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DSLR diehards.

Discussion in 'AP Magazine Feedback & Suggestions' started by Learning, Sep 8, 2021.

  1. EightBitTony

    EightBitTony Well-Known Member

    My 7d2 with the native EF 24-105 f/4 L just fits into my camera bag.
    My EOS R with adapter and the same EF 24-105 f/4 L just fits into my camera bag.

    I surmise by this that there's almost no difference in the size even with the adapter on the R*. Additionally, the EF to RF adapter that I have is pure passthrough and makes absolutely no difference optically or electrically, allowing the lenses to perform identically on either camera.

    So the statement you made isn't universally true. I would urge people to do a little research about the EF - RF setup before claiming otherwise.

    * I think overall, it adds about 5mm over the length of the 7d2, but this is exacerbated by the EVF which sticks out further than the viewfinder on the 7d2**.

    **Actually, I just checked, and overall, the EOS R is just over 1cm longer than the 7d2 with the adapter and lens mounted.

    EOS R + EF to RF adapter + 24-105 Lens

    eosr-size.jpg

    EOS 7d2 + 24-105 Lens

    7d2size.jpg

    As you can see, the EOS R EVF sticks out back from the camera further than the 7d2 viewfinder does.
     
  2. Terrywoodenpic

    Terrywoodenpic Well-Known Member

    But what about a native lens for a R series camera.?
    However I can not see myself ever buying an Eos R.
     
    RogerMac likes this.
  3. EightBitTony

    EightBitTony Well-Known Member

    In that case, the camera is even smaller and lighter, but the point is, that I don't need to replace my glass, I just bought a new camera and the old glass works perfectly, and the result is no bigger in real terms, and certainly not cumbersome.

    I think, but I'd have to re-weigh them to find out, that the EOS R + Adapter + EF lens is lighter than the 7x2 + EF lens.

    Indeed, and not everyone will, should or would, but I wanted to correct the misunderstanding about the EF to RF adapter. It's neither cumbersome, nor electrically or optically compromised.
     
  4. Benchista

    Benchista Which Tyler

    Years ago, Guinness did research to find out why people didn't drink the stuff.

    One of the top responses was "I've never tried Guinness because I don't like it." People's perceptions of many things often have absolutely nothing whatsoever to do with reality or personal experience. I've used quite a lot of adapters over the years to fit all sorts of lenses to other cameras, and without doubt, some of them impose limitations. Others don't - L39 to Leica M being a good example, and the ones for EF lenses on EF-M or RF cameras being another. I use an EOS R for conference work (when there is any!) and use EF L series lenses on it with absolutely no qualms. If anything, the f1.2 lenses focus better on it than on DSLRs - focus was always a little hit and miss with these lenses on DSLRs.
     
  5. spinno

    spinno Well-Known Member

    One of the advantages of Mirrorless of course is focus being achieved on sensor being more accurate than mirrors
     
  6. PeteRob

    PeteRob Well-Known Member

    Only misaligned mirrors or in terrible light. This week's AP first look of the R3 is interesting!
     
  7. GeoffR

    GeoffR Well-Known Member

    Unfortunately very true. Many people will determine that they don’t like something because they have a friend who doesn’t like it.
     
  8. GeoffR

    GeoffR Well-Known Member

    I would say the advantage is that it removes the need for a skilled technician to align the mirrors and sensors accurately. With correctly aligned mirrors focus accuracy isn’t a problem and hasn’t been for the last 60 years.
     
  9. spinno

    spinno Well-Known Member

    Advise me then why most DSLRs now have fine focus adjustment, whilst Mirrorless don't?
     
    Terrywoodenpic likes this.
  10. PeteRob

    PeteRob Well-Known Member

    Mirrorless don't need it, and properly spoken, neither should DSLRs. Whether manufacturing standards have slipped or not I don't know - could just be the wide range of lenses (new and used) on the markets. Could also be that focus adjustment is more critical with digital than with film.
     
  11. GeoffR

    GeoffR Well-Known Member

    After considerable thought, and playing with my D4:
    AF Fine tuning is applied to specific lenses, one would expect any misalignment of the mirrors to affect all lenses equally in terms of being out by a specific amount equal to the degree of misalignment. As most photographers won't own more than one copy of any given lens it is unlikely that the same error will apply to all examples but I have no way of checking (because I have never used AF fine tuning). I suspect, but again cannot prove, that the need for fine tuning arises from mechanical and electrical properties and tolerances of the lens which together result in either over or under running the commanded focused position. Something that will vary between examples and with wear over the lifetime of the lens.

