Rick Helmke Posted June 3, 2014 Share Posted June 3, 2014 <p>Morning all,</p><p>I just ordered the 150 soft focus lens for an RB67 from B&H. At the price it was just too good to leave. I've never even seen one of these so I know nothing about it. This one doesn't have the discs with it but I don't know what that means.<br>What are the discs and what is their purpose? I'm guessing it deals with just how soft the lens can be in a given situation. I'm hoping this lens has a separarate aperture. Anything anyone knows about it would be appreciated. It should turn up tomorrow and I'm looking forward to trying it out. Thanks.<br /><br />Rick H.</p> Link to comment Share on other sites More sharing options...
jim_momary Posted June 3, 2014 Share Posted June 3, 2014 <p>The lens ranges from F4 to F32.<br> Without the discs there is no soft focus, it 'becomes' a regular 150mm lens, per se.<br> The discs add softness when used with the aperture set to F4 or 5.6. If you stop down further, the effect is minimized and pretty much goes away.<br> The disks have a center hole and smaller surrounding holes which diffract light in a fairly controlled fashion and spread it across the frame a bit with more toward the edges. (It resembles one of those discs that goes in the old style meat grinder.)<br> Manual here. http://www.reznitsky.info/Mamiya/Doc/RB67_150mm_Soft_Focus.pdf</p> <p>Jim M.</p> <p> </p> Link to comment Share on other sites More sharing options...
c_watson1 Posted June 3, 2014 Share Posted June 3, 2014 <p>Oops...Any chance of a refund? The disc sets occasionally show up on eBay. I see SF lenses sold often with one or none of the discs. Had one briefly a few years ago and traded it off. I found the look got old fast, especially since digital blur can be better controlled.</p> Link to comment Share on other sites More sharing options...
joseph_dickerson Posted June 3, 2014 Share Posted June 3, 2014 <p>I think Jim is a little confused. The lens is soft without the disc(s) at f/4 and f/5.6, once you stop down to f/8, it is sharp. The disc(s) give you more control over the soft focus effect.<br> Like all soft focus lenses, focus stopped down to at least f/8.<br> I'm with C. Watson, I don't know how hard it will be to find a set of discs by themselves, but many of the lenses offered for sale seem to be missing them for some reason. <br> JD</p> Link to comment Share on other sites More sharing options...
q.g._de_bakker Posted June 3, 2014 Share Posted June 3, 2014 When reworded a tiny bit, Jim and Joseph are saying the same: the outer part of the lens is where the sof image is produced. Exclude it, and the softness disappears. The discs with holes are made that way to a) restrict the amount of light as if stopping down, and b) not to <i>"add"</i> but to retain softness by allowing light from the outer part of the lens to still reach the film.<br>You do need the discs. Or never stop down. Link to comment Share on other sites More sharing options...
Rick Helmke Posted June 3, 2014 Author Share Posted June 3, 2014 <p>I'll keep an eye out for them. You never know what may pop up. My favorite lens for the RB has always been the 180 but I saw the 150 for $49 and couldn't resist. I've decided to go back to doing more work on B&W film and the RB is my favorite tool for that. I'd like to do a line of B&W portraiture and want to do some more outdoor and landscape work producing larger silver based prints from my darkroom. I'm tempted to look around for a good 4x5 rig.</p> <p>Rick H.</p> Link to comment Share on other sites More sharing options...
jim_momary Posted June 3, 2014 Share Posted June 3, 2014 <p>I gotta lern how to rite betterer ... :o)<br> Jim M</p> Link to comment Share on other sites More sharing options...
c_watson1 Posted June 3, 2014 Share Posted June 3, 2014 <p>I really like the 150/3.5KL for portraits on the RB67 platform. Somewhat hard to find but improved optics and coatings over the venerable 180 and 180C.</p> Link to comment Share on other sites More sharing options...
joseph_dickerson Posted June 3, 2014 Share Posted June 3, 2014 <p>Rick...$49? Really? You should be ashamed of yourself!<br> Good on Jim for finding the manual. Everything you'll need is right there.<br> About a hunert years ago I did some lovely b&w flower stuff with the 150SF. Also used it to some effect for landscapes. It's not just for portraits anymore. <br> Just discovered my venerable 127mm doesn't sync with flash anymore. Might have to replace it with a 150SF, especially if I can find one for $49! Probably cheaper than repairing the 127.<br> JD</p> Link to comment Share on other sites More sharing options...
