D700 vs df Viewfinder - Ease of focusing with manual focus lenses

<p>Hi there, <br>

A quick question for those who have got both. Given the fact that the Df was supposed to be used with legacy glass, is it's viewfinder better for manual focusing compared to the d700? <br>

Many thanks!<br>

Pat</p>

<p>First of all, there are many different opinions on this topic. I have no doubt that many would disagree with me. However, as far as I am concerned, a split-image focusing screen, perhaps with a ring of microprism, is a must for manual focusing with wider lenses. I don't find the Df's viewfinder any easier to use compared that on other Nikon DSLRs.</p>

<p>Of course, with digital, using live view is now a better way to manual focus. But your camera needs to be on a tripod.</p>

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<p>a split-image focusing screen, perhaps with a ring of microprism, is a must for manual focusing with wider lenses</p>

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<p>Funny, that was always the first thing I replaced in any of my film SLRs - but then the fastest glass I had to focus was f/2. The split-image and microprisms were pretty much useless on lenses with a maximum aperture of f/3.5 or slower.<br>

Inadequacies of the current AF focusing screens as well as "age-related" changes in my eyesight have made it pretty much impossible for me to reliably manually focus lenses on DSLR cameras - I very much prefer to do that in the EVF of a Sony A7.</p>

<p>Dieter, that was the first thing you replaced in your film SLRs because split-image center with a ring of microprism was pretty much the standard in the last manual-focus film SLRs in the 1980's, before auto focus took over.</p>

<p>My first SLR was a Minolta SRT-101 which had only microprism, which I found insufficient as I prefer image matching in rangefinders (such as the Leica M). At the time some Nikkormat only had split-image. By the mid 1970's, split-image + microprism was pretty much the standard for over a decade until the beginning of the AF era in the late 1980's.</p>

<p>Of course, just because something is the "standard" since it fits a lot of people doesn't necessarily mean it will also meet your individual needs.</p>

<p>I upgraded my D700 to a D800 before I got the Df. But, I did do a side-by-side manual focus test between the D800 and Df. Based on detailed review of 1:1 crops from both, I could not pick a winner.</p>

<p>Don't the AF sensors work for a manual focus lens - the ball between two arrows. That's far more accurate than any split image or microprism screen. Nothing measures up to the precision of the continuous live view of an A7 with peaking and/or magnification.</p>

<p>I using a Nikon D3s, a D4, and a Df. Never had a problem to focus and I us a mix of lenses from AI to AF-S. Every time some of my fellow photographer looking thru of the Df, saying, ohhh, how bright it is. I never paid attention to it, just focusing all of the time manually. All of my viewfinder optically adjusted to my eye-site. To add more, I like the images the most of the Df, technically. Most of my images shoot with the Df, lately.</p><div></div>

<p>I am a film SLR user and since the start I don't use the microprism or split image (that's kinda defeat the purpose of an SLR) but I have found the Df is significantly more difficult to manual focus on the ground glass alone as compared to the F3, FM and a bunch of others like Pentax KX, Minolta XD-11, Minolta SRT 101. </p>

<p>The first thing I did when I got my D700 was to replace the standard screen with a microprism screen from focusingscreen.com. All of my lenses are AI/AIS and I had little faith in the focus confirmation dot compared to my eyes, most especially in low light. The microprism focusing screen is spot on.</p>

<p>I'm with Dieter. I always switched to a flat screen to focus because the split image, though great when it worked was almost useless in low light.</p>

<p>While I've no problem with split prisms in general (I have a Pentax 645 with one), I really find them to be outdated compared with modern expectations. They are, of course, absolutely fine if you want to focus on the middle of the image - but I don't often want to focus there, either for composition (that's not where I want the focus plane) or lack of contrast at that point. Focus-and-recompose is a nice theory, but the rotation of the focal plane means you're limited when you want a shallow depth of field (unless you have Hasselblad's accelerometer-based refocus trick) and as pixel counts increase the definition of "in focus" and the size of the depth of field is becoming redefined. It'd be interesting if someone could implement a focus screen that allowed the split prism to be moved around the frame (but more than a small matter of engineering). Live view, especially with focus peaking, seems like a much better long-term solution.<br />

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I'm prepared to believe a Df's finder is slightly better for manual focus - it's designed to be, obviously, although it certainly didn't stand out at me when I've tried one. Of course, if you're prepared to use the focus confirmation light as a back-up, the D700's MultiCAM 3500 has quite an advantage in coverage.</p>

<p>Yes, I`m also another who replaced the original K screens with B ones; but some years ago my eyesight started to go down so I had to make the reverse... now I need the original split image/microprism ones, without them I`m unable assure focus under certain conditions.</p>

