New to LF questions part Deux

[Bob Bell]

These are a second set of questions so bare with my second thread.

Lens Hoods: I use them on every lens that I own in the smaller formats, I notice in LF there isn't a lot of mention of them. I know hoods, in addition to providing some protection, often allow higher levels of contrast and control off axis flair. What are the common solutions here? Screw in B+W hoods for each lens size?

Filters: I have Heliopan K Circ Pol's. I know they are problematic in 35 and MF on very wide lenses due to curvature of the lens changing the angle to polarized light. Will I have that problem with a 90mm? I know how to fix it in photoshop, its just quite a bit of work. .

Vignetting: How tolerant are large format lenses to normal sized filter mounts in relation to vignetting? Such as a 77mm on a step up on a 67mm filter size lens. This also relates to the Lens Hood question.

What is the filter thread on the back of some lens for?

Thx again for your patience with my new LF user questions. Some of the threads I have found touch on things but its more conjecture than definitive statements.

[Gordon Moat]

I already owned several metal Nikon hoods with 52mm filter sizing. So on my 135mm f5.6, I added a step up ring to allow fitting the Nikon hoods (usually an HN-1 or HN-2). A compendium might be a better solution, or possibly that clip on Ebony item with the board. Unfortunately as I add longer lenses, the filter sizes, and hood sizes, get larger. I still like the compact sized round hoods, so I might standardize on 72mm sizes for my bigger lenses.

Other odd items I have are a Cokin P holder, with a few different adapter sizes depending upon threading. I also recently tried out one of their plastic fixed hoods. Another alternative is the Lee bellows in Cokin P size, which functions sort of like a compendium.

Ciao!

Gordon Moat
A G Studio

[John Kasaian]

I use a hat, but with wide angle lenses that can be problematic. An exhibitionist with a raincoat works well. Just position him in front of the sun or reflective surfaces before fine focusing to make sure he's not in the shot If you can't find an exhibitionist (a bail bondsman can usually supply a few references) you might be able to obtain a "rubenesque" mother-in-law as an alternative

[Ron Marshall]

Lens Hoods: Screw-in or clip-on or compendium (like a bellows)

Filters: The sky may vary in brighness when a polariser is used and this is the same in all formats, just depends on the lighting conditions.

Vignetting: It depends on the image circle of the particular lens. If the lens has lots of extra coverage a bit of filter vignetting ins't important.

What is the filter thread on the back of some lens for? On some lenses the front element may contact a filter, unless a special filter is used. That is the case with my SS XL 110.

[Brian Ellis]

A compendium shade is probably the best solution but they're kind of a pain to attach and use, at least the one I had for a Linhof Technika was a pain. I don't think those little round shades that screw onto the lens do a whole lot of good in large format (probably not in 35mm either). Lee makes a lens shade (actually several I think) that function much like a compendium. You buy an adapter for each filter size on your lenses (or buy only one for your largest size and use step down rings for the others). Then the shade screws into the adapter. I used that system too and it worked pretty well but I'm not up on all the wide angle and other versions, when I bought mine there was only one.

The threads on the back that you mention are for filters, some lenses will allow you to attach a filter on the rear rather than the front when the front glass protrudes too far to allow a front filter to be used.

I also used the Ebony clip-on item someone mentioned. It doesn't do anything that your hand can't do equally well in terms of shading. Its only advantage is that you can position it and then check the ground glass for vignetting, it's hard to do that with your hand since after checking with your hand in position you have to use your hands to put the film holder in the camera.

The advantage of a good shade is that it doesn't just stop direct light from striking the lens, you can do that with your hand. A good shade will prevent all extraneous light from striking the lens, including for example diffused light on a cloudy day that's coming from all directions.

[walter23]

Lens Hoods: I use them on every lens that I own in the smaller formats, I notice in LF there isn't a lot of mention of them. I know hoods, in addition to providing some protection, often allow higher levels of contrast and control off axis flair. What are the common solutions here? Screw in B+W hoods for each lens size?

I usually just shade the lens with a hand-held dark slide if I'm in a position where I'm worried about flare You'll always have a dark slide readily available if you're shooting in regular film holders.

Filters: I have Heliopan K Circ Pol's. I know they are problematic in 35 and MF on very wide lenses due to curvature of the lens changing the angle to polarized light. Will I have that problem with a 90mm? I know how to fix it in photoshop, its just quite a bit of work. .

That's nothing to do with lens curvature or anything weird like that. It has to do with the amount of polarized light in the sky. Maximum polarized light is at 90 degrees from the sun (in either direction) and minimal is directly towards and 180 degrees away from (with the sun at your back). There's a gradual transition across the sky, and with a wide or ultrawide lens you're going to see this when you use a polarizer. It's an intrinsic property of the sky, not anything to do with optics.

Vignetting: How tolerant are large format lenses to normal sized filter mounts in relation to vignetting? Such as a 77mm on a step up on a 67mm filter size lens. This also relates to the Lens Hood question.

You might lose some movements to vignetting, and you might see it in extreme wide angle cases. I've used the cokin P system (big bulky rectangular filter holder) on my lenses (even the 90) and I haven't had any problems with normal landscape movements (a bit of shift/rise to adjust composition and some forward tilt).

[Gene McCluney]

Almost 100% of LF photography is done with the camera on a tripod, with a cable release. In this situation it is quite easy to use your hand or a dark slide to shield the camera lens from direct sunlight, as you can stand beside the camera, rather than in back looking thru a viewfinder. Lens shades can cause vignetting when you use movements such as front rise, or tilt, which is very common technique in LF photography. You can't always see this vignetting with the lens wide open for focusing, but it shows up when you stop way down for taking the photo. The practice of developing LF b/w films to a more vigorous contrast than minature (35mm) negatives somewhat compensates for possible overall "flare" due to extraneous light outside the image area.

[BrianShaw]

... you might be able to obtain a "rubenesque" mother-in-law as an alternative

I have one that I'm not currently using. I'll give it to the first person willing to pay the shipping cost.

p.s. This "lens hood" will even cook for you if you are nice to her!

[Bob Bell]

Thats too funny. Why do I think you won't honor a 7 day return policy

[David Karp]

I have made something like the Ebony sun shield by using a clip for holding documents that is supposed to attach to a computer monitor. It has a long flexible tube between two clips. One clip attaches to the front standard, the other to a gray card that I take with me in my backpack.

I also use 67mm rubber lens hoods with my 52mm lenses. The hoods have a 52-67mm step up ring on them. Just check for vignetting. If I remember right, John Sexton used rubber lens hoods on his lenses when we went out one afternoon during a workshop. I may be mistaken. That does not mean that they work or that you should do it because he does it. It does mean that it certainly does not hurt.