Unidentifiable Lens flare issue

Wesley Wong · Dec 25, 2004

Shooting a super 16 feature on Arri SR2, Vision II 7217 and 7218 filters most often used - 85 C, 81 EF Nd 3,6,9 (mixture of tiffen and Sneiders.)

saw some lens flare issues on the 'dailies' at telecine process.

Used matte box, french flags , cutters... yet we found strange flares that are always on the left and right of frames...

Can't figure this out.

Is this a problem on the Zeiss lenses ? (working on dodgy rented equipment-which didn't show the flares on the camera and lenses tests in pre-production.)

Can anyone comment ??

Thanks in advance.

Kevin_Zanit · Dec 25, 2004

It doesn’t really sound like lens flare to me. If the "flare" is always in the same position, regardless of it being a different setup, it leads me to think possibly light leak.

Is it possible for you to post a picture? It sounds to me like light leak from somewhere in the camera/ mag.

It’s a little hard to diagnose without seeing it.

Kevin Zanit

Kevin_Zanit · Dec 25, 2004

It doesn’t really sound like lens flare to me. If the "flare" is always in the same position, regardless of it being a different setup, it leads me to think possibly light leak.

Is it possible for you to post a picture? It sounds to me like light leak from somewhere in the camera/ mag.

It’s a little hard to diagnose without seeing it.

Kevin Zanit

laurent.a · Dec 26, 2004

You should try to find out what was the common parameter for all the shots that present this phenomenom.

Is it all the way thru on a roll, only some takes ? By checking the reports, you can find out if it was always with the same magazine...

Also you should talk to your kodak dealer as they can examine the negs and tell you what they think. They are really great for this kind of diagnosis...

(but it sounds like light leak to me too... was these rolls loaded/unloaded in special circumstances ? (high light outside) did you check your changing bag...

I sometimes had problems with magazines that would let light leak inside (just because a screw was missing) . I found a good way to diagnostic this : get into a dark room, put a lighten maglite inside the mag, close it, and move the mag in different directions. If you ever see light coming out... that means it can come in ! And you see where thru !

Wesley Wong · Dec 26, 2004

thinks after going through the cam reports , that it can't be a light leak issue.

it only happens on some lenses and not others .

Could this be a sign of the lenses itself, losing some of its multi-coating and allow a "vignette" pattern of lens flare ? They are REALLY old looking equipment.

Thanks for all the replies so far

laurent.a · Dec 26, 2004

If the antiflare multicoating is really damaged, may be it could do something, I don't know, but may be it can be not the lens itself but what is linked to it, matte box... Did you shoot inside or outside, with 85 on the lens on these shots ? I mean, is this flare bluish ?

Kevin_Zanit · Dec 26, 2004

It could possibly be the coating on the lens (Panavision even has a few sets of lenses with the coating removed called Flare lenses), but I think it is unlikely that the flare would be in the same place.

It could be a problem with the matte box, as Laurent said, or it could even be a light leak with the lens mount, and just some sizes of lenses cover the leak.

Like I said, if you could post a frame, we could probably help more.

Kevin Zanit

Wesley Wong · Dec 27, 2004

Hmm. thanks. will try to figure this out and see if I can get a screen grab sometime soon.

FilmUnited · Dec 29, 2004

Can you more specifically describe the "flares"? Are there lenses that tested fine then preformed poorly during the filming?

I once sat in on a supervised color correction session for a film shot on an SR2, and one of the rolls had streaks of light on both the right and left side. It was discovered that the mag itself contained no light leaks, but that the AC had not engaged the mag all of the way, thus letting in slight leaks on both the left and right side. On the SR2, you insert the metal on the top part of the mag into the camera body, then snap the back end downward, and although it may seem engaged, if it doesn't click, it will leak on both the right and left sides.

Could this have been what happened?

Corey

Wesley Wong · Dec 29, 2004

hmmm...

I'm the AC (only 1) and I better check with my DP about thsi then.
We have issues with the 2 mags (ONLY 2 can you believe it !!!!) whereby one of it actually dropped out whilelocked and also came loose while we were loading a new roll and fogged the whole 400' .

We are not amused at their gear...