    I further suspect that mirrorless cameras don't need such fine tuning because the greater processing capacity of lenses for mirrorless cameras allows the correction/s to be programmed into the lens at the factory. I assume they can accommodate for any wear.
     
  12. Petrochemist

    Petrochemist Well-Known Member

    No this is nothing to do with it. Most of the lenses I use on mirrorless cameras have NO processing capacity at all (indeed no electronics) It's simply that the focus on mirrorless cameras is done from the main sensor. making it almost impossible for the AF system/focusing aids to be even a few nm wrongly positioned. When these are separate systems as the phase AF systems on DSLRs are then alignment will be less than perfect.
     
    EightBitTony, Learning and spinno like this.
  13. Learning

    Learning Ethelred the Ill-Named

    On a mirrorless camera accurate focus is achieved by processing image data from the main (and only) sensor. The focussing loop is completely closed.
    On an SLR focus is determined either from from sensors in the base of the camera or manually from the focussing screen. No camera or lens is perfectly callibrated and focussing is partly open loop.
    Edit. Petrochemist replied while I was typing.
     
  14. Chester AP

    Chester AP Well-Known Member

    I have owned 2 Pentax APS-C DSLRs, and a variety of second hand lenses, and the only lens I have had to use the camera body's focus fine adjustment was for was a Sigma 30 mm F1.4 (a 5 minute job, after referring to the user manual). Thereafter the camera body applies this adjustment when this lens is attached, and this has greatly improved the results I get from it. I suspect that the autofocus linkage in the lens has some tolerance 'variation' compared to the ideal settings, but the amount of correction was within the range that the camera body offered, so presumably Pentax expected some lenses to have the variation.
     
  15. Benchista

    Benchista Which Tyler

    50mm and especially 85mm f1.2 lenses simply require more precision in focus when used wide open, especially on full frame bodies, than less bright lenses simply because there's less depth of field to cover for very minor focus errors. My EOS 5D IV DSLR is without question the most accurate focusing DSLR or indeed SLR I've ever used, but even that sometimes misses focus with these two lenses, despite them being adjusted. If I use Live View on this camera, they nail focus every time, because in Live View, it uses Canon's Dual Pixel AF, the same method as the mirrorless cameras, reading off the sensor. Any other lenses, I don't ever see an issue. Fact is that with AF sensors separate from the imaging sensor, with the accuracy dependent on a number of things being perfectly aligned - main mirror, sub mirror and AF sensor - all it takes is some very slight imperfection in that alignment to give a focus error with a very fast lens. At the very least, there's a lot more mechanically to go wrong that there is in a mirrorless system.
     
    EightBitTony likes this.
  16. AdrianSadlier

    AdrianSadlier Well-Known Member

    I have not read the article.

    But I am looking at "upgrading" in the next 12 to 24 months. I am an amateur, but hope to earn some income from photography in my retirement (planned for 4 years from now). I will be 68 then. I have done a handful of weddings and sold the odd print. Partially, to supplement my limited (expected) pension, but mainly to allow me to continue enjoying photography - it is an expensive hobby. I am also a gear "slut" - I buy more than I need, and not always wisely. BTW, my wife and I drive old cars - we both have Saab 9-3 convertibles, 12 and 14 years old. We got them for a really good price. I haven't bought a new car in decades and we will drive these until my retirement (and probably one of them beyond, if carbon taxes don't force us to stop).

    I am a Nikon shooter, and all my cameras and lenses are Nikon (or compatibles, with the exception of a Bronica). I have a D810 and D7000 DSLRs, a F5 SLR and a Bronica (which I hardly ever use). I have 13 x F mount lenses. I need to rationalise my kit before I upgrade. I will keep my Nikon "Holy Trinity" lenses - 14-24mm, 24-70mm and 70-200mm, all f/2.8. I will also keep my 200-500mm f/5.6 and my 105mm D f/2.8 macro. I will keep the D810 as a backup. Shutter count is about 80K. Everything else I will sell in the next 2-3 months. I will not buy any more lenses until I upgrade my camera.

