When should one switch from manual to autofocus?

Discussion in 'Medium Format' started by graham_martin|2, Dec 30, 2009.

  1. This is not a uniquely Hasselblad question because it could apply to anyone who current has a manual focus medium format and is contemplating changing to AF. I have spent the last 6 months or so accumulating what, for me, is a nice amount of Hasselblad MF gear starting with a 500 c/m body, 50mm, 80mm, 150mm, 250mm and 500mm lenses. I currently use a WLF finder which has that wonderful magnifyer and a PME prism.
    I love everything about this system except the manual focusing. I just turned age 64 and I wear glasses. Even with the WLF and an acu-matte split screen I still have difficulty in focusing unless my subject is virtually stationary. Case in point. I spent the last two afternoons at our local rookery here in St. Augustine, Florida. Most of the birds are of the wading variety who tend to stay in one spot for several minutes at a time. However, they are constantly preening, moving their heads around, hopping to the next branch etc. which played havoc with my ability to get good focus.
    So, I am starting to think that perhaps I need to sell all this wonderful gear and an autofocus MF camera. I am curious as to the experiences of other users of manual focus gear and what prompted them to switch to AF. Other than cost, are there any down sides to going to AF? I did read in one of these threads that with a lot of the AF cameras the maximum flash sync speed is 1/125 compared to 1/500 on my Hassie lenses.
    If I were to make the switch I would be interested in an AF camera that has autofocus confirmation so that perhaps I could still keep my Hassie lenses and buy an adapter if I get a body other than a 'blad. Which does raise the question: Do any of the Hasselblad autofocus cameras, such as the the HI have an AF confirmation light in the viewfinder?
     
  2. I assume you understand zone focusing and dof.
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    The hassy lenses have reliable dof markings.
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    In your case, if the birds aren't flying, then focus on the near branch, note the distance. Repeat for the far branch.
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    Zone focus between these two distances. Works best if you have fast film.
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    AF doesn't work very well for Hassys for fast subjects. Even in a studio setting, it can take 1-2s for me to get the model's eyes in focus. I can do it faster on manual, and I don't worry abt battery life.
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    Look, you don't have to get the image perfectly aligned in the microprism for the shot. Dof does wonders if you know how to use it.
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    Perfect focus is necessary only if you're doing macro, or if your doing wide open close up portraits. At any reasonable distance to shoot birds without scaring them away, perfect focus is not a concern. The difference between 5m and 5.1m is negligible, and the difference between 5m and 7m can be covered by dof if you zone focus.
     
  3. That is quite an impressive list of Blad gear you have. Wai-Leong is indeed correct. Precise focus is not absolutely necessary if you use zone focus or focus on something of equivalent distance which works with your split image, a branch for instance, or the bird's beak, etc.
    I would also opt for the prism over the WLF. When I first got mine many years ago, it took me about 2 weeks to realize I hated the WLF and got an NC-2. It is still in my bag but only as a backup should something catastrophic, like a meteor coming down and smashing my NC-2 or something. :)
     
  4. Just on Wai Leong's post: if you're using the 250mm lens at f5.6 and focusing on something 5m away, the DoF (with a Circle of confusion of 0.045mm) is about 0.1m.
     
  5. I would agree with the previous posters that practice and technique can get you a long way. For example, focus at something the same distance as the bird rather than the bird, and it will be easier. Adding a little depth of field via stopping down a little can give you a little buffer. You might also want to look at a prism finder, which magnify a bit.
    If practice doesn't get you there, you will most likely have to look at a 645 systems, since the only two 6x6 systems which have AF/focus assist (to my knowledge) are expensive, as are the lenses (Rolleiflex 6008 AF, Hy6). The Hasselblad H is a much newer camera and the lenses cost a fortune, even second-hand, since they can still be used on the current models. There are much more affordable ways to AF/focus assist, such as a Contax 645, which has Zeiss lenses, like the V cameras. The Mamiya 645 options probably have too much shutter delay for wildlife, except the AFDIII and DF, both of which are also expensive.
    I own a Contax 645 AF, and it is a really nice camera. It has autofocus, as the name hints, and the lenses are great. Autofocus isn't fast, not like 35mm DSLRs, but it should be workable for relatively calm birds at medium distances. It is accurate, however, especially in daylight. Most of the lenses in the system are very good, and few cost more than about $1000 if you are patient. The 350mm is an exception, and is both hard to find and expensive.
     
  6. Thanks Wai-Leong
    Your brief refresher of zone focusing is helpful. While I fully understand DOF ( I was shooting at f/8 for that very reason), I hadn't been using the "near branch, far branch" technique. However I haven't been using the dof markings as much as I should have. I haven't taken the film to the lab yet, and so I may surprise myself if it turns out that I have more in-focus than oof shots. I did the same exercise with a manual focus lens on my DSLR, and I was about 50/50 on the in-focus versus oof shots. Then I used the live view focus aide on my D300 which was very helpful. That method allows me to view the subject on the 2 1/2" x 2 1/4" LCD screen and then "zoom in" electronically. Once I started doing that just about all the pictures were properly focused.
     
  7. I would also opt for the prism over the WLF. When I first got mine many years ago, it took me about 2 weeks to realize I hated the WLF and got an NC-2. It is still in my bag but only as a backup should something catastrophic, like a meteor coming down and smashing my NC-2 or something. :)
    I was using the eye level HC-4 which has a 3x magnification, plus a diopter that goes from minus 5 to plus 5. Would that be about the same as using an NC-2? It could be that I don't have the diopter adjusted properly, and that would be a contributing factor to my focusing problems.
     