Rick Helmke Posted June 3, 2014 Author Share Posted June 3, 2014 <p>Well Jim I didn't want to say anything earlier but... :-)<br> Yeah Joseph KEH had it for $49. I couldn't believe it. They have 127's available for about that. It may be old gear but even so it seems dirt cheap.</p> <p>Rick H.</p> Link to comment Share on other sites More sharing options...
joseph_dickerson Posted June 4, 2014 Share Posted June 4, 2014 <p>I may need to look into that. I do dig my RB out of the closet for my students to use once in a while.<br> JD</p> Link to comment Share on other sites More sharing options...
rodeo_joe1 Posted June 4, 2014 Share Posted June 4, 2014 <p>How difficult can it be to get what are basically 3 lens caps and drill a few holes in 'em?<br /> Well, errr, actually quite a few holes, but it still ain't rocket surgery.</p> <p>Edit: Wouldn't a couple of suitably sized 0.3 and 0.15 ND filters do exactly the same job of cutting down light while allowing the periphery of the lens to be used?</p> <p>Edit to the edit: The filters would have to be gels of course, and you could cut an f/8 sized hole in the middle.</p> Link to comment Share on other sites More sharing options...
paul ron Posted June 4, 2014 Share Posted June 4, 2014 The soft focus is designed right in the glass, not a filter. The image is sharp but has a certain glow, mostly in the highlights n whites. It was a very popular playboy magazine lens back in the day. Ever notice how the girls seemed to glow? When the lens is used at full open aperture, you get max softness. Stoping down reduces the softness, and at f-8 there is no softness and can be used as a normal lens. Focusing is the issue with this lens. Stop down to f-8 n use the preview, (screen gets rather dark). The discs are used with the aperture full open, the equivelent f stop is on each disk for exposure calculations. This gives you the option of more dof without losing full softness. And again, stopping down will reduce the softness. So without the disks, you are limited to f-4 for full softness. Do some experimenting n have fun. The more you say, the less people listen. Link to comment Share on other sites More sharing options...
paul ron Posted June 4, 2014 Share Posted June 4, 2014 Btw, $49, buy buy buy! That is even worth it as a parts lens for me. The more you say, the less people listen. Link to comment Share on other sites More sharing options...
rodeo_joe1 Posted June 4, 2014 Share Posted June 4, 2014 <p>Paul. I see absolutely no difference between stopping the peripheral light rays partially using holes in a disc, or by reducing the intensity of the peripheral rays by using an annular ND filter. In both cases the DoF and degree of softness will be affected, as well as the exposure of course.</p> <p>What happens in either case is that the amount of peripheral (soft-focus) light is simply attenuated. Rather like mixing the opacity of a sharp and a defocused layer in Photoshop. In fact if the subject doesn't move, it would be perfectly possible to take wide-open and stopped-down shots and mix them digitally to achieve any desired degree of soft-focus. However, whatever method is used to attenuate the soft-focus effect, the DoF will be affected along with it. Therefore the primary purpose of the disc "filters" is to attenuate the degree of image softness, and not to control depth of field.</p> Link to comment Share on other sites More sharing options...
Rick Helmke Posted June 4, 2014 Author Share Posted June 4, 2014 <p>Joe I can't comment on how it works but the lens arrived today and definitely has a soft sort of glow to it. I'll try it out when B&H gets my B&W film delivered. It's worth noting that the discs fit inside the lens. Thanks to the above referenced manual I now know that the front section with some of the elements unscrews from the lens and the disc is installed. I can probably re-create the discs but I'd rather just get lucky and find some for sale. In any case I'm looking for shallow dof. I'll enjoy using it alongside the 180 and see just what the differences are.</p> <p>Rick H.</p> Link to comment Share on other sites More sharing options...
paul ron Posted June 4, 2014 Share Posted June 4, 2014 I've never tried nd filters on my sf 150... But i can tell for certain the discs preform as designed. Read the manual n see if your method agrees? The softness is built into the glass so when stopping down you over ride the edge aberations. The disc itself offers no softness at all. The disc just reduces the effective f stop while the holes allow the edge glass softness through.... But gives you increased dof as well. Is your nd method something you do.... Or an assumption? Oh wait... You're just controlling the amount of light from the edges with the nd? The nd has a hole in the center?... Similar to using a grad nd for sky control??? But it will offer no dof control. Interesting! The more you say, the less people listen. Link to comment Share on other sites More sharing options...
q.g._de_bakker Posted June 5, 2014 Share Posted June 5, 2014 Re DoF and ND filters: Everything that reduces the size of the beam of light projected onto the film will have an effect on DoF. Reducing that size by blocking the edge completely (which is what happens using an opaque stop, a regular diaphragm, a Waterhouse stop or these discs) will do it more radical than when you reduce the amount of light coming from the edge as using an annular ND filter would do, but that too will change the energy distribution in (i.e. the shape of) the CoC, and whether or not two CoCs are separated or not. The sieve diaphragms basically do the same.<br>So DoF will change.<br>That thing called Bokeh too. Link to comment Share on other sites More sharing options...
