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Thread: RF Native Lens Cropped vs 1.4x vs 2x

  1. #11
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    My comparison really was for me to settle it in my own mind. It is no where the level that Bryan uses.
    I wasn't surprised on the 2x. I thought it was similar.
    The RF 1.4x exceeded my expectations.
    Years ago I remember doing the same comparison in the field on my first 500mm and I used stuffed animals.
    Plus I know the EF 1.4x results are bad, I need to see if something is wrong with the extender or my method failed.
    I sent you the link, if you do not get it let me know.
    I could do the RAW but it would take a substantial amount of work.

  2. #12
    Senior Member Fast Glass's Avatar
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    I think Jpeg serves the purpose. And yes, I just looked and I got the shots. I'll check them out on my PC later tonight. And thank you for satisfying my curiosity. Lol.

    I think maybe doing it with something like stuffed animals might be beneficial since it would be more forgiving if the focus was off just a smidgen. And do some basic post processing to mimic what you would do in real life. Primarily the 2X, since the 1.4 looks very good I doubt there was any kind of user error.

    But I hear ya, it very well could be that those are indeed the results and I'm gonna have to lose some sleep. lol.

    I think I'm gonna have to do the same thing with my 300mm f/2.8. Realistically even if it is a wash I'll be using the 2x anyway just because I like framing my shots with the correct focal length and I still get to use more of my sensor.

    If it is softer, then I would have to rethink it. But the 300mm f/2.8 handles extenders pretty well so I think it will be fine.
    Last edited by Fast Glass; 03-05-2022 at 01:34 AM.

  3. #13
    Senior Member Fast Glass's Avatar
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    Thank you again HD for the full sized samples!

    For some reason I couldn't get them to edit. But I do get a better feel for the sharpness

    So after some pixel peeping they are exceedingly close in sharpness. But I cropped a portion of the chart which helped me see the differences a little bit better. These are mid frame shots, extreme corner sharpness is not of prime importance to my style of shooting but mid frame is as that is where I like to put my subjects a lot of the time.

    To my eyes the 2x beats out the native shot cropped to the same dimensions and viewed at the same dimensions. But they are exceedingly close! But if you count how much more resolution the 2X has it makes it lean more towards the 2X even more.

    Native:



    600mm with 2X:



    But the other thing about this is the 2X has far more pixels on target, and more sensor. So if you are in a situation of excellent light the 2X would have the advantage of the whole sensor's dynamic range and colors. Even with sharpness being very close. Low light, might be worth doing some testing to validate that.

    What you guys think? Which one would make more sense to use?

    Main thing is I now can sleep at night knowing it is still not worse to use a 2X extender. Even if it is very close. LOL.




    Edit, now looking at the crops. The left hand of the images look softer than the right hand. Particularly the 2X results. But the crop is from the right hand of the side of the chart. So if there was a noticeable fall off in sharpness it would be the other way around.

    Either the chart is not parallel or there is some decentering going on with the lens.
    Last edited by Fast Glass; 03-05-2022 at 09:45 PM.

  4. #14
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    The 2x comes far closer to making sense mid day with excellent light, but with all the advantages and disadvantages weighed I think for myself the window is to narrow for it to be useful. The center is more important to me than the mid, but both are needed.

    I figured I would have some corner variation. That is nothing more than a slightly out of square target and narrow DOF.

    I am curious why you couldn’t edit them. They are straight out of the R5. The files were emailed to my wok account through gmail and google drive, then loaded in Dropbox. Maybe something was lost in the process.

  5. #15
    Senior Member Fast Glass's Avatar
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    I'm not sure, I can do some functions. But extremely limited. Like NR and cropping. I know if I had the RAW files I'm sure I could edit them. But I think the Jpegs served their purpose. Update; For some reason it does this to other Jpegs that I didn't process from from RAW, weird.

    I would say if the target is off a reshoot for the 2X results VS native would be beneficial. If the mid frame is off like it is, I can see it transitioning softer towards the center of that very tiny crop (This as you know is a VERY tiny section) it means the center is not in focus by a fair amount. Which to me looks about right because it looks more than just softness. It looks OOF.

    Up to you if you want too reshoot. But I think getting it as square as you can. Getting the chart glued to something flat. Well lit at ISO 100, flash lighting. Try manual and AF. Do more than 2 sets of focusing, do at least 10 or more for every combination and aperture. If you can use a remote monitor even better. It might also be worth getting the chart printed larger for a few bucks, then you will get much clearer lines, and standing back further gives a little more DOF and margin for error.

    Then you can see for sure what is going on, right know I would say the 2X results are misleading and not accurate.

    I'll be trying to recreate Bryans setup. Minus the crazy expensive charts (Unless I can find one for significantly less than $1000 plus price tags), I'll get a big one printed out professionally and it will serve the purpose. Mounted on glass and laser aligned ect. (I do got access to laser levels to do this). Basically recreate it exactly how he has it. That way I can compare mine to his charts accurately.

    Because I got several lenses (Many more coming) that I want to know if they are focusing absolutely perfectly or not. Or if they are a good sample or not.

    But this is just me, I don't want to tell anyone what to do.
    Last edited by Fast Glass; 03-06-2022 at 09:05 AM.

