Strange Soft Haze with Formatt Hitech Firecrest ND and Leica R 35mm

[Roddy Blelloch]

I had the weirdest soft- haze effect when I added a Formatt Hitech Firecrest ND 1.2 4x4 filter in front of my Leica R Summicron 35mm 2.0. I used the same filter in front of my Summilux 50mm 1.4 and this did not occur. Very strange. Any thoughts? Epic-W with standard OLPF on. I tried again with HiLight OLPF and had the same experience. Images below show a before and after image on the 35, and 50 with filter in place.

 

[Brandon Obey]

summicron and summilux might have a different coating and it may show when certain filters are used. just a thought

 

[Les Hillis]

Hard to say without knowing the character of the particular lenses you were using, or the exact shooting details. The 35mm pictures show you opened up the aperture when using the ND, which could have taken the lens from its narrower and sharper f/stops to its wider and softer ones. It also looks like you moved the camera closer to the subject in-between takes, possibly edging into the close focus limit and/or losing focus a bit around the narrower depth of field that resulted when the lens was opened up. The ND's extra layer of glass could have added a little something to the softening effect as well.

 

[Steve DiMaggio]

I have this issue all the time with anything over .6 with my firecrest and my leica r's, especially approaching wide open, my 90 is terrible

steve

 

[Stuart Graham]

Hi,
FIRCREST ND's are carbon coated & by default are IRND's too. This carbon process gives them the look of a PANCRO filter, Beam splitter or front silvered mirror.
Which way is your carbon (mirrored) side facing? maybe try it the opposite way (towards the subject)?

Like IRND's there's no right way or wrong way...just a thought that the 'diffusion' may come from internal reflections / bounce light / flare that the longer lens didn't see in the case?

In heavy backlight scenes I often have to spin mine (carbon side to lens) as sometimes there's a perfect square or rectangular reflection on the subject from a direct bounce from this carbon surface...obviously it depends on the angle of the source but somehow I just seem to find this angle

Cleaning process:
I was in Shanghai last week & my AC for 5 days (including our prep day) had only a piece of man made suede to clean all the glass with...DAMN! it was good! he never cleaned, replaced this faux suede or used any sprays etc.
My filters are normally a mess with diffusion oils but now as they sit in Tokyo for my next shoot, damn they're clean!...just sharing the knowledge.

Good luck getting to the bottom of this issue.

S

 

[paulcurtis]

Are all the samples shot at the same aperture, i assume not at the DOF in the 35 varies.

To me the cron just looks like the typical mandler glow when wide open. If you were to test again and use shutter speed to get an exposure just to test and see whether it looks like that without the ND.

This is very much a Leica R thing, i've been testing myself and a lot of the lenses have a very different character wide open to being stopped down, intentionally i think. It makes for a very useful stills lens but not necessarily for motion.

I could be wrong in this case, because i have to say the glow looks a bit over the top for f2

cheers
Paul