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View Full Version : ND filters for all panoramic cameras?



JJB
10-07-2010, 09:42 AM
I have seen where one kind of pano camera needed a center weighted nd filter. Do they all?

Thanks!

Ian Grant
10-07-2010, 09:56 AM
It's the lens that needs the filter not the camera, so no they don't all need a centre filter, only those using certain wide angle lenses.

For example a 6x17 camear with a 90mm or longer doesn't need a centre filter, a shorter lens like a 75mm needs one particularly for colour work, however with B&W you can get away with out one. I usually have to work hand held (no tripods permitted) so can't afford the speed loss of a centre filter on my 75mm and as I only shoot B&W I can dodge the edges of the negatives at the printing stage.

Ian

JJB
10-07-2010, 11:49 AM
Thanks for the info Ian. I am doing a bit of reseach with the intention to build my own. Yes, I am crazy...

A 6x17 uses a large format lens, correct?

Thanks!

Ian Grant
10-07-2010, 11:59 AM
Yes a 6x17 need lenses that cover 5x4 with room for movements. So while a 65mm f8 Super Angulon just covers 5x4 it's not quite enough for 6x17, likewise a 90mm f6.8 Angulon won't cover 6x17. Some wider more exotic XL Schneider's will cover but are rather expensive.

Ian

JJB
10-07-2010, 04:20 PM
Well, a lens for a 4x5 should cover a 6x12 without trouble. I can either go in this direction or look to optics for an 8x10.

Ian Grant
10-07-2010, 04:48 PM
Nearly all decent 5x4 lenses will cover 6x17 easily, it's a much more interesting format than 6x12 :D

It's only the very wide lenses like a 65mm SA that don't cover 6x17, many users go no shorter than a 90mm which will have loads of coverage.

Ian

Steve Smith
10-07-2010, 04:50 PM
Thanks for the info Ian. I am doing a bit of reseach with the intention to build my own. Yes, I am crazy...

Nothing crazy there - see my 6x12 link below..... Actually, yes, it is a bit crazy.


Nearly all decent 5x4 lenses will cover 6x17 easily, it's a much more interesting format than 6x12

Now he tells me!


It's only the very wide lenses like a 65mm SA that don't cover 6x17

That's o.k. then.


Steve.

pollux
11-10-2010, 07:31 PM
If you mounted a polariser onto a fuji g617 on top of the centre filter, would you need to stop down another stop, for example @ f11 losing one or two stops, to f16 or even f22?

LJH
11-11-2010, 07:09 AM
If you mounted a polariser onto a fuji g617 on top of the centre filter, would you need to stop down another stop, for example @ f11 losing one or two stops, to f16 or even f22?

1 - 1.5 stops for the CF; 2-2.5 for the Polariser. Total = 4 - 4.5 stops. 100 asa ends up somewhere around 5 asa.

So you'll also need to get your head around reciprocity failure as well. I shoot Velvia/Provia in colour and Acros in B&W to minimise reciprocity failure. Shot some film today with a Pol and CF in rainforest. Exposures were around 2-4 minutes...

pryan9
11-11-2010, 09:52 AM
I use ND filters for my pinhole. I converted a 6x9 zeiss folder and removed the bellows and the arms and then used a piece of sheet metal to cover the front of the camera. The field of view is now very wide because of the short focal distance from the pinhole to the film. Because of this, even with low ISO films my exposure time was relatively fast so to slow it down a little I started using ND filters.