Manual focus on a DSLR.

[Panama Hat & Camera]

In the good old times (certainly old times, but not so good) I focused manually my Olympus OM-2 (the same of my avatar) with a help of a focusing screen that had three mechanisms: a central circle with a split image (rangefinder spot), a microprism ring around the central circle and a matte field that covered the rest of the viewfinder.
I know that the autofocus of DSLRs are excellent, but sometimes, it is necessary to focus manually.
Do you know if there are any DSLR with split focus ring and other manual focus assist mechanisms?
Cheers,
Antonio.

[pnodrog]

http://www.focusingscreen.com/ I have only had a quick glance at it but you may find your answer there.

[William W]

Do you know if there are any DSLR with split focus ring and other manual focus assist mechanisms?

Yes.
None that I know of as an off the shelf purchase.
Some have (user) removable screens and you can re-fit other screens.
Some have (user) non-removable screens and you can have a technician replace the screen - you can have a go yourself.
'Katz Eye' is another company that you can research.

WW

[DanK]

yes, I still miss the microprism screen in my old Canon FTb. However, before you switch the focusing screen, there are a couple of things to consider. First, the throw (more precisely, the amount of rotation needed for a given change in focus) is very small on most modern lenses, compared to the old lenses designed for manual focusing. So, even a new screen won't entirely replicate what you were used to. Second, I have read that alternative focusing screens can degrade the performance of the AF system. I can't vouch for the latter myself, but perhaps someone else here can weigh in about this.

I find that I can get accurate MF with the regular screen, just not as quickly as with the old-fashioned screens.

[ajohnw]

People seem to be inclined to forget the light level problems with the old aids. My favourite was Fresnel microprism and 2 mattes. Something always worked. I can remember a split image one going dead black. Bit disconcerting in the middle of the view. The Fresnel screen just show a grid which isn't so bad. Ground glass - always works.

I understand Canon offer 2 screens for some of there cameras but hearing from some on who bought one he wasn't too pleased - it was for fast lenses only really. I believe that the standard ones are optimised for around F5. Actually on Canon I don't think the standard one is too bad. I've managed to focus short on purpose to deliberately reduce the depth of field.

The dioptre adjustment needs very precise setting with the eye relaxed at infinity focus - not easy to do and usually takes several attempts as the eye is more likely to be like that when out and about taking shots and not struggling to see if the setting is correct.

Now you mention it I suspect the D7000 just uses plain glass?

Just add - focus by wire lenses often have very good travel for manual use.

John
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[Manfred M]

There is another problem with manual focus, and that is that modern autofocus lenses have very short distance from near focus to infinity (and don't have a hard stop at infinity). This is there so that the camera can focus quickly, but makes it much more difficult to do an accurate manual focus.

My old lenses required one to turn close to 300°, whereas the modern ones are closer to 90°.

[ajohnw]

There is another problem with manual focus, and that is that modern autofocus lenses have very short distance from near focus to infinity (and don't have a hard stop at infinity). This is there so that the camera can focus quickly, but makes it much more difficult to do an accurate manual focus.

My old lenses required one to turn close to 300°, whereas the modern ones are closer to 90°.

I just checked my son's 100D and saw what I expected to see via the view finder, a slightly dim image because of the focusing screen and more than adequate rotation for manual focusing via the focus by wire mechanism.

I've also used focus by wire on m 4/3 using a magnified view so that I could see what was actually on the sensor. This is test target type work though and even these are a bit touchy but still usable for that.. For practical applications where things have depth I don't think this would matter. It's not possible to find the correct focus point on some AF lenses that have conventional focus rings. They may be ok in real situations but will be more tricky to use.

John
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[Manfred M]

Shooting at a small aperture and a wide angle is no problem John. My 8mm fisheye has most things in focus, even when I shoot wide open.

On the other hand, I tend to shoot mid-range telephoto lenses (f/2.8 70-200mm) wide open; and that's when manual focus is more difficult with modern glass on a modern body.

[ajohnw]

I've only looked at longer focal length lenses Manfred. One good thing from my point of view is that it seems the D7000 does have a focusing screen and if not suitable there is this one. Having just played with the standard one I suspect it's better than the Canon ones I have used. I'm a bit relieved about that as I will use it from time to time. That's why I have "upgraded" my DSLR then along comes focus peaking - not sure how useful that is yet.

http://www.ebay.com/itm/Double-45-Sp...-/350500221387

But I suspect people would soon find out about the light level problems with both the split image and the fresnel.

Maybe many have serious errors because of the problem of setting up the dioptre adjustment on the view finder. Our eyes can apply a serious amount of refocus in optical systems like these. The best example I have ever heard of was on microscopes. Some people who encourage youngsters to use them. As the specimens were a short distance away they looked through them with their eyes focused at that distance rather than relaxed as they need to be. They found that the kids were usually focusing their eyes to a distance between 6 to 9in. At least 30ft is needed to get decent views. I've managed to correct double vision due to a binocular head miss alignment. It made my eyes feel a bit strange and adjustment difficult. The harder I tried to look for errors the more correction my eyes applied. That aspect applies to setting up dioptre adjustments too.