  6. #16
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    All those are good suggestions for being more accurate. The narrower DOF of the 2x comes in to play and as you mentioned even gluing the target down might improve the results in some areas. Same thing on making it square. I could have worked a few more hours to make at it as precise as possible. A different printer would have helped as well.

    I do think the focus is on. I refocused every shot so I had three samples. The method I used I always have good results. Any and all shake was eliminated and I focused at 10x.

    Look at Bryans chart. I think the results were similar to Bryans. I think it is representative of what I am seeing. Toggle back and forth between the 600mm at native vs extender. The Center is noticeably softer.

    https://www.the-digital-picture.com/...mp=0&APIComp=1

    Unfortunately I can not repeat the test, and if someone asks and I could I would. I sent the 2x back. With my preferences I realized that I would not be happy with it. The RF 2x would have to perform beyond its abilities. The EF 2x III I have is hardly ever used on my 500mm. It was only useful in very rare instances, and in those instances fine resolutions wasn't as important. Also if I keep my 500mm I am good to 1000mm if needed for a certain application.
    Last edited by HDNitehawk; 03-06-2022 at 04:24 PM.

  7. #17
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    I researched it a little more after reading your response.
    The WB difference is miss leading, but also telling in that I had to add more light to get a decent result.

    I did a little PP on the 600mm 1.4x and 2x just to see what I could get.
    Initially I applied white balance to both and I have to say that the 2x is slightly better.
    But the 1.4x was shot with a higher ISO, so I went ahead and applied sharpening and and noise reduction.
    With noise reduction and sharpening on both they were fairly equal.
    My conclusion is this, you can get about the same results out of both methods. Maybe the 2x will give you slightly better in certain situations but not "significantly" better. It also depends on who is doing the processing and how a person flavors it.

    I dropped some of the RAW files in the Drop Box folder if you still want to see them.

  8. #18
    Senior Member Fast Glass's Avatar
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    Yes for sure!

    My conclusions were pretty much same for effective sharpness. Because resolution is not everything if the overall sharpness is not there. But we both knew that. LOL.

    My thought process, and I'll be doing this as soon as I get my mark III extenders on my 300mm. Is to rule out any errors in the charts. Which looking at them I do see slight alignment issues. But if even slightly canted and still holding its own. It will do even slightly better in real world were DOF rarely manifests itself on a flat plane like a chart.

    I think an interesting test would be in low light. In theory you could crop or use an extender and it give you the same noise levels at the same output size.

    But putting it to the test and see if there other variables that could influence it.

  9. #19
    Senior Member Fast Glass's Avatar
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    So after messing around with the RAW files I was impressed with what a difference doing basic postprocessing made!

    There was MUCH to much luminance noise reduction, like FAR too much! I completely mushed the details of everything. Used 0 luminance NR and chrominance and 2 color moire. There was a lot of chrominance noise.

    Second thing I did was set it to what I like in the picture style as a base which is lowest contrast highest saturation (Lower the contrast the higher the saturation I need to maintain good saturation). This is my preference for post processing. To each there own no right or wrong here.

    I applied lens corrections including maximum Digital Lens Optimizer. Reduces CA and improves corner sharpness ect.

    Sharpening is pretty fine compared to the standard sharpening setting that was one there, it was REALLY blunt and very good at all. I set it to 1.2 strength, .5 radius, 1 threshold. This is my taste in sharpening, relatively fine and not to strong.

    And of course click white balance correction.

    So, with my taste in postprocessing done, I can see the texture of the paper of both the 2X samples and the native samples! Both are very sharp and very little difference between them. There is FAR more softness in the chart than the differences between the 2X results by themselves. It is more misleading than anything else because of it, we are far exceeding the resolution and sharpness of the chart with both.

    In conclusion the 2X is FAR better than cropping and less than ideal test chart adds a few challenges to get a clear result.

    Native


    2X


    As you can see the 2X after basic post processing is looking far better than previous results, I think what was happing was there was MUCH to much luminance noise reduction and eliminating the fine details of the paper. And having the WB corrected makes it much easier to view sharpness, for me anyway.

    If this was done with ISO 100, good lighting (This lighting is to dark the exposure and enhancing chrominance noise, influencing the results.) and daylight or strobes. So idealy you have zero NR and you are seeing only the sharpness of the lens.

    Also the chart is not very fine at all, a much larger and higher quality chart would make a HUGE difference in seeing the actual sharpness of the lens. Right now I'm using the texture of the paper as a means to help measure sharpness lol. That's pretty darned sharp at that point. But if you even just look at the chart itself and the lines in particular, it is definitely pulling much more detail compared to the native results. And using the full sensor in the process.
    Last edited by Fast Glass; 03-07-2022 at 02:39 PM.

  10. #20
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    Another comparison to look at, do the same with the 1.4x.
    It holds up much better, see what your opinion is there.
    After I processed I had similar results and like I said in my last post it is better than the cropped native. I was referring to the 1.4x as being very similar.

    We are seeing the same thing.

    If I could get a chart locally available I might have grabbed one. In the past I used my pixma printer to make the chart on photo paper, it would have been better. I probably should just buy a chart. I found several online that were larger over $300. What I really need to do is replace my printer.

    For the ISO 100, for my use it is very rare that I get to shoot at that low of an ISO on that lens. Would it really been representative of real world, for some people yes, but not me.

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