Symmar 210 mm f1:5.6/370 mm f1:12

[miss.annette_leigh_haynes]

<h1 id="yui_3_17_2_4_1436765302003_760" >Large Format Symmar 210 mm f1:5.6/370 mm f1:12 if I take off Back Element which scale should I use f1:5.6 or f1:12 I do not have enough Bellows for 370mm?</h1>

[jose_angel]

<p>When you remove any group or cell to have a 370mm lens, you should use the f1:12 scale. It is actually a 370 f12 lens.<br /> The problem with this (convertible) lenses is that despite of the "real" focal length, with a removed cell the bellows extension needed is slightly longer than usual, so a 210/370 in the 370mm configuration will need near 450mm of bellows extension to reach infinity focus. Notice that the extension needed will be substantially longer to focus at closer distances.<br /> Depending on the camera you were using (some bellows are longer than others), it will be utilizable or not. Not so many field, press and compact cameras are that long, most are forced to use telephoto designs for such focal lengths. Anyway, just full extend your bellows and measure it.</p>

[miss.annette_leigh_haynes]

<p>This Is a 4x5 CC-400 Calumet with Bellow 16" Draw 20" Total I Paid someone to make me an Extended Lens-Board !-13/16 using 370mm still unable to Focus to Infinity<br>

(---Still missing my main question---) with Back Element Removed which Scale do I use Green f1:12 or White F1:5.6</p>

[jose_angel]

<p><em>>> When you remove any group or cell to have a 370mm lens, you should use the f1:12 scale.</em><br /> That is, the green one.<br /> Notice that Schneider recommend to remove the <strong>front</strong> element. If you remove the back one, it may happen that the scale is not as precise as expected, and the focal length could not be 370mm, but probably longer (or maybe shorter, I don`t know).</p>

[chauncey_walden]

<p>Schneider says: With the lens put together, it operates in the short focal length mode. By removing the entire front element (everything in front of the shutter), the lens is converted into the long focal length mode. In this configuration, use the green scales on the shutter to determine f/stop. Removing half the lens from the system affects the lens's ability to correct for aberrations. The long focal length mode is perfect for portraits, as the edges of the image will exhibit softness. In the short focal length mode (both lens elements in place), the lens will behave like a non-convertible lens in terms of quality and specifications.<br>

Now, 370mm is about 14 1/2 inches and if you have 16 inches of bellows then it seems to me that as long as the center of the length of the rear element is less than 1 1/2 inches from the back of the lens board you should be able to get infinity focus by running the bellows out until you get the center of the length of the rear element 14 1/2 inches from the film plane. If it is longer than 1 1/2 inches then you need to use the extension lens board and shorten the bellows extension until you get the center of the length of the rear element 14 1/2 inches from the film plane. In either event, you probably won't be able to focus much closer than infinity.</p>

[miss.annette_leigh_haynes]

<p>Chauncey Walden: You are correct The owners Manual is not correct it say Bellow Draw 16" 20" Total the Monorail only allows 14" so I will need to get a 20" Monorail to use the 370mm f1:12 I need 14 1/2 inches from the film plane and with this 14" Monorail I am 1/2" short<br>

I wis to thank everyone for your help on this Issue it is now Resolved.</p>

[jose_angel]

<p>If I recall it correctly, the 210/370 convertible Symmar actually needs more than 370mm (14-1/2") of bellows extension to reach infinity focus with the front cell removed. I think it was around 450mm (almost 18"). Don`t know if there are different versions.</p>

<p>So with 14" of bellows, you are not 1/2" short... you are about 4" short for infinity focus, and probably 6" or more short for a portrait distance.</p>

[david_l3]

<p>Those lenses are wonderful at 210mm and great pictures can be made with them. But in converted form they are difficult to use. I had a 210mm Rodenstock Sironar convertible lens, much like the Schneider 210mm Symmar. With the front element removed for the longer focal length it was very difficult to focus. The ground glass was dim and the exact focus point was very hard to find over a fair distance turning the focus knob back and forth. In theory it's useable but in practice don't count on it. </p>

[Dustin McAmera]

<p>It's true that focusing at f/12 is bound to be tricky (maybe you make your sitter hold a lit sparkler while you focus?)<br>

I'd still like to get that lens. </p>

[rodeo_joe1]

<p>Surely it would be cheaper - and give better image quality - to buy a proper telephoto lens of 12" or 14" focal length? Rather than modifying the camera and/or buying a new or extended bellows. The aperture would be a lot brighter than f/12 as well.</p>

<p>There are a couple of minty looking 360mm Tele-Xenars on *Bay at the moment. A bit pricey, but more affordable and scruffy ones come along fairly regularly. The bellows draw at infinity is only 220mm or so.</p>

<blockquote>

<p>"I'd still like to get that lens"</p>

</blockquote>

<p>Why Pete? It really is nothing special. Just a bog-standard Plasmat, and when converted a less-than-good dim meniscus.</p>

[jnanian]

<p>you need a ton of bellows for this lens converted to 370. <br>

as jose said about 480mm ( just for infinity ! ) it can be done with a smaller bellows camera. you can purchase what some have referred to as a top hat lens board ... it extends out ( think opposite of a recessed lens board ) and they look kind of like a stovepipe hat or an omega lens cone.<br />good luck !</p>