember it being a problem when I first tested it upon receiving it.

[AlwaysOnAuto]

Here's an admittedly feeble attempt at a shot of it.



You can kind of make out the circle I'm talking about.

[tao2]

Hi Alan,

It looks (tae me) like lens separation, where individual elements begin tae come apart due tae glue failure, age, mishandling etc. Normally the first two. If yer able tae handle the lens itself, it'll be obvious. Ye'll see the separation. It has the classic, bright reflection but this is normally evident from the front of the lens.

The lens coating usually produces this reflection (from the air/glass separation), and suppresses any other reflections. This reflection, negates the anti-reflective coating on the lens and results in the lower contrast and increased flare, obvious in your photos.

As a connoisseur of cheap lenses, ah'd say it's a combination of an, initially, not very well made lens x age (and possible ) mishandling. They can be repaired and there's lotsa DIY repairs on the web but is it worth it?

[AlwaysOnAuto]

I believe you are correct Boab. It's an old lens and may have just decided it was time to come apart. I may just use it for really bright light situations as it doesn't show up as badly under those conditions.