<p>To me, eye fine focusing on a D700 is almost a dream. With loads of light, maybe.</p>

<p>Patrick, yes, the Df's viewfinder is widely regarded to be easier to use for manual focus than the D700's. However, opinions vary on how easy this is to do exactly; I think individual eyesight and the lenses used affect the results. It is possible to purchase focusing screens modified to fit various DSLRs, e.g. the S screen is regarded better for large aperture lenses (available from focusingscreen.com).</p>

<p>There is some discussion on manual focusabilility and replacement focusing screens on<br>

http://nikongear.net/revival/index.php?topic=539.0</p>

 

<p>I have used most of the FX digital bodies, other than a Df. If I had to grab one and focus manually by eye quickly, the D3 I had would be my choice. The D600 I had seemed a little better for MF than the D800 I had at the same time. I did have a D700, but don't recall using it much with MF lenses.</p>

<p>I struggled with wide angle manual focus lenses on the D800. The D810 seems a little better for eye and indicator focusing, I think. Short teles seem easier than wides for manual focus with the standard FX screens. I used a 75-150E on the D600 some with good results.</p>

<p>It was and is easier to focus manually with the older film bodies, for sure.</p>

<p>Can we lay this "faster lenses are easier to focus with a split image" myth to rest please?<br>

As has been known for some time, the visual focusing system used in Nikon SLRs and DSLRs shows absolutely no difference in brightness, nor any other aspect such as depth-of-field, at apertures wider than f/2. So it doesn't matter if the lens is f/1.4, f/1.2 or f/0.95; you simply won't see any difference in the viewfinder image over an f/2 lens - and this includes the behavious of the split image/microprism.</p>

<p>OTOH there may be an advantage to the AF system and electronic rangefinder, because the AF sensor is in the bottom of the mirror box of the camera and bypasses the viewing system.</p>

R.J., What is restricting the viewfinder to f/2 brightness?

<p>As you stop down, your eye compensates for the change in brightness. Furthermore, your eye has a logarithmic response to light. You see very little change over one stop, but it makes a big difference in the results.</p>

<p>Faster lenses have less depth of field, hence more "pop" when focused. At the same time, focus is more critical, hence easier to miss the exact spot in practice. The law of diminishing returns applies. DOF is proportional to the diameter of the iris, whereas the amount of light transmitted is proportional to the area.</p>

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<p>As has been known for some time, the visual focusing system used in Nikon SLRs and DSLRs shows absolutely no difference in brightness, nor any other aspect such as depth-of-field, at apertures wider than f/2. So it doesn't matter if the lens is f/1.4, f/1.2 or f/0.95; you simply won't see any difference in the viewfinder image over an f/2 lens - and this includes the behavious of the split image/microprism.</p>

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<p>R.J., What is restricting the viewfinder to f/2 brightness?</p>

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<p>It is more than that. If you mount an f1.2 lens on your Nikon camera and leave it wide open @ f1.2, how can the Nikon optical viewfinder automatically increase the depth of field to what you would get at f2?</p>

It's not the viewfinder, that would not get brighter, R.J. The visual focusing system does what it cannot not do. More light is more light. Not a myth.<br><br>Depth of field is another matter. It depends on the screen. Is it an 'active' screen, with some sort of microlenses, or just a diffusing screen? Those old diffusing screens also show the depth of field nicely. And we do see the decrease, i.e. have more trouble focusing an image with very little depth. Screens that use optical tricks to direct light towards the viewfinder's pupil also change how the image, and more particularly the out of focus part, looks. I don't know that this would behave such that there is a limit to changes you can see at f/2.<br>I don't quite agree that fast lenses have more 'pop', Edward. There is not such a great contrast between in focus and just out of focus. The shallow depth of field makes focussing much harder than any 'pop' would compensate for.<br><br>Split image rangefinders are not really affected by f-stop, except that when the lens' exit pupil gets too small, or too far away, the rangefinder will no longer be illuminated. They work fine, and keep working fine with fast lenses.

