Vignetting on CV 15/4.5 with Milich filter holder

[Hacker]

Originally Posted by chris_tribble

difficult to see how to fix without redesign a there's such a small surface to fix to on the CV...
Best

If there is a redesign, may I suggest that the the edge of the hood have a thread to fit caps from Kirk? Kirk Protective Accessories and Tools

Just an idea.

[jscottyk]

I just encountered this problem too. Did a test and noticed the vignetting at all apertures but the situation improves at f11 and f22.

Sounds like this could be related to the installation of the filter. I'm using a Leica filter and when it's screwed in (the backside of the holder) as far as what seems possible I still have about 1mm of the filter exposed above the holder. Does that sounds correct? Or, should the filter screw in further and be flush?

[Woofer]

Same for me , in the extreme corners , Leica IR filter ... Jim perhaps you've not heard about this because , like me , others have just shrugged it off as user error , and cropped.

Regards

Leslie (PS not a complaint , I'm grateful for both the adapters for the CV/15)

[eric_bowles]

J. Scott,

Have you tried without the IR filter? I found I get vignetting with the adapter attached without the IR filter.

It would be great if the next version could eliminate the vignetting and also accomodate standard lens caps. I tried the Schneider 68mm but it's too small; I made some incisions but it doesn't quite fit.

--eric

[lars_bergquist]

The Cornerfix 'solution' is not really acceptable. The vignetting shouldn't have been there in the first place. Mr Milich should bring out a hood for a larger diameter filter. It is possible that even 41mm would do the trick. Maybe a change of thread would mean that we can't have Leica-branded filters. So what? The vignetting is more objectionable than any slight colour shift, which should be much easier to correct.

With my camera and lens, vignetting BTW occurs nearly exlusively in the top corners. This is something of a mystery to me.

The old man from the Age of Rube Goldberg

[gravastar]

Originally Posted by lars_bergquist

....................With my camera and lens, vignetting BTW occurs nearly exlusively in the top corners. This is something of a mystery to me.

The old man from the Age of Rube Goldberg

I may be able to offer an insight into this. Some time ago I experimented with several different screw in lens hoods for various M8 lenses. I was trying to find alternatives which would give maximum flare protection without vignetting. All was well until I purchased a backup M8. The second camera vignettes significantly in the top corners with some hoods. It would seem the sensor center is not aligned with the lens axis. I suspect it's this tolerance/misalignment which is causing the trouble with the Milich hood.

Bob.

[jlm]

I'm looking into it. the present design was arrived at by making several prototypes, enlarging the opening until vignetting just disappeared. It looks like I need more of a saftey margin. Regarding centering and axial alignment, the attachment to the lens is less than ideal, given that it can only fit around the existing petalled hood and be side clamped with a set screw.

I will probably increase the opening and set it to match a standard lens cap.

as far as choosing a larger filter, uh-uh, tolerances are too tight.

[jscottyk]

Have you tried without the IR filter? I found I get vignetting with the adapter attached without the IR filter.

No, I haven't tested without the IR filter. Will do that iteration soon.

With my camera and lens, vignetting BTW occurs nearly exlusively in the top corners.

Mine is vignetting evenly across all four corners.


Any comments from anyone regarding my installation of the filter question?

[sandymc]

Originally Posted by gravastar

I may be able to offer an insight into this. Some time ago I experimented with several different screw in lens hoods for various M8 lenses. I was trying to find alternatives which would give maximum flare protection without vignetting. All was well until I purchased a backup M8. The second camera vignettes significantly in the top corners with some hoods. It would seem the sensor center is not aligned with the lens axis. I suspect it's this tolerance/misalignment which is causing the trouble with the Milich hood.

Bob.

I can confirm that - taking a close look at CornerFix vignetting data shows very clearly that the various sources of vignetting are often centered in quite different places, the various sources of vignetting being being conventional optical vignetting, the vignetting from the sensor/microlenses, and mechanical vignetting from the lens/hood/filters. I've seen those centers each be as much as 10% off the optical center of the sensor.....

Sandy

[jlm]

what is the best way to test for vignetting?

my guess is: focus at infinity (shortest distance to film plane and probably most influence on vignetting), stop down to f8 or f11, shoot image of neutral wall or sky.

or: focus at near distance (attempt to sharpen vignetting elements in image), and same as above

??

[stunsworth]

John, I think you want the lens to be open rather than stopped down. I was out today using my 15mm and filter adaptor and the vignetting was very obvious at f5.6.

[sean_reid]

Hi John,

Evenly lit wall is best. Try closest focus distance, about 7 feet and infinity.

--------------------------------

Earlier versions of the CV 15 filter adapter I tested did not vignette but I, too, have a copy here that vignettes and John and I were discussing that last week. I'm sure he will sort it out.

Cheers,

Sean

[jscottyk]

For my test I shoot at infinity towards a clear blue sky with the sun at my back. One exposure for each dentent changing the shutter speed. 10 exposures in all. Vignetting occuring in each image.

[ronaldh]

Originally Posted by sean_reid

As I mentioned in my review, Schneider makes a 68 mm cap.

Cheers,

Sean

I found a plastic 68mm Leica push - on cap on Ebay. No idea what lens it's from

[nboeck]

I just bought that lens cap and it fits but is very loose - it would have to be taped down or strapped down to stay on, not sure if it is like that on yours o if the new Milich hood is now a bit smaller...
I bought the filter adaptor for the 12mm version, not sure if there would be a larger hood if I'd told him it was for the CV 15mm. I can't imagine there are two versions but wanted to add that bit of into....

Originally Posted by sean_reid

As I mentioned in my review, Schneider makes a 68 mm cap.

Cheers,

Sean

[photolandscape]

Originally Posted by nboeck

I just bought that lens cap and it fits but is very loose - it would have to be taped down or strapped down to stay on, not sure if it is like that on yours o if the new Milich hood is now a bit smaller...
I bought the filter adaptor for the 12mm version, not sure if there would be a larger hood if I'd told him it was for the CV 15mm. I can't imagine there are two versions but wanted to add that bit of into....

I have what may be the most humorous lens cap solution of all, and it works beautifully--it's a Vivitar (probably 68mm) push-on cap that fits perfectly. Snug, and won't fall off in my bag. I've gotten a few peculiar looks from people who see the juxtaposition of the M8 body with the Vivitar log on the cap.

[tvleeskr]

I received my Milich CV15 shade/filterholder today. It appears the vignetting is worse at 5.6 then when fully open. Will do some more tests tomorrow and post.

[lars_bergquist]

I presume a 41mm filter would fix the problem. Might Mr Milich perhaps consider making an adapter for 41mm, making it available to people who have got this vignetting? Also, as the future standard for 'adapterising' the CV 15mm lens.

The old man from he Age of the Angulon

[sean_reid]

Originally Posted by lars_bergquist

I presume a 41mm filter would fix the problem. Might Mr Milich perhaps consider making an adapter for 41mm, making it available to people who have got this vignetting? Also, as the future standard for 'adapterising' the CV 15mm lens.

The old man from he Age of the Angulon

Hi Lars,

Actually, he justs need to trim the hood back a bit.

Cheers,

Sean

[chris_tribble]

Check that you have Lens recognition on + that your lens has been coded + that you select the CORRECT lens length when the menu comes on. If you do that, no vignetting. If you don't - DARK corners.

I was caught out - it's annoying quirk of the M8.