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Chrissie

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Everything posted by Chrissie

  1. I like the top one best, because the object is sharp and against a motion-blurred background, which really conveys the impression of speed. Very well done! The center one is obviously a slow fly-by, as you can tell by the downward deflected flaps. ;-) It's also nice and in focus, however against an empty background. Unlike the "birds in flight" category, with a human pilot you have the advantage that you can pre-arrange such slow fly-bys, which gives you a beforehand knowledge of where and when it's going to happen, which helps in avoiding camera shake.
  2. Been there. It sounds really tempting, getting an 83x zoom which extends to 2000mm equivalent, for less than US$ 500,-. Don't expect any miracles, though. I recently bought a Nikon Coolpix P900 for my wife. We tested it during a one day hike in the alps, and found the image quality to be exceptionally poor, at the very long end. So much so, that we eventually decided to sell it (at a loss, of course, with a shutter count of only around 50 or so.). Maybe i am spoiled from the image quality of a full frame, but in my view there is no point in taking pictures which you hate to look at. My wife now has a Sony RX100, in the "mark Va" variant. For the very same reason as above I opted against the "mark VI" variant, which has a longer reach, but a poorer image quality. P.S.: see this for a "caveat" description of the Nikon Coolpix 900: I don't see how having to use a tripod would work well enough when trying to capture small, fast flying objects.
  3. ... is not dependent on the lens alone. The body (sensor, processor) have a big impact on recognizing, whether an image is sharp or not, and generating the appropriate commands to the lens to move glass in the proper direction. The former is obviously a function of the body itself, while only the latter depends on the lens. Also, when you're talking about fast moving flying objects, the risk of motion blur from body/lense shake is always present, in addition to motion blur from the fast movement of the object itself. So you will need good in-body stabilization, preferably complimented with in-lens stabilization, too. When you go for long-reach lenses, the rule-of-thumb tells you to use an exposure time of 1/4th of the reach, or faster. For a 400mm lens that would be 1/1600th or faster. To avoid malinvestment or disappointment, I'd recommend to rent and try the lens of choice for a weekend, before you decide to buy it.
  4. Chrissie

    NEW Sony a9 adopter

    Nice introduction. Welcome and enjoy your new toy. Good choice.
  5. Have a look at this comparison in the lens database of dxomark. They seem to be on par in the "sharpness" subcategory.
  6. Chrissie

    Solar Imaging

    I regret to hear that. But, provided you can still drive around, or have someone who can take you somewhere, it's always worthwile to get to a position as high up as possible for any kind of celestial observations. Because the lowest parts of the atmosphere tend to be the "thickest", haziest, foggiest and most polluted. It gets better the higher you go. For night sky views (stars) and/or shots it's advisable to select a place as far away from any artificial light source, like human dwellings. Good luck with your recovery.
  7. Chrissie

    Solar Imaging

    Living in a valley implies, you are surrounded by mountains. Have you ever tried to climb one of those mountains and shoot from there? Note my tagline ;-)
  8. Chrissie

    Sony Zeiss 55mm f1.8

    Ian, I've temporarily uploaded some sample pictures at full resolution and maximum jpeg quality, taken with this lens on my a9, onto my flickr account. I will delete those after a week or so. It's a great lens in absolute terms, and also great value for the money, too. Did you see it's rating on dxomark?
  9. This limitation doesn't exist, if the a7riii user manual can be trusted: If you run into an ISO limitation regardless, maybe you have set an "Auto ISO range" limitation. See the "Hint" on this page for details.
  10. @JCC: thanks for your interest, and I'll try to deliver: If something is unbalanced about an axis of rotation, you need a torque to offset this imbalance. A torque in the physical meaning is defined as the product of force times leverage. (A force being generated by a mass times gravitational acceleration, btw.). its SI unit is [Nm]. Suppose you have an imbalance which requires a countering torque of 10Nm, then you could create that countering torque by applying a force of 10N at a distance of 1m from the axis of rotation, or by applying a force of 1N at a distance of 10m, or by applying a force of 100N at a distance of 0.1m. All these combinations will generate the same countering torque of 10 Nm. That's the static part. When determining the moment of inertia, you have to compute the mass times the (distance from the rotational axis squared). See this for the math involved. Lets consider the above case of an imbalance of 10Nm. If you counter that by a weight of 100N at a distance of 0.1m, the moment of inertia = 100N * 0.1m * 0.1m = 1N*m^^2. If you counter that by a weight of 10N at a distance of 1m, the moment of inertia = 10N * 1m * 1m = 10N*m^^2. If you counter that by a weight of 1N at a distance of 10m, the moment of inertia = 1N * 10m * 10m = 100N*m^^2. This is the reason, why flywheels concentrate their mass at the perimeter, connected by mere spokes to the axis of rotation. Source: https://dqbasmyouzti2.cloudfront.net/assets/content/cache/made/content/images/articles/flywheel_721_420_80_s_c1.jpg Or consider a tightrope artist, using a long pole with little weights at its end, to keep his balance. Source: https://upload.wikimedia.org/wikipedia/commons/c/c0/Samuel_Dixon_Niagara.jpg
  11. Adding counterweights obviously adds weight, which probably sounds trivial, but there's more to it. You will achieve a static balance that way. But you're putting a drag on the dynamic behavior of the gimbal, because you're increasing the total moment of inertia, which tries to resist any rotational acceleration. I would always prefer to statically balance my setup by shifting the existing gear into the position necessary for balance, rather than maintaining a position and adding counterweights. That said: if you can't avoid adding a counterweight at all, it's preferable to add a bigger weight close to the axis of rotation, rather than adding a smaller weight far away from the axis o rotation. Again for dynamic reasons. I can elaborate on that if there's interest.
  12. Well thanks, @Lagrimon, for this information. But I still wonder about the cause-effect relationship between silent shooting and the loss of color-depth resolution.
  13. Very interesting! Do you have a source for that information? Because I wonder how turning off the sound would cause the color depth to decrease.
  14. Chrissie