    If I can afford it, I will probably buy the upcoming Nikon Z9, maybe a year or even 2 after it has launched. The delay will be because I want to see if it is as good as expected. And because it, like everything else electronic, will be on a long lead time (hence high price) for at least another year (I work in IT and anything that uses silicon chips is in supply constraint, with lead times going out, from a previous 2 weeks to up to 8 months! - prices are hardening). By that time, Nikon will have launched, and fine tuned, their second FTZ converter (the current one has design flaws, especially in relation to its usability with tripods and mounts).

    There are multiple features (speculated) in the Z9 that I want (lust after) and will suit my style of photography. Eye focus (including animal eye focus), focus tracking, higher resolution (than my current D810 - I like to crop as I cannot afford, nor ever will, a 600mm f/4). And 30 frames per second won't be bad! And reduced weight when compared to the D6 (or possibly a D850 with battery grip - these are the alternatives I considered). As I get older, the arthritis in my hands affects me more.

    Of course, all of this is dependant on me hitting my sales targets for the next 4 years, and earning enough to have a semi-decent pension - food and a roof over our heads, and being able to heat the house, come first.

    I guess I am the "perfect" target for Nikon. But am I mad?
     
  17. Terrywoodenpic

    Terrywoodenpic Well-Known Member

    That does not sound mad to me.

    I too drive an old car a Toyota Camry 2.2 extremely reliable and low maintenance cost, built like a tank.

    On the camera front I would do a cost comparison between the various makes.
    Including body and required lenses . Nikon, canon, Sony and Fuji. You might be surprised at the results. Except for Nikon you would have to sell all your existing kit.

    All four makes produce fully professional results.
     
    Last edited: Sep 19, 2021
    AdrianSadlier likes this.
  18. GeoffR

    GeoffR Well-Known Member

    The question was "why do SLRs have micro-adjustment of focusing and mirrorless cameras do not?" This applies only to AF operation micro-adjustments aren't available in manual focus.
    Sorry but DSLR AF is closed loop as long as the mirror is down, it couldn't work any other way, once the mirror starts to lift the AF is locked. We aren't talking manual focus because AF micro adjustment/fine tuning isn't involved in manual focus.
    If you are using lenses without electronics are you using AF? The discussion is about AF adjustments not focusing errors in manual focus.

    Yes, focusing on a mirrorless camera is done on the same sensor as is used for image capture and thus there is no possibility of an error in alignment but, AF uses a closed loop servo system and no servo system is perfect so there is a possibility that there will be over or under shoot of the commanded position. This will be the case with any camera whether SLR or mirrorless. The degree of error is predictable and can be anticipated by software, effectively predicting when to stop driving the focusing system to achieve correct focus.

    If there is an error in the alignment of the mirror/focusing sensors/focusing screen in an SLR the error is fixed, irrespective of the lens used AF will occur either in front of or behind the sensor by a fixed amount determined by the magnitude of the misalignment. In MF it will be determined by the misalignment of the mirror/focusing screen and it may not be of the same magnitude as for AF.

    With my Nikon D4 the AF fine tuning is applicable to each lens individually implying that a different degree of fine tuning will/may be required for different lenses. If the error caused by misalignment of the focusing sensors is constant, because the sensors don't move if a different lens is used, then I would expect the fine tuning to also be constant.

    Unfortunately (fortunately actually) I have never had to use the fine tuning so I have no idea how it is applied. However, given that, aside from sensor misalignment, the potential causes of focusing error are the same for both SLR and mirrorless I must assume that they are corrected by a different mechanism in mirrorless cameras.
     
  19. EightBitTony

    EightBitTony Well-Known Member

    They're not corrected, because mirrorless AF doesn't rely on knowing where the lens motor has moved the glass to, it just uses software to decide if the image falling on the sensor is in focus or not, if it's not, it moves the motor some more until it is (and again, this has nothing to do with electronics in the lens, it just needs an electrical connection to drive the motor). This is why Live View on Canon DSLRs ignores the micro adjustment, and just focuses on the sensor, allowing Live View shots to work with lenses that front or back focus without any corrections, on exactly the same camera that does need corrections if the focussing is done with the mirror down.
     
  20. spinno

    spinno Well-Known Member

    I assume something similar occurs in other camera makers anachronistic products...
     

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