Compendiums eliminate flare. And don't create focus shifts and don't degrade the image due to the condition of the filter.
Compendiums eliminate flare. And don't create focus shifts and don't degrade the image due to the condition of the filter.
I agree about compendiums and I agree with you about everything else in your lat est post Bob. Still I am curious as to whether or not there are other benefits. Are there?
Signed,
Perplexed in texas
What other benefits do you want?
Usin filters in front of the lens eliminates focus shifts and vastly reduces image degradation (except from grossly defective filter). Putting filters behind the lens creates focus shifts and does create image degardation from marred filters. In addition flare occurs on uncoated glass to air surfaces. if a non coated filter is behind a MC coated lens flare can occur
Oh yes,
They also protect the front element of the lens.
One instance I've found advantageous for putting filters behind the lens is when using multiple gels to correct artificial light color to match transparency film.
Multiple gels in front of the lens will cause ghost images of bright light sources (such as HID lights in a gymnasium). I use 3" gels for compactness, but they're too small to curve in front of the lens.
Rear lens elements are smaller than front ones, so the 3" gels fit there, with room for some curvature of the gels. The curvature removes the ghosts.
There are problems with this method, but it's the best way I've found to solve that particular ghosting problem.
Don Wong
Seems like a properly functioning compendium masked to only letting rays that wi ll reach the film would eliminate a ghosting problem.
A lens hood or an improperly extended or / and masked compendium would not.
This is why Linhof builds gel holders into their compendiums.
I just got a chance to inspect and handle the GLIDE 6x17 panoramic camera this past weekend, courtesy of Jeff Wheeler of QUALITY CAMERA in Atlanta. the camera was equipped with the 72mm XL lens with the center weighted filter (evidently it is definitely needed for the 6x17cm format. The mattebox/filter holder they were using was the new Cokin X filter holder with a self supporting shade made by Camera Bellows, ltd. (and sold by Lee). This holder is designed for 125mm (5") wide filters which are standard in the motion picture industry. There was no vignetting as far as I could tell. The holder grabbed on to the outer rim of the CWF without any adapter as I could tell. The mattebox (filterholder and compendium shade cost US$500.00.
About the GlIDE: it is a fascinating camera. Very smartly designed with many brilliant and innovative, and eccentric features and is truly a work of engineering art. I particularly liked the way Dr. Glide solved the problems of lens movements bi-directional shifts (horizontal and vertical), tilts and focusing, and lens interchangability without having to resort to a monorail or bed, and also shifts and multiformats (6x6, 6x7, 6x12, 6x17) on the body of the camera, and the viewfinder. The design is eccentrically brilliant and the manufacturing quality is superb, of the same level as an ARCA-SWISS F or M camera or that of a Sinar P. It is very extremely pricey at about US$10,000.
I used the Lee holder you reference on hundreds of photos until the markings of my 72XL started to wear off. (Not really a problem but an annoyance, since the Lee holder mounts with a tension ring around the outer lens barrel.) But since I wanted to quickly interchange my square filters from the 72XL to my other lenses, I had to have two Lee holders with me and move the filters back and forth. I also always felt the standard Lee system was a little plasticy and imprecise. I am reviving this thread to add that I have ditched the Lee holder and have been using the Benro FH100 -- 100mm filter holder for about two years and it fits the 72XL and all the other lenses with one aluminum filter frame, and separate threaded filter rings which I have permanently mounted on all my lenses. It fits the XL with a threaded 95mm low profile ring, that allows for a rotating polarizer to be attached behind the 100mm square filters if that's your jam. I have my holder set up with two filter slots. There are a number of new filter holders on the market competing with Lee now.
Schneider SA 72mm XL with Benro FH100 filter holder (you can see the markings worn off the lens from the Lee holder)
Benro 95mm filter ring
On another note, I use a Schneider Attenuator or Lee Blender graduated 100mm cinema filter to remove vignetting from lens fall off when I think it will be a problem. This way I avoid needing various expensive Center Filters on the lens and all the fiddly bits associated with them. With the large XL image circle on 4x5, I only use the filters when the lens is shifted over 15-20mm from center and into the light falloff area. This happens very often with front rise in HABS work. I find the centered sweet spot of the 72XL image circle to be pretty even in light coverage, just like the center of a Center Filter is pretty even in density until you get to the edges. This may not be exact enough for transparency shooters, but neither is the metering for a heavily-shifted exposure through the less-dense part of a CF. More art than science, I imagine.
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–Stephen Schafer HABS | HAER | HALS & Architectural Photography | Ventura, California | www.HABSPHOTO.com
I use 4" gels (poly) with mine. Either handheld or in a Lee snap holder. Unless you are using f/5.6, then your image rays don't go through all the glass and your filter doesn't have to cover everything perfectly.
my picture blog
ejwoodbury.blogspot.com
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–Stephen Schafer HABS | HAER | HALS & Architectural Photography | Ventura, California | www.HABSPHOTO.com
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