  8. Just on Wai Leong's post: if you're using the 250mm lens at f5.6 and focusing on something 5m away, the DoF (with a Circle of confusion of 0.045mm) is about 0.1m.​
    I was using a 500mm lens @ f/8 which has an even narrow margin of error.
     
  9. Focusing medium format cameras, with their reduced depth of field (compared to 35mm). Has always been a challenge for most of us even when our eyes were young. Especially in daylight with a WLF. In my opinion, WLF's are made for studio use where the subject is the brightest thing in the room.
    A good split image focus screen has gotten me through many a dimly lit wedding.
    Towards the end of MF film's dominance of wedding photography. Most of the MF camera makers built 645 AF systems. These all worked good enough in bright light. But in dark wedding halls they sometimes caused focusing drama, especially if you were hurried.
    The Pentax 645N cameras are the lightest AF 645 cameras. The Mamiya, Contax, and Hasselblad offerings are all a bit heavier and bulkier.
    Contrary to popular belief, stopped down a few stops all 4 brands have equal quality glass. I have seen 20" prints from all 4 AF systems, and from most of the manually focusing 645 cameras. Some lenses have different characteristics , but I wouldn't eliminate a brand over "sharpness" questions.
     
  10. Also, a few things that weren't mentioned. You're using a 500cm. This has the older style mirror and probably has the darker focus screen. I would suggest you rent or borrow a 501cm or 503cw they have the floating mirror and much brigher focus screen. With the old style mirror when you go above 150mm the image starts to cut off on the top and the screen also gets pretty dark. There is a big difference. At the very least make sure you have the bright focus screens sorry I don't know what they're called "Beatie??"
     
  11. Thanks Dave
    I have the Acu-Matte focusing screen which is the brighter one. Beattie is similar to the Acu-Matte. One of the problems with the 500mm is that it has a max aperture of f/8 which obviously lets in much less light for focusing than. say, a 250mm f/4 or an an 80mm f/2.8.
    I do have a gadget that uses a beam for measuring distances. It is usually used for measuring room sizes and floor to ceiling heights. I'm going to give that a try for measuring distance from the focal plane, and then set an f stop and shutter speed where that camera to subject distance is right in the middle of the dof indicators. It's worth giving it a try.
     
  12. There have been several recent threads discussing focusing and Hasselblad. If you haven't seen them, they should still be in the active list.
    Perhaps the most serious problem as we get older is that we can't focus clearly on the screen itself. Acute-Matte screens are rather transparent, and if you look through them, you aren't really focusing the lens on the film plane. Even wearing glasses, I have to strain to keep markings on the screen in focus. However, this effort has greatly improved my focusing accuracy.
    It is difficult to use a WLF magnifier while wearing glasses (and likely to scratch them). The magnifiers in newer versions can be easily replaced with lenses corrected for vision. There are tables in "The Hasselblad Manual" by Ernst Wildi, which relate prescription values to these lenses.
    An inexpensive (about $100 used) alternative to the WLF is a "chimney" finder, which focuses and has either 2.5x or 3x magnification. It is a useful in the same situations you would use a WLF. The only disadvantage is that it is bulky.
    The latest PME-45 has an adjustable eyepiece, but its predecessors require a change of the eyepiece. Again, eyepieces are relatively inexpensive (used) and come in a wide range of diopters.
    There is an adapter which allows you to use "V" lenses on an autofocus ("H") Hasselblad. However, you have to cock the lens manually and use a double cable release. I'd concentrate on improving skills with your existing system or switching over completely.
    Working in the field, a good ball head and tripod is the best focusing aid you can use. It's easy to set the tension so that the camera can be moved without operating the knobs. That way you can center the split-prism then re-compose the shot. I personally dislike "rangefinder" screens, mostly because it's a big obstruction in the center of the field, and not particularly effective as a focusing aid.
     
  13. 5m away with a 500/8 lens? Won't the mirror slap scare away the birds?
    If you really need a 500/8 lens, autofocus won't help you. Even in the studio with a 110/2 lens, the H3D-II can take 1s or more to acquire focus. It's too slow for moving objects.
    At f8, I doubt the autofocus function will work at all.
     
  14. If you really need a 500/8 lens, autofocus won't help you. Even in the studio with a 110/2 lens, the H3D-II can take 1s or more to acquire focus. It's too slow for moving objects.​
    Not quite sure I understand your comment. As far as I know there is no such thing as a 500mm f/8 auto-focus lens for MF cameras. If I was discussing 35mm cameras that would be a different story. There are plenty of auto-focus lenses in the 500mm category that have max apertures larger than f/8, and I have used at least two of those lenses in AF mode. Granted there was some hunting when the subject was not clearly defined. If I were to switch to an autfocus MF camera then I would sell my 500 f/8 and probably the 250mm as well.
     
  15. I use zone focus at weddings, for faster moving objects I use 35mm cameras. Cameras are tools, you need different cameras for different subjects. Yes you may well need a 35mm with automatic focus for the birds etc. I would not get rid of my Hasselblads though. I too have vision problems, and have 4 Hasselblads, but will keep them. I use 35mm gear sometimes, not for portraits though.
    You need several different tools in your toolbox, screwdrivers, tapemeasures and saws and sometimes even hammers.
     
  16. You have slow moving targets - the birds are not flying; they are preening. Use a faster film, such as Kodak 400 NC, Kodak 400 VC, Kodak Tri-X 400, or one of Fuji's or Ilford's 400 ISO films. Then the depth of field will be greater and the focusing will be less critical.
    Steve
     
  17. Stever
    Just to be sure I am interpreting your comment properly, I am assuming that you mean that by having faster film I can stop down to f/8 or even smaller more so than I could with an ISO100 speed film?
    Thanks!
     

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