lf-photo.org.uk

Hello to all,

This is my first posting as a new member so a short introduction might be appreciated.

I am a Senior Citizen (73 years young) wth a renewed passion for LF photography using a recently acquired 5x4 MPP monorail and a Tachikara.

An artist friend has asked me to photograph his work which includes oil paintings many of which carry heavy layers of paint. When lit using two diffused tungsten Arrilite 800watt heads at 45 degrees to the subject, there are numerous specular reflections on the painting which I wish to either eliminate or significantly reduce.

I understand that this can be achieved by using polarizing filters on both the lights and the camera lens? Do any members have experience in this type of work? If so, then your comments would be much appreciated.

Peter

Petenk wrote:Hello to all,

This is my first posting as a new member so a short introduction might be appreciated.

I am a Senior Citizen (73 years young) wth a renewed passion for LF photography using a recently acquired 5x4 MPP monorail and a Tachikara.

An artist friend has asked me to photograph his work which includes oil paintings many of which carry heavy layers of paint. When lit using two diffused tungsten Arrilite 800watt heads at 45 degrees to the subject, there are numerous specular reflections on the painting which I wish to either eliminate or significantly reduce.

I understand that this can be achieved by using polarizing filters on both the lights and the camera lens? Do any members have experience in this type of work? If so, then your comments would be much appreciated.

Peter

As far as I know, it`s quite a specialist task and diffused lights balanced for daylight with polarising sheets might be required and also a polarising lens filter as well to minimise any relections. Also, the type of film used is important and should provide fairly neutral colours. Kodak EPN used to be popular with some commercial photographers, although I`m not sure if it is still available. Perhaps a colour negative film such as Kodak Portra 160NC or Fuji 160S could be used instead.
Hopefully, someone here will know more about this type of photography or try a Google search for "How to photograph oil-paintings?".

Thanks for responding Frank,

I have a 105 polarising filter for the lens and I found a Cambridge based supplier of a polarizing gel for the lights (it's dimensions would necessitate my buying quantity two) which at £68 each is a lot of dosh!

I will wait to see whether any other knowledgeable members have any other suggestions before I plunder my current account again!

Peter

Hello again Keith,

Please accept my apologiesfor my error in calling you Frank.

I will start taking the tablets again!!!

Peter

Petenk,
IME your best bet is to try using daylight if possible. This the cheapest & most effective lighting. Position the paintings on an easel, or piece of furniture where the lighting gives no reflections. Keep everything square to back of camera of course. Best wishes, Dennis.

Thanks for your advice Frank. I agree but..........

I have considered using daylight outdoors with the painting facing North. However, I have decided against this since we can't, in this country, rely on a contant level/colour temperature of illumination and/or indeed the weather! Photography indoors using difuse daylight poses similar restraints.

These are important factors since I have some 50 to 80 paintings to photograph and there is the need to standardise the ligting parameters.

I have taken the plunge and ordered two polarizing gels and I intend to give the artist the opportunity to choose between polarized and non polarized imagery. Hopefully, I will recover my expenditure one way or another.

Best wishes,

Peter

Dennis, I've done it again! Please forgive me for calling you Frank.

The tablets have clearly failed to have an effect!

Peter

Hello Frank, I mean: Peter,
I would be grateful if you could keep me/us posted on the results, since the situation you describe also appertains to the problem of photographing metallic objects (in my case mineral samples).
Thank you.
Charles

Good Day ..... Charles,

Thanks for your interest, I will keep you informed as to how things go.

I understand that using polarizers to reduce specular reflections from the shiny surface/s of metal is not possible. For what it's worth, in the far distant past when I faced similar problems (not geological specimens), I used one or more of the following techniques to eliminate unwanted reflections and to subdue specular reflections:-

a. Enclose the object in a white transluscent cube with only the front element of the lens in view to the object.

b. Spray the object with a very fine film of milk. Easier to remove than matt nail varnish.

c. Put the object into a refrigerator to get very cold. When removed, a fine film of condensation will be formed which will effectively subdue the reflection.

You may be aware of these techniques and some might not be suitable. Of the three, I preferred "a".

Peter

I don't know if anyone else has seen them, but Michael Reichmann's Luminous Landscape Video Journals are quite enjoyable, and pertinent to this thread is the interview with Bill Atkinson. Bill produced a book of photographs of exotic stones/crystals, and in one of the VideoJournals segments he describes his setup, which includes polarised lights and lens.

The particular issue in which this segment exists is LLVJ16, and costs $9.99 for download, a bargain I think for a most enjoyable watch.

I think this link should point to it :

http://www.luminous-landscape.com/zenca ... cts_id=138

Good luck

As far as I remember, Ian Biggar used to do a bit of painting photography in a "previous life" so it might be worth dropping him a PM but he hasn't posted much recently...

I'd heard of using polarised light sources and one on the lens for getting rid of reflections on metallic objects but I haven't had a go at actually doing it. There was something in one of the old Sinar books I have if I can find it amongst the general chaos of the bookshelf. I guess you use polarising gels across your light source (not too closely if using flash / redheads) or windows and then play with the combination of gel / filter rotation angles to get the required amount of cross-polarisation...

For those of you who might be interested, the 48 x 51cm polarizing gels produced by Rosco come with an info. sheet from which the following extracts are taken. Quote -

" To cross polarize, place the gels in front of the lights so that their axes are pointed in the same direction.....place the lights at a 45 degrees angle to the subject and rotate the lens polarizer until the glare diminishes or disappears.....in addition to glare reduction, the gels may be used for a vaiety of special effects including Birefringence (for crystal photography) and motion illusion

I quote the latter part of the above extract since it might pertain to the member who wishes to photograph geological specimens.

Peter

Petenk wrote:For those of you who might be interested, the 48 x 51cm polarizing gels produced by Rosco come with an info. sheet from which the following extracts are taken. Quote -

" To cross polarize, place the gels in front of the lights so that their axes are pointed in the same direction.....place the lights at a 45 degrees angle to the subject and rotate the lens polarizer until the glare diminishes or disappears.....in addition to glare reduction, the gels may be used for a vaiety of special effects including Birefringence (for crystal photography) and motion illusion

I quote the latter part of the above extract since it might pertain to the member who wishes to photograph geological specimens.

Peter

I've just stumbled onto this thread. I think you have just about got the problem licked: cross polarisation is the way to go. When I did this for a living I used Strobe strips either side of the artwork and when necessary applied gels to plane-polarise the light source, using the filter on the lens to cross-polarize the light.

From general experience polarising doesn't work so well on metallic objects.


Richard

Richard Kelham wrote:I've just stumbled onto this thread. I think you have just about got the problem licked: cross polarisation is the way to go. When I did this for a living I used Strobe strips either side of the artwork and when necessary applied gels to plane-polarise the light source, using the filter on the lens to cross-polarize the light.

From general experience polarising doesn't work so well on metallic objects.

Hi Richard,

I have "licked" this problem using cross polarised light etc. Now it's full steam ahead.

Thanks to all who contributed to this thread.

Peter