Rick Helmke Posted June 6, 2014 Author Share Posted June 6, 2014 <p>Well I ordered film and developer from B&H Tuesday and it got to Alabama today via UPS Ground. Not too shabby. I'll spend some time out with it this weekend and see what I get. Going to see how the 150 does as a landscape lens too. I guess now I'll have to go buy my buddies enlarger. As far as the soft effect goes, I've been using a filter with cheap hairspray on it as needed for many years with good effect. I think something like that softened up around the edges could be helpful. Won't cost anything to try. Graduated ND filters have their uses but I'm not going to want dark borders every time or even most of the time. I prefer not to have too much stuff hanging off the front of the lens if I can help it.</p> <p>Rick H.</p> Link to comment Share on other sites More sharing options...
paul ron Posted June 6, 2014 Share Posted June 6, 2014 You'll enjoy the glow. The more you say, the less people listen. Link to comment Share on other sites More sharing options...
rodeo_joe1 Posted June 8, 2014 Share Posted June 8, 2014 <p>Rick. My suggestion was to place the ND gels <em>inside </em> the lens where the original perforated filters are fitted. Not on the front of the lens.</p> Link to comment Share on other sites More sharing options...
Rick Helmke Posted June 9, 2014 Author Share Posted June 9, 2014 <p>Okay Joe I completely did not get that. That might work if I can find something fairly thin.</p> <p>Rick H.</p> Link to comment Share on other sites More sharing options...
wdgodwin Posted July 25, 2014 Share Posted July 25, 2014 <p>I love my SF 150mm. Used it for a couple of frames for bridal close up images during each session. No need to retouch. Studio strobes were metered for f8.0. When doing close ups at f4.0 I dropped a 2 stop ND filter in the bellows filter holder. For mid and full length poses shot at f8.0 with no ND filter. A little difficult to focus since you are viewing through the lens with aperture wide open. The magnifyer was a great aid for focus.<br> It's different from soft filters screwed in the front of the lens. The filter softens everything and all detail is softened, nothing is sharp. It was my understanding the SF lens is ground/polished for sharpness in center and not so much around the edges. When shooting at f4.0 (max softness), you actually use all the front element to get a slighly out of focus (outer element) image together with an in focus (center element) on the same frame that yields a soft image with detail. The only downside is you can't have both softness and DoF.<br> I have the discs set and shot a test series with each discs at each lens aperture when I first got the lens. After that, never used them. I just used f4.0 for the max, f5.6 for a little effect and then f8.0 and 11 for a sharp image.<br> Hope you enjoy yours.</p> Link to comment Share on other sites More sharing options...
arthur_gottschalk Posted December 3, 2022 Share Posted December 3, 2022 On 6/3/2014 at 5:03 AM, jim_momary said: <p>The lens ranges from F4 to F32.<br> Without the discs there is no soft focus, it 'becomes' a regular 150mm lens, per se.<br> The discs add softness when used with the aperture set to F4 or 5.6. If you stop down further, the effect is minimized and pretty much goes away.<br> The disks have a center hole and smaller surrounding holes which diffract light in a fairly controlled fashion and spread it across the frame a bit with more toward the edges. (It resembles one of those discs that goes in the old style meat grinder.)<br> Manual here. http://www.reznitsky.info/Mamiya/Doc/RB67_150mm_Soft_Focus.pdf</p> <p>Jim M.</p> <p> </p>Bot true. Without the disks, the lens is still soft until F8, when it becomes sharp/ Link to comment Share on other sites More sharing options...
arthur_gottschalk Posted December 3, 2022 Share Posted December 3, 2022 On 6/4/2014 at 11:29 AM, rodeo_joe1 said: <p>Paul. I see absolutely no difference between stopping the peripheral light rays partially using holes in a disc, or by reducing the intensity of the peripheral rays by using an annular ND filter. In both cases the DoF and degree of softness will be affected, as well as the exposure of course.</p> <p>What happens in either case is that the amount of peripheral (soft-focus) light is simply attenuated. Rather like mixing the opacity of a sharp and a defocused layer in Photoshop. In fact if the subject doesn't move, it would be perfectly possible to take wide-open and stopped-down shots and mix them digitally to achieve any desired degree of soft-focus. However, whatever method is used to attenuate the soft-focus effect, the DoF will be affected along with it. Therefore the primary purpose of the disc "filters" is to attenuate the degree of image softness, and not to control depth of field.</p> The lens itself has a built-in spherical aberration that creates the soft focus effect up to F8. Link to comment Share on other sites More sharing options...
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