<p>A fresnel screen, typically used to increase finder brightness in recent cameras, only captures light from a subset of the cone leaving the rear element. The amount of defocus that's visible from apertures larger than the amount captured by the fresnel would be invisible, which is why f/1.4 and f/2 look very similar on many cameras. Similarly, a split-image finder (like autofocus systems) relies on capturing images from either side of the rear of the lens; they don't "look" at the edges of a fast lens, so, while they won't work any worse than on a slower lens, they also won't have the wider separation that might have been possible (and helpful with a narrow depth of field) if the finder screen was optimised to the lens speed.<br />

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Slight disclaimer: I only have a moderate understanding of how this works. But <a href="http://dougkerr.net/Pumpkin/articles/Split_Prism.pdf">this</a> seems informative.</p>

A Fresnel is 'old hat', has been included in viewfinders since the 1940s. They do redirect the entire cone projected on the focussing screen, in zones, making the angle of incidence less acute, i.e. directing that light more towards the screen and the viewer's eye on the other side instead of away to sides. That produces a more evenly lit viewfinder.<br>A Fresnel lens however does not create the visible image we need. A matte screen (etched or ground glass) does that by diffusing the light projected onto it. Most of that light will not be going towards ourr eyes, i.e. the finder is rather dark (compared to, for instance, the parts of the split image rangefinder).<br><br>New screens use techniques akin to what makes cat's eyes (the road markers) and projection screens work, i.e. instead of diffusing the light falling onto it, scattering it in many directions, they use tiny beads or cones all over the screen that direct the light towards one point, the place where our eye is supposed to be. So less loss, more light towards our eye = a considerably brighter viewfinder.<br>Those optical active screens however also have an effect on how the image looks, and in particular the out of focus parts do not look the way they will when captured on film or by sensor.<br><br>The difference between f/1.4 and f/2 is real and present. That we do not notice much is because of what Edward said: having enough light our eyes adjust to create a more or less equally bright impression. We will have to look for the difference conciously, compare the two, and then we will see it. Without paying special attention, we will start to notice things only when it gets either too bright or too dark.<br><br>Split image rangefinders are wedges, that divert light from the out of focus image, producing a lateral shift of the parts of the image each wedge covers relative to each other. The two images coincide when the light projected onto them is convergent on the wedges. They do not care about aperture size much, except that when the cone of light gets too narrow they no longer are completely illuminated and typically one half darkens (depending also on from where you look through them at the lens' exit pupil, i.e. depending also on the position of your eye.)

<p>I was referring to "popping" or snapping in and out of focus, not "pop" in the artistic sense of contrast and color. Sorry to have confused the terms.</p>

<p>Focusing aids such as microprisms exaggerate this effect, and it is what we look for in a superimposed image rangefinder, such as on a Leica M. We look for the confused image to suddenly "gel" or snap into focus, rather than the presence or absence of a double image.</p>

<p>Finders with a prism, using total internal reflection, tend to be brighter than those using mirrors. The latter are commonly used to reduce the weight and cost of components.</p>

I understood it that way, Edward.<br>The general idea appears to be that when DoF is shallow, it is easier to see when an image is in focus and when it is not. The differences between in focus and not in focus however are still small, the process of getting focus on the exact point where you want it to be (whether manually or using AF) is a nervous one, and i would say there really is no such 'pop'. It's harder, not easier, to focus a shallow DoF image, using a fast lens because there is not much DoF to cover mistakes. And as hard as ever to get it precise when not wanting to rely on DoF to cover mistakes.<br>But YMMV, and all that.

<blockquote>The difference between f/1.4 and f/2 is real and present. That we do not notice much is because of what Edward said: having enough light our eyes adjust to create a more or less equally bright impression. We will have to look for the difference conciously, compare the two, and then we will see it. Without paying special attention, we will start to notice things only when it gets either too bright or too dark.

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<p>This was bugging me, so I did an experiment. Here's a capture from my RX100 on manual exposure settings taken through the finder of my D810, with an f/1.4 Sigma 35mm mounted on it. Wide open (the D810's meter is off). Sorry this and the following image are so blurry - my finder diopter is set to accommodate my weird eyes, and I didn't really register that this might be why the RX100 was struggling until it was inconvenient to reshoot; I don't believe the blurriness affects the comparison, and I didn't want to try to compensate by sharpening in case the image processing seemed to affect the results.</p><div></div>

<p>Now trying that again. The D810 is focussed in the same place (the back of the chair - I didn't change the focus point). All I did is hold down the DoF preview button, set to f/2. The camera satisfyingly went "chunk" as the aperture lever moved. And there's no difference. Not looking through the finder (where I can actually see things in focus), not comparing these manual exposures - the white thing on the wall is almost exactly the same exposure. There's no difference to how out-of-focus the background is. There absolutely <i>is</i> a visible difference as you start to go to f/2.8.<br />

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Sorry, but I'm standing by the accepted wisdom that a fresnel screen in a modern DSLR doesn't show you the difference between f/1.4 and f/2. A genuine ground glass obviously would. This doesn't mean you can't see the focus plane, of course - perfectly sharp is still perfectly sharp - it just means that the rate at which objects appear out of focus as they become more distant from the focal plane is not the same in the finder as they are in the final capture at wide apertures. And that's always the advice I've heard on these forums.</p><div></div>