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Chrissie

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Chrissie last won the day on February 2

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About Chrissie

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  1. I would assume, that the camera has low-light autofocus capabilities. "EV" being the abbreviation of "exposure values". So it would still be able to auto-focus, even if the lighting conditions are "X" exposure values below proper exposure. However, I'm only guessing.
  2. I have experienced the shooting of birds in flight to be one of the most demanding benchmarks for shooting at all. Looks like you are underestimating its requirements in terms of long focal reach (which in turn requires short exposure times), erratic, i.e. unpredictable movements of the birds, along with advanced continuous AF capabilities (forget manual focus with birds). In very broad terms, selling used equipments rarely gets you an adequate return on the initial investment. Therefore I would keep the A7iii and buy a used a9, to turn that bad ROI for the supplier into an advantage for you. 😉
  3. Pieter, thanks for your openness. To give Wally the Unspeakable the benefit of any doubts possible, I took the worst of all possible assumptions. The 15 Newton resisting force would only be reached, if all of the following conditions would be met. In particular, if the sample lense: had a barrel diameter of 70mm a fully compressed length of 200mm a fully extended length of 280 mm was completely hollow inside had been manufactured and sealed at the fully extended (400mm) position (i.e. rendering a pressure differential of zero between inside and outside of the lens at this position). Compressing this volume by fully zooming out (100mm position) would shrink its internal volume by 28.5%, resulting in an increase of internal pressure up to 140% of ambient pressure. So we are talking about a pressure differential of 0.4 bar, acting upon the full front surface (diameter 70mm), and this is where the 15 Newton comes from. And this is, btw, only the force acting axially, while the user would only have to apply his force to the zoom ring, which has a friction brake in itself. What I'm implying by this is, that holding this zoom lens in any position is effortless, regardless of pressure differential. We can discuss ad nauseam whether this force is difficult to overcome or not. This of course is very much subject to everyones physical capabilities and individual perception. I'm not going into that. But the initial claim, that is definitely nonsense. It states in absolute terms, that regardless of the force applied, no movement would be possible. Being a mechanical engineer by education and profession, I tend to take such statements as verbatim. Having to overcome a maximum resisting force of 15 Newton just does not qualify as a blocking obstacle whatsoever. To put this a little into perspective: Whoever handles a Sony alpha and the 100-400GM lens combo is dealing with a combined weight (force) of 21 Newton already, and nobody in their right minds would claim, that this weight is impossible to lift. This, btw, is the factual background, against which I qualified Wally's initial claim as nonsense. Thanks to everybody for their patience. I'm leaving the last word to whoever wants to have it. I'm not going to elaborate this any further.
  4. Wally, this is your initial claim: Even as you are backpedalling now, conceding the possibility of only a little movement, before being overwhelmed by air pressure forces, this still remains nonsense, as the undisputed forces generated by the pressure differential between inside and outside don't exceed 15 Newton on a zoom lens with dimensions similar to a 100-400GM. This minuscule force does not qualify as making any zoom action difficult or even impossible. Any claim to the contrary does however qualify as nonsense.
  5. Since this was a low-light situation (exposure time 30 seconds), my guess is, that the AWB did not find a proper reference point for "whiteness". If you've shot in raw format, you could correct this during postprocessing. To avoid this in future shots, you may want to experiment with manual white balance settings. Note the 2nd bullet point in the "Note" section of the above linked section of the user guide: It looks like the street light (which cast your shadow on the sidewalk) may have been one of those mercury or sodium lamps.
  6. https://www.meike-canada.com/product/meike-mk-28mm-f2-8-large-aperture-manual-focus-lens-for-sony-e-mount-nex33n56/
  7. The 70-200 GM lens is known for noticeable (actually: worst in comparison) vignetting of -1.7 EV, according to comparative measurements at dxolabs: Using a lens hood certainly doesn't help with this.
  8. I'll second that, from personal experience. And according to dxomark.com's lens database, it's actually one of the sharpest lenses around. (9th rank out of more than 7000 tested lenses).
  9. It seems like you don't plan your pictures at all. A good picture doesn't happen by accident. It consists of various aspects, including (but not limited to) the following: proper exposure (brightness, contrast) proper focus (including depth of field) proper composition (point of view, focal length, foreground, background, position of main subject within frame) Proper timing (with or without motion-blur, depending on your intention; waiting for the "right" moment, etc.) If you don't aim at anything, you're sure to hit - nothing. On a positive note: study pictures which you really like, and try to mentally decompose into each of the above aspects. Then try to imitate. This requires a solid proficiency with your gear, which you can only acquire by lots of practice. You need to plan, then act according to plan, then compare the results with your initial goal. Adjust the means as necessary. Don't adjust your goal! 😉
  10. Please answer my question regarding your 1st picture.
  11. What did you intend to show, and in which way is the result different from your intention?
  12. I tried to look it up, and my most relevant finding is this: This is the only occurrence of the word "limiter" in the linked user guide, btw.
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