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Pentax Vision

Discussion in 'Pentax Chat' started by SXH, Jul 19, 2020.

  1. GeoffR

    GeoffR Well-Known Member

    If I am honest, I really don't think Nikon thought a great deal about "Flexible program" on the top end cameras. I think they expected the cameras to be used in Aperture priority or Shutter priority, Program was included because the chip set could do it rather than as a fully valid operating mode. I have to confess that I have never used Program on any of my cameras that have/had it, I see it as a rather unnecessary addition but if you want to use it, why not.

    I would guess that the D5 and D6 do these things in the same way as the D4, which is pretty much how you describe for the D800. I haven't so much as handled a Z series camera so I have no idea how they handle it.
  2. ChrisNewman

    ChrisNewman Well-Known Member

    I rarely use Program on my D800, which has an excellent Auto ISO system. But I think it’s well worth having, unlike the “Scene modes” on my D90, which I never investigated.

    I used Program mode regularly on my D90 in limited light, because I like to bracket the exposure of digital shots (±⅔EV), so that I’m almost assured of a near-perfect exposure. But the D90’s Auto ISO takes no account of focal length, so seems of little use with a zoom lens. I decided Program mode was the best way to vary exposures, bracketing both aperture and shutter speed ±⅓EV around what I thought was ideal.

    Program mode was crucial in my choice of the Pentax Super A, as I had little confidence in my ability to set exposures in those days, and with film, no opportunity to check after taking a shot. I think the Pentax’s exposure programme was about as good as it could be for a standard lens (this was before SLRs could adjust their exposure in response to focal length), while Canon and Nikon’s exposure programmes seemed primitive and near-useless.

  3. GeoffR

    GeoffR Well-Known Member

    Actually the program on the Super A isn't as much different from that of a Nikon F5 as you might imagine. Basically both hold the aperture wide open until 1/30th in the case of Pentax and 1/8th for Nikon then stop the lens down until it hits minimum aperture, in both cases that occurs with a shutter speed of 1/1000th the difference is that the Pentax closes the aperture quite quickly until the shutter speed is 125th then less quickly, obviously the slopes of the curve are different. A better combination of shutter speed and aperture with the Pentax in some circumstances I would imagine.

    The graphs are oriented differently which doesn't help but both are available on line, simply look for the appropriate camera manual.
  4. SXH

    SXH Well-Known Member

    There's now an article concerning the new APSC model that's in the works. Pushes the 'our gear is great because we only do DSLRs' idea very strongly.

    Also a bit revisionist
    Apart from some earlier models, which we'd rather forget, that used pentamirrors.

    There's also
    Because photographers can't be inspired by a view unless it's through a viewfinder. And we all know it's impossible to compose a pic through any other kind of viewfinder. :rolleyes:
  5. PeteRob

    PeteRob Well-Known Member

    I think it is quite hard to compose using a 35 mm prism viewfinder. The main advantage is the engagement you get with the subject and it takes some effort to detach from that and look at the whole scene. I always thought a waist-level finder made composition easier - though being back to front is confusing at first. Mind you I have never used a 6x6 prism finder - maybe this is better still. I don't find the LCD screens on the back of cameras (even twisty ones) anything like as engaging to use. The ELV finders are getting good now.
  6. ChrisNewman

    ChrisNewman Well-Known Member

    In my opinion, in those simple auto-nothing-but-exposure days, the purpose of an exposure programme was (or at least should have been) to try to give a sharp photo from a hurried or casual hand-held shot, assuming the photographer had the subject in focus. There are two factors likely to prevent this. Camera shake would blur the whole photo, whilst lack of depth of field might make some subject areas unsharp. In addition to the Pentax Super A, I had brochures for the Minolta 700, Canon AE1-Program and, I think, the Nikon FG. I think the Canon and Nikon programmes were identical, using f/5.6 at 1/125th, while the Pentax matched 1/125th with f/8, giving slightly more depth of field. But if the light fell, the Canon and Nikon programmes traded 1 aperture stop for 1 shutter speed stop, so the shutter would be open for four times as long while depth of field was halved. With the 50mm f/1.8 or f/1.7 lenses with which such cameras were usually sold, these exposure programmes didn’t open the aperture fully until about 1/12th sec, when camera shake would be a major problem. I remember one of the brochures (I think it was Canon) explaining that a light warning of camera shake would appear, yet at this stage the programme would still be well short of opening the aperture fully. What good is an exposure programme that doesn’t open to maximum aperture before camera shake becomes a problem? In contrast, the Pentax Super A traded 2½ aperture stops for 1 shutter stop, sacrificing slightly more depth of field than shutter opening time as the light became poorer, and giving full aperture at about 1/40th sec, which might still be usable hand-held.