    EVF Shot Review

    This is a standard function for most Sony cameras. For an a7riii, see this.
  15. If you're located somewhere in the EU, you may want to try the following hardware comparison site: https://geizhals.de/?cat=monlcd19wide&sort=bew You'll find some 70+ criteria to narrow down your search, along with an individual comparison option of the 3 to 5 "finalists", a selection of possible dealers with customer satisfaction history, user comments, test results etc.. Even if you're not from the EU, this might help you in the decision which one you'll want to go for. Where to get it from is of course still up to you.
  16. I have a 128 GB card in my A9, so cannot report actual experience. No issues with the 128GB card so far. From a technical point of view: Since the technical specification of SD cards v2 is from 2007, v3 from 2011, and both a9 and a7riii are from 2017, I would naïvely assume, that both cameras implement the full SDXC standard, which allows for up to 2 TB. I'm not aware of any additional (lower) limit imposed by Sony. From a practical point of view: why would you want to use such a huge card anyways? a 512GB card is more expensive than 2 cards of 256GB, which are more expensive than 4 cards of 128 GB, and so on. 64 GB is sufficient for 1.000 images of uncompressed raw + jpeg. By extension, 512 GB would be good for 8.000 images. You run an extended risk of loosing up to 8.000 images, if something goes wrong with one huge (521GB) card. Continuous video recording is limited to a maximum of 29 minutes, because of the 4GB file size limit, and a 64GB card provides already for up to 1 h 15 Minutes of video at the highest quality settings. And then there is the overheating problem when continuously recording video for an extended time. I'm honestly curious about your use case.
  17. I would call this a premature conclusion. There's a whole variety of different microphone types for different uses around. Unfortunately neither did you specify which microphone(s) you have tried, nor could I find any specification in the technical data ("audio" section) of your camera which type of microphone your camera requires. Note however, that Sony does offer several microphone adapters to connect external microphones to your camera, which are "sold seperately".: Just because a plug is mechanically compatible, i.e. 3.5mm minijack, doesn't guarantee that plug and socket are electronically compatible as well. For instance, 3.5mm jacks come in varieties of 2, 3, 4 or even 5 contact surfaces. See this for more details. How true. Maybe you can still go back to your dealer and ask for advice.
  18. An utterly cheap way to try, if this theory holds any water would be, to attach the camera directly to the gimbal, without the grip. You would very quickly find out, if this gimbal lives up to its touted performance. The external battery pack would then just add the additional operation time to the whole combination, if you find that the gimbal itself is worth the effort and extra expense. (I always try to keep financial risk low).
  19. Any gimbal needs to be balanced about all three axes of rotation, before you can expect smooth operation. I may be mistaken, but I believe, a battery grip is attached via a screw to the tripod thread of the body. In return it provides its own tripod thread at the bottom of the battery grip. It sounds like you are using the "new" tripod thread at the botton of the battery grip to mount body + grip to the gimbal. This lowers the center of gravity of the whole unit down from the optical axis, and by looking at at video tutorial of how to balance this particular gimbal it seems, like there is not enough adjustment room for complete balancing of Body+grip about the pitch axis. Your camera has become top-heavy by mounting a battery grip to its bottom. I would try an external battery pack instead of a battery grip, to avoid putting constant load on the pitch-servo to maintain a level orientation of an otherwise unbalanced body-grip combination.
  20. Chrissie

