spitfire

<p>The biggest issues with filters:</p>

<ol>

<li>For filters that are not modifying the image with other than a flat surface (e.g. halo and many soft focus filters), it can introduce aberrations due to not having dead flat surfaces, or if its two surfaces are not perfectly parallel.</li>

<li>Flare from light reflecting off of the two air-glass interfaces that have just been introduced into the optical train. Light reflects from all boundaries between materials with different refractive indices, and that includes glass and air boundaries. It is the reason lenses have optical coatings which reduce the amount of reflected light. Flare is most pronounced when a specular or point light source is in front of the lens, casting light onto its surface even if it's not within the field of view.</li>

</ol>

<p>The best filters, such as B+W or Heliopan, have the flattest and most parallel high precision surfaces. While multi-coated filters cannot completely eliminate flare, they can reduce it. Ultimately flare control also requires light and composition control, including the use of lens hoods and other means to keep stray light out of the optical train. If the optical train is a low quality lens with aberrations, low contrast, poor flare control and low resolving power (i.e. poor MTF characteristics), filter quality and optical coatings won't make much difference. However, if the lens optics are world class, made by a firm such as Carl Zeiss or Schneider-Kreuznach, a poor quality filter can immediately plunge it into utterly mediocre optical performance.</p>

<p>A filter is another element and group added to the front of the lens. Its quality should be commensurate with the quality of the lens behind it. Keep that in mind when selecting and using one.</p>

Borrowed a 60 CT-4 a few months ago. I didn't have too much trouble sorting out its controls after about 10 minutes of playing with it on a camera with a "scratch" roll. Owning a pair of 40 MZ's helped greatly in sorting out the 60 CT-4 controls. The symbols are common among them even though the control layouts are considerably different.

One item still puzzles me though. There is a small switch under the head that can be seen only when the head is flipped up (pointing straight up). I could never sort out what it was for, simply left it where it was and everything worked OK. What is that switch for?

Thanks,

-- John

Although your question was posted some time ago I'll respond:

YES!! They are, indeed spectacular when properly mounted and projected using an excellent *lens* and screen (white matte is less reflective but shows finer detail).

Current MF projectors are intended for high end, professional slide shows; they're *not* consumer grade. Consequently they're also very expensive. Keep hunting for a decent used one. Although Robert Monaghan's MF projetor page is a little dated, it's still a good reference for what's out there (especially used) and their projection quality:

http://people.smu.edu/rmonagha/bronslideproj.html

For the individual who suggested scanning and then puting those up on a large screen TV, he obviously has never seen optically projected MF slides using a good projector *lens* and decent white matte screen. These blow away the resolution of a TV screen, hands down, no contest. Nor has he done the math for two things: cost and resolution required for 50-60 inch projection size. For the cost of the drum scans, yes *drum* scans, required to achieve the necessary resolution for a single roll of 120 shot using a 6x6 or 645, plus the computer necessary to handle the magnificently enormous file sizes, plus the magnificently enormous digital projection system to get even 40 inch horizonatl/vertical size, one could buy a pair of Rollei P66 duals, Schneider lenses for them, a dissolve system, and end up with an optical projection system that blows the TV screen away.

I use a Rollei P11 "Dual" although it's primarily designed for 6x6 slides in 7x7 mounts (also handles 35mm slides) and is *not* intended for dual format presentations (much better done with two projectors).

-- John

Yes, a shift lens can be used to make a "partial" panoramic. Make one shot full left shift and another full right shift. They should stitch together perfectly provided you tell the stitching software *not* to warp the images. I have done several of these using an Olympus OM SLR body and the Olympus Zuiko 35/2.8 Shift lens. As with cylindrical (rotated) panoramics, it is important to have the camera level when you do these, and *very* important to shift the lens carefully without nudging the tripod.

[Technically there is a very, very slight amount of parallax error in the shift, but it is so small (a typical 35mm shift lens is about an inch) that only an object extremely close to the lens whould show a parallax shift. To do it perfectly with absolutely zero parallax shift, you would have to shift the camera body and keep the lens in exactly the same position. This isn't practical though and most panoramics are scenic landscape, not close-ups.]

I have made a couple of small used equipment purchases from them. My

experience was good. They don't seem quite as organized as B&H but

have a huge selection of used equipment. If you're asking for

(ordering) something like a 45 year old instruction book or a 20 year

old camera case be patient as I think they sometimes have to find it

in their warehouse of stuff like that. Always been happy with the

condition advertised and condition received and the pricing seems

reasonable for the things I've looked for and found they had.

<p>

-- John