A7 II and some Hexanon AR issues ....questions

[albaiq]

Hello from France, I use a NEX 7 with legacy lenses (AR Hexanon, Gottingen Isco, Lester A. Dine) with very good results (for me), I bought last Thursday an used A7 II  (like new 1295 € instead of 1700) on a French resellers website. I went to test my stellar 2/35mm Hexanon, to assess those results to its true focal. Returning, what a disappointment, in some photos overexposed faded spots appear randomly. Sunday I did a test on all my lens and the result is as follows: 35mm and 50mm Hexanon problems, Hexanon 24mm and all focal lengths 105, 135, 180mm no problems ; reflections appear when the A7  is at a certain angle to the light source .. My fear is having purchasing an A7 II with a defect (position of sensor) what do you think?

Should I think that the problem comes from my chinese (not enough accurate) adapter rings? Have someone experiment such problems, I have to decide do send my A7 II back or cry my Hexanon 35mm dream.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[addicted2light]

My guess is that the rearmost element in the two Hexanon generate a reflection onto the sensor. The other lenses probably have a smaller or deeper last element so are problem free.

 

Alternatively, it could be some kind of weird light leak from the adapter. Try shielding the part where lens and adapter meet with a rubber band or a piece of black electrician tape and test the setup with a powerful LED flashlight if you have one (they cost 3€ anyway), looking at the screen while moving the light around the lens mount.

 

Should the problem be the reflection from the rearmost element of your lens, like in my first hypothesis, you could always try to cut from a thin piece of black plastic a couple of rectangular masks and stick them somewhere to the back of the two troublesome lenses.

[f/otographer]

I think addicted2light is spot on in his assessment. I seriously doubt your A7 is at fault since it exhibits this issue with some lenses and not others. Definitely test your adapter for light leaks since many of them are cheaply made. I test my adapters by using a lens I know is light tight with a lens cap on and then point the lens at a light source (like the light fixture in a room on the ceiling) and then look thru the viewfinder. Move the camera in all directions so the light will spill across all part of the adapter. If you don't see any glow while looking thru the view finder then the adapter SHOULD be ok. But sometimes very small amounts of light can still leak in that wont effect a normal shot but can prove problematic with long exposures.

 

Other then that it may just be the design of certain lenses that cause flaring and ghosting to appear. Sometimes the old Tamron SP 90mm Macro would do this, which is a shame since it is a great old lens. But I have seen many nice images from the Hexanon 35/2 on Flickr so it may not be your lens. Also make sure you give the lens a really good inspection to make sure there is no fungus or small foreign elements in it. Put your eye up to the back of the lens and hold then it up to a light source. Rotate it around and change the angle of the lens against the light and you can see the small details inside.

[albaiq]

Thanks for your answers, I will investigate

[olemartinorg]

Digital sensors are more reflective than film, so when digital came out, they started re-releasing lenses with a D-suffix that had rear element coatings. I'm guessing your Hexanons don't have that rear element coating, so that might be why you see those spots (with the rear element bouncing reflected light from the sensor).

 

Sent from my LG-H815 using Tapatalk