    Unfortunately most current DSLRs have reverted to the primitive Canon/Nikon type programme, except for increasing the aperture and shutter speed when focal length is increased. However, with auto-ISO programmes, image stabilization and the ability to check and re-shoot on site, the risks of a shot being spoiled through casual shooting with the camera in aperture priority are much reduced, and the preponderance of zoom lenses with smaller maximum apertures make these basic exposure programmes now seem less of a liability. Anyway, programme shift means the programme mode can no longer be relied on to give a sensible combination of aperture and shutter speed, as that might have been biased for a previous shot. Instead, it seems to have become just another way of achieving a desired balance between shutter speed and aperture, along with aperture priority and shutter priority.

  7. GeoffR

    GeoffR Well-Known Member

    As I said, I don't really see the point of Program mode; you let the camera select the aperture and shutter speed than you shift that in favour of depth of field and then apply exposure compensation. Alternatively you shift the result in favour of shutter speed and apply exposure compensation. If one knows the shutter speed or aperture required, why not just use the appropriate priority? Alternatively, why not develop a software tool to let the photographer create their own Program curve? The current curves, for want of a better term to describe a ramp, are crude. If manufacturers can't do better than that, why bother?
  8. Chester AP

    Chester AP Well-Known Member

    Perhaps the user is the software tool.
    Isn't this what we used to call understanding the process and experience of using the hardware, and applying both to manual settings?
  9. GeoffR

    GeoffR Well-Known Member

    You may have a point. As I said I have never used Program mode on any of my cameras that had one, which goes back to 1990 when I bought an F4. As far as I can see the actual curves haven't changed.
  10. ChrisNewman

    ChrisNewman Well-Known Member

    I agree in principle that I can’t see the point of anything more complicated than the single, fixed “turn on and forget” programmes such as were found in the earliest SLR’s to include a Program Mode. If you’re going to stop and think, you may as well set the precise aperture or shutter speed you want. Yet in practice, as I wrote earlier, with my D90 that lacks a sophisticated Auto-ISO programme, I find using Program Mode and Program Shift is the best way to balance aperture and shutter speed across bracketed exposures. With my D800, I can rely on Auto-ISO to minimize the risk of camera shake at my chosen aperture.

    Done_rundleCams likes this.
  11. Pontoneer

    Pontoneer Well-Known Member

    That's where I am - entirely happy with my K-1 , K-3 , K-01 , and although I got rid of most of my film bodies I kept one LX and the KM which was my first Pentax back around 1975 .

    I saw something on the web to the effect there was a new camera coming out , so dropped by for a look .
    Done_rundleCams likes this.
  12. Done_rundleCams

    Done_rundleCams AP Forum Ambassador to Canada

    What ... Who uses Pentax DSLR's any more ...

    SNWJunJRSa.jpg Jun18-20-AP-Thurs-JSGP3651 copy 2.jpg Jun17-20-AP-Wed-JSGP3327 copy.jpg Jun17-20-AP-Wed-JSGP3330 copy.jpg Jun17-20-AP-Wed-JSGP3364 copy 2.jpg

    Who uses Pentax SLR's any longer ...

    June24-20-AP-Wed-000014 copy.jpg

    Jun27-20-AP-Sat-000021 copy 2.jpg Jun27-20-AP-Sat-000025 copy.jpg Jun27-20-AP-Sat-000031 copy.jpg

    oh yeah, I do ;)

    From June 2020 :eek:



    steveandthedogs likes this.

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