John
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[Manfred M]

I' then along comes focus peaking - not sure how useful that is yet.

Focus peaking is great; they've been putting that into higher end video cameras for some years now. For HD video work, one can use a field monitor to focus, but peaking is almost as good and I use it all the time on my camera. The advantage over purely manual focusing is that peaking shows you what parts of the scene are in sharp focus.

[benm]

I use some old AIS lenses on my D800e. These are manual focus but fully compatible with the camera. On FF manual focus is not hard, though not as easy as it was with the split view/microprism. The viewfinder has helpful green arrows to indicate which way to turn the focus collar and lets you know when you have achieved best focus. And it is actually accurate.

[John Morton]

A good work-around that I have heard being recommended is to use "Live View" with magnification; 10X, for instance: but you would generally want to be using a tripod for the best results doing that.

When doing fine macro work with my old Olympus bellows mount macro lenses (I use to shoot with an OM-4 T before going fully digital and switching to a Nikon D700), I use Nikon Camera Control Pro 2 and shoot tethered to my laptop. This gives me the ability to adjust things using the computer rather than the camera, and to check how the focus actually is in my image.

I mostly use an Olympus Auto Bellows, so I can stop down the aperture after focusing the lens without touching the lens itself; but with the jury-rigged Olympus-to-Nikon adapter that I use, it is impossible to get an accurate sense of the image magnification without including a measurement scale in the image.

I can, however, easily take a shot at a wide-open aperture and then at a stopped-down aperture and can see on screen how the focus and depth of field are going to work out.

[inkista]

I don't think you're going to find a dSLR with a split circle/prism collar in the focus screen. But the closest you could come to it (if you shoot Canon) would probably be loading Magic Lantern and using liveview. That way, you'd have focus peaking, and "Magic Zoom", which is a zoomed inset (so you can judge framing, unlike with typical 10x zooming), which also allows you the option of "split screen", which will act like the split circle of an old-style focus screen.



If you have to have this type of aid in the viewfinder, then it may be time to ignore dSLRs, and look at Fuji X.

[Panama Hat & Camera]

http://www.focusingscreen.com/ I have only had a quick glance at it but you may find your answer there.

L.Paul,
Thank you for your answer,
Cheers,
Antonio.

[Panama Hat & Camera]

Yes.
None that I know of as an off the shelf purchase.
Some have (user) removable screens and you can re-fit other screens.
Some have (user) non-removable screens and you can have a technician replace the screen - you can have a go yourself.
'Katz Eye' is another company that you can research.

WW

Bill,
Thank you for your answer,
Cheers,
Antonio.

[Panama Hat & Camera]

yes, I still miss the microprism screen in my old Canon FTb. However, before you switch the focusing screen, there are a couple of things to consider. First, the throw (more precisely, the amount of rotation needed for a given change in focus) is very small on most modern lenses, compared to the old lenses designed for manual focusing. So, even a new screen won't entirely replicate what you were used to. Second, I have read that alternative focusing screens can degrade the performance of the AF system. I can't vouch for the latter myself, but perhaps someone else here can weigh in about this.

I find that I can get accurate MF with the regular screen, just not as quickly as with the old-fashioned screens.

Dan,
Thank you for your advice. I will verify if a focusing screen can degrade the performance of the AF system.
Cheers,
Antonio.

[Panama Hat & Camera]

There is another problem with manual focus, and that is that modern autofocus lenses have very short distance from near focus to infinity (and don't have a hard stop at infinity). This is there so that the camera can focus quickly, but makes it much more difficult to do an accurate manual focus.

My old lenses required one to turn close to 300°, whereas the modern ones are closer to 90°.

Manfred,
I think you are right about the very short distance from near focus to infinity of modern autofocus lens. My old 50mm f/1.4 Zuiko lens required about 180° to rotate from 0.45 m to infinity and it had two hard stops: one in each side.
Another problem is viewfinder size. In my old OM-2 SLR, it was 1X for 50mm lens.
With modern DSLR the viewfinder size is about 0.71X for FF cameras with 50mm lens and 0.5~0.6X for APS-C cameras with 50mm FFE lens.
Cheers,
Antonio.

[Panama Hat & Camera]

I've only looked at longer focal length lenses Manfred. One good thing from my point of view is that it seems the D7000 does have a focusing screen and if not suitable there is this one. Having just played with the standard one I suspect it's better than the Canon ones I have used. I'm a bit relieved about that as I will use it from time to time. That's why I have "upgraded" my DSLR then along comes focus peaking - not sure how useful that is yet.

John,
Thank you for your explanation. What is focus peaking?
Cheers,
Antonio.

[inkista]

...What is focus peaking?...

This is focus peaking:

[Manfred M]

Nice demo Kathy - on my Panasonic video camera, focus peaking shows the area that is in focus in bright red; the Sony example video is much more subtle than what I am used to.