Re: Grad ND, Contrast and Color FIlter Setup with Center Filter
If you regularly use ND grad filters then I think 4x6" ND grads are the way to go with LF. Re your problem child 90mm lens with CF: there is a press-on filter holder that can accommodate this, but it is expensive and is not a good solution for combining an ND grad with a circular polarizer:
https://www.robertwhite.co.uk/lee-fi...er-holder.html
With this setup I would position a square linear polarizer in front of the ND grad, which would not always provide optimal polarization since it could only be positioned in 90 degree increments, but often that would be adequate. I used this setup mostly with my 8x10 camera and did not experience any significant vignetting issues. I doubt you would see much vignetting with your 90mm lens with CF on 4x5 with just an ND grad, but suspect you might see some when you add the square polarizer on top.
Frankly it would be more practical to either accept the light falloff without the CF or purchase a smaller lens.
Re: Grad ND, Contrast and Color FIlter Setup with Center Filter
Quote:
Originally Posted by
Alan Klein
Why is 105mm "way too big"? What did you mean?
I don't want to carry around 105mm filters. They are way too big, heavy, and/or expensive. Most of the time I don't even use GND filters, I just wave the darkslide in front of the lens for half or 3/4 of the exposure to get 1 or 2 stops of "GND."
I'm still perplexed why you can't just do exactly what you do with MF on 4x5. It's literally no different, except you might have to check your coverage if you go overboard with filtration and movements on wide or ultrawide lenses.
Re: Grad ND, Contrast and Color FIlter Setup with Center Filter
Quote:
Originally Posted by
Drew Wiley
The inner thread diameter of the CF is 82mm, the outer much larger, almost a funnel effect, so that the lens/CF combination can be used with maximum movement when stopped down to the rated f/22 or so recommended with CF filters. I don't see how a Cokin ND grad is going to help even things out if the bigger elephant in the room is circular falloff itself, which the CF corrects. A Cokin ND grad would also introduce a bit more spacing and flare issue. Ideally, it would be used even further oversized outside the 90 lens/CF sandwich, which would still allow a circular contrast filter to be used in between if desired. If one opted for the smaller 90/8 Nikkor with a 67 CF instead of the 90/4.5 with an 82mm CF, then the cumulative density of all that intervening filtration can make considerably dimmer focus and composition a distinct chore, so in this respect the brighter 90/4.5 SW is a distinct luxury. Yes, the CF can be used optionally. But if movements are modest, and it's well stopped down, then the 77mm system might work. You would just have to look through the cut corners of the ground glass to see if there's any mechanical vignetting or not.
Your point seems to indicate the elephant in the room if you don't use the CF. Wouldn't the Cokin grad ND filter work similarly as on any other lens once you put the CF on the 90mm?
Regarding using the 77mm filter set, how would you do that with adapters?
Re: Grad ND, Contrast and Color FIlter Setup with Center Filter
Well yes, without the CF you have 1-1/2 stops of falloff center to edge. With it, you're back to even illumination. It would be best to attach 82mm circular contrast filters directly to the lens, then the CF into that. Your Cokin ND grad system has an optional 82mm adapter. You'd need one on each side if you're going to place that in-line too, but they're inexpensive.
Re: Grad ND, Contrast and Color FIlter Setup with Center Filter
Drew, you're making things much too complicated for him.
Alan, you really don't need a CF for your 90mm lens in most applications. All you are doing here is needlessly twisting yourself into knots over an almost non-existent problem. I have shot literally thousands of sheets of 4x5 with various 90mm lenses and have used a CF with maybe 2 or 3.
You can learn 100x more about what you need by just shooting a bit with your current gear and evaluating what you get on the film. And if you are worried about critical images, you need to test, test, and test again anyway before shooting those images.
Re: Grad ND, Contrast and Color FIlter Setup with Center Filter
Corran, I just noticed on a different forum he's fond of Velvia. Understanding center filter use in that case is rather important; it's an unforgiving film in terms of latitude, and losing a stop and a half in the corners will stand out like a sore thumb. For ordinary black and white film work, the CF could be considered optional.
Re: Grad ND, Contrast and Color FIlter Setup with Center Filter
Perhaps you can help me find the dire amounts of fall-off on this sheet of Velvia shot with a 90mm and generous front rise I shot long ago, before I knew what a CF even was:
http://1.bp.blogspot.com/-RyR6iDX0Qy...titled-57s.jpg
Re: Grad ND, Contrast and Color FIlter Setup with Center Filter
Well, right now my holders are loaded only with Tmax 100. Steven suggested I shoot two sheets with my 90mm (Nikkor f/4.5) with and without the CF on the same shot to see the difference and what I liked. I have heard though that color is more sensitive as Drew mentioned. But I'll try the same procedure of two shots once I start shooting my Velvia. Corran-nice picture.
I have a 75mm (Fujinon f5.6 SWD) on order but no CF. I suspect that's going to be more of an issue. All I have to say is medium format was a lot easier. All four lenses I had took the same sized 77mm filter and I didnt have to deal with LF issues like CF's. :)
Re: Grad ND, Contrast and Color FIlter Setup with Center Filter
If you can't see the falloff in that image, Corran, maybe you need a white cane instead of a tripod. I don't know how much you've tinkered with it in PS to post it, but I'd hate to try to salvage print that image. It's an attractive scene, but the wrong film choice if you don't like using center filters. Let's hope the new E100 survives the present financial upheaval; it would do a lot more justice to the hues in the scene,
but still would need a center filter to handle the full contrast range ideally.
Re: Grad ND, Contrast and Color FIlter Setup with Center Filter
I can't physically roll my eyes hard enough.