R5+100-500+1.4x or R7+100-500?

drsnoopy wrote:

RDM5546 wrote:

I just completed my third my third comparison shot session for collecting images from the label on the power pole near my house. I have made several small refinements in technique for each of the three test shooting days.

There is was a great deal of forum interest/attention to the use of the R5/ RF 100-500 with the 1.4X TC vs the R7 using the same RF 100-500 lens. These pictures are of a label that is over 100 feet from the shooter and all pictures are made from same shooting location.

Using the R7 and the RF 100-500 with no TC resulted in 6000 pixels on the label

Using the R5 and the RF 100-500 with no TC resulted in 3000 pixels on the label

Using the R5 and the RF 100-500 with 1.4X TC and 1.96 more pixels on the label resulted in

Using the R5 and the RF 100-500 using 451mm FL with 2X resulted in 6000 pixels on the label

Note: the 902mm was the FL because the zoom got bumped changing the 1.4X TC with the 2X TC. Also note the increased number of pixels on the label from using the 2X TC rather than the 1.4X TC.

To judge the images above for detail you should adjust them to be side by side and same physical size on your large computer screen. The R7/RF100-500 without TC and R5/RD100-500 1.4X TC are best compared side side and adjust to make both the same size.

Despite being a f2X TC resulting in the aperture to be f13 at the 904mm the image it generations is pretty competitive with R7 image using only the bare RF 100-500

Your 1st and 2nd images are what interest me, though I think the 2nd (R5 + 1.4x) is unfortunately affected by image movement (looks like camera shake). As a result I don’t think it is a useful comparison. The 1st image (R7, bare lens) is the best of the series, with numbers clearly legible. Your test shows the difficulty of creating reproducible conditions, but is a good attempt nevertheless!

All three images when observed in the entirety look to be sharp.  The label is a very  small part of the image so this extreme cropping with bigger lens hard to keep stable during the tests when conditions are not perfect.   It all depends on how much work and time you are will to spend.   I did the tests three times and all three times I reach the same conclusion.   The R7 is doing a better job that R5 on these very small subjects in the framed image.  This is a common issue for skittish little birds you can not get close too.    I am now happy with result for my use.

If forum members want a set of images they like more I suggest they do their own tests.  The R7 is better and the R5 with the 2X comes close when using the 100-500 on very small objects cropped from SOOC jpeg.   The question I pander is what happens when the crop is bigger producing more pixels that I use in my current test case.  At some     point using less cropping the benefit to the sharpness using the R7 will be gone,