    AF System

    Post some sample raw images with full exif included, for instance on flickr. Before that, anything would just be guessing.
  21. On the one hand I'm glad you feel helped, but on the other hand it looks like my explanation still wasn't thorough enough: Indeed, 5120 x 2880 is a really nice resolution, but this is still less than your raw images at 6000 X 4000 require. So viewing a full size picture at 100% would still make this image "overlap" the available screen space in both width and height, and you would have to pan around a little bit to view it all. You didn't mention which OS and which application you are using. 27" iMacs aren't the only ones using that resolution.
  22. Your A7iii has a 24MP sensor, and raw images are 6000 Pixels wide by 4000 pixels high. How much screen space those occupy when viewing at 100% depends on the resolution [Pixel] of the screen you use. If, for instance, you have a screen that has a horizontal resolution of 6000 pixels and and a vertical resolution of 4000 pixels, a 6000 by 4000 pixel image would cover the full screen if viewed at 100%. If a very hypothetical screen had 12000 pixels horizontally and 8000 pixels vertically, your 6000x4000 image would cover only 1/4th of the available screen space. (1/2 its width by 1/2 its height = 1/4 screen). And so on. To further dig into this, I would do the following, in the sequence as given. And please excuse if I propose something obvious: verify that the camera is indeed shooting raw. Raw images are always 6000by 4000, whereas jpeg can be configured in terms of size and quality. verify that you are indeed opening a raw file. These have the '.arw' filename extension. (At least on my a9). Look up the technical specifications of the screen you use. Particularly its maximum screen resolution in [pixel]. verify, that your viewing program (which one are you using?) has its zoom settings indeed at 100%. If all this doesn't help, please report back the details of your findings. Would be helpfull if you could post a raw image on flickr, also for your second question re. sharpness. Good luck.
  23. Chrissie

    A7Rii 4k 60fps mode?

    The short answer is: No, not now, and there never will be. It's a hardware limitation of the camera, which can't be overcome by software/firmware. You are asking for something which even the A9 can't deliver. Basically the intended resolution (i.e. 4K) times the frame rate (i.e. 30fps) yields a data rate. And there is a maximum data rate at which the camera can output a data stream. For both A7R2 and A9 this is 100MB/s. If you prefer a higher frame rate, you will have to reduce the resolution of the video. There are many video modes on the A7R2 which allow higher frame rates, just not @4K. See this, for more detail. Sections "Recording (movie)", headings " Image Size (pixels), NTSC* " and " Image Size (pixels), PAL", respectively.
  24. In another thread @tinplater mentioned, that he is shooting jpeg, not raw. This is also, what the EXIF of the Golfer picture on flickr says. JPEG is a format which uses lossy compression. These lines in the sky are compression artefacts, in my view. When comparing the size of the downloaded jpeg-file (210 kB) to the filesize of an uncompressed image (2732 kB) of the same dimensions (1024 by 683 Pixels), I arrive at a compression ratio of ~13, which is where you can definitely expect to see visual artefacts of compression already. Note to self: assist @tinplater in debugging his file download from camera issues. It is a shame having to forgo the benefits of raw shooting and processing because of something probably very simple.
  25. I would like to add another consideration to this topic: it's actually the combination of body and lens, which ultimately determines the outcome. The lens which the TO is talking about, has been tested to deliver a "PMpix" value of 25, which I interpret as a perceived resolution of 25 Mpixels. And this was tested in combination with a 42 MPix sensor (A7R2). I would assume, that on that body/lens combo the lens was the limiting factor. OTH, the A7iii of the TO has a sensor of 24 MPix, and I would likewise assume, that a sample lens which has been tested to deliver an P-MPix value above 40 on a 42 Mpix sensor (A7R2/3) pretty much exhausts what the sensor of a A7R2/3 can resolve. But the same lens would still not be able to push the maximum resolution of a 24 MPix sensor, like in the A7 iii, upwards, beyond 24 MPix. In the latter case, obviously the sensor limits the available resolution. To sum this up: the lens which we are talking about seems to be a near-perfect match to the A7iii body, as both have their limits pretty much at the same 24-25 MPix range. Maybe @wm17959 can post (or link) a picture of maximum sharpness which he was able to achieve, and let owners of that lens do the judgement.
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