Another combination that gives a 1:2 (measured 1:2.06) photo at 48 inches working distance, is the Nikkor 300mm f/4E PF ED VR lens with the Nikon 20E III teleconverter attached between this lens and the Nikon D500 camera.
Although I believed the 20E III TC would not give as sharp a close-up photo as the 17E II TC, my curiosity got the best of me. Therefore, I proceeded to photograph my resolution chart with the 20E III TC attached to the 300mm f/4E PF lens and Nikon D500 camera.
As I have said before, the reason I am pursuing this path, is to find a combination of photographic equipment that allows me to take near close-up photographs at a longer working distance, so that I do not have to kneel on the ground. For me, a 1:2 photograph at 48 inches is a lot easier than at 16 inches using the Sigma APO MACRO 180mm f/2.8 ED lens, or at 10 inches using the Nikkor 105mm f/2.8G lens.
I photographed my resolution chart (described in my June 9th post under LVF) at an effective aperture of f/8, and apertures f/11, f/16, and f/22. I did f/16 and f/22 out of curiosity as to how much diffraction sets in.
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Note - For those who have not read my past posts, I used my Nikon D500 camera with this lens and teleconverter. Nikon cameras records "effective aperture" when the lens is close-up at large aperture openings (f/4). In my case, when the lens is set at f/4, the camera reports an effective aperture of f/8 for a 1:2 photograph using the Nikkor 20E III TC. If this lens and teleconverter were attached to a Canon or Sony camera, these cameras would report an aperture of f/4, and not report the affect of light loss within the lens at these close-up settings (although, the exposure will be correct for the loss of light).
Again, the following 4 photos are for those who have not read my past posts.
This is a photo of the computer generated resolution chart that was used for the 1:2 photographs:
To clarify what part of the chart is showing in the following 1:2 photographs, I have identified sections of the chart as 2nd and 3rd circular bars:
The portion of the resolution chart photographed at 1:2, is the 2nd circular bars as shown here:
I will be showing crops of the 1:2 photos which will show the smallest 3rd circular bars:
Some dimensions are shown in these two photos but are not shown on the actual print used to photograph the 1:2 photos. The above resolution chart photos are the computer generated photos, not the printed photo used to take the 1:2 photographs (the chart was printed on glossy photo paper with an Epson R3000 printer). The smallest bars and white spaces between these bars in the 3rd circular bars photo, (no. 6 on right side) have a thickness equal to the diameter of the average human hair, 0.004 inches or 0.1 mm.
PLEASE NOTE
The following photographs are of the printed chart which is not as elegant as the computer generated chart shown above; the ink pattern is shown and the edges of the bars are jagged, not straight, and the colored inks used to make black are seen (magenta, cyan, and yellow). Also, the edges of the bars at 1:2 will not be tack sharp in the following CROPPED PHOTOGRAPHS because the ink spots are 0.0002 inches (0.005mm) in diameter. Any of these extremely small ink spots on the edges will appear blurry, even for this sharp lens and teleconverter combination. Also, to repeat, the average width of the smallest printed bars is 0.004 inches or 0.1mm.
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The Nikon D500 camera was mounted on a tripod, and manually focused using live view. A Nikon MC-36 cable release was used to release the shutter. The shutter was released several seconds after I removed my fingers off the lens to reduce vibrations. At 1:2, the front of the lens was 48 inches from the chart.
I opened the raw Nef files with DxO Optics Pro and exported the files as Dng files. I did zero file adjustment in DxO, especially no sharpening. I opened the Dng files with Camera Raw CS6. I only adjusted the exposure, shadows and black sliders in CR CS6; I did not sharpen the files. I transferred the files to Photoshop CS6 and only used Photoshop to "File> save for web" to meet this forums file size requirements. I did zero adjustments in Photoshop.
Here is the photo taken at an effective aperture of f/8:
The physical size of the photographed chart in this photo is approximately 1.91 inches by 1.25 inches (2.06 times the size of the D500 camera sensor).
To get a closer view, I cropped the 5568x3712px photo to 512x512 pixels:
The printer used colored ink to make black, thus the colored ink spots in the jagged bars and numbers (cyan, yellow and magenta ink spots). As stated before, the average printed width of the smallest bars is 0.004 inches (0.1mm) , the diameter of the average human hair.
Here is the photo taken at f/11:
I then cropped the f/11 photo to 512x512px:
Upon really close examination, the f/11 photo is some what sharper than the effective f/8 photo. You can better visualize this by looking at the large black square in the two 900x600px photographs. There are very small white spots in the black square and black bars that are some what sharper in the f/11 photo; at effective f/8 some of these white spots are slightly blurrier.
Here is the photo at f/16:
I then cropped the f/16 photo to 512x512px:
There is definitely the start of lens diffraction. Compare the smallest bars at f/11 and f/16, the f/16 bars are blurred on the edges and some the smaller white spots in the black square are gone and others are blurrier.
Here is the photo at f/22:
I then cropped the f/22 photo to 512x512px:
This photo show the affects of lens diffraction.
To see more clearly at what aperture diffraction starts, I cropped the 4-5568x3712 pixel photos to 256x256 pixels and combined the 4 cropped photos in one photo:
Comparing these 4 photos clearly shows that diffraction starts at f/16. This photo also shows that this lens takes near sharp photos wide open at effective f/8, and at an apertures of f/11.
NIKON 17E II TC OR NIKON 20E III TC FOR 1:2 photo CLOSE-UP AT 4 ft.
Lets compare the two photos which show the combined 256x256px crops, 5 - 256x256px photos for the 17E II TC verus the 4 - 256x256px photos for the 20E III TC.
Here is the 5 - 256x256px crop photos that used the Nikon 17E II teleconverter:
For me, as anticipated, I will go with using the Nikon 17E II TC with the 300mm f/4E PF lens. I will let you decide which you would use if you had these teleconverters and the 300mm lens.
To repeat from my least post, my next post will compare the 1:2 resolving power of the Sigma APO MACRO 180mm f/2.8 EX lens at 16 inches, to the 1:2 resolving power of the Nikkor 300mm f/4E PF lens with the Nikon 17E II teleconverter at 48 inches, both mounted on the Nikon D500 camera.
I anticipate that the Sigma 180mm lens will be sharper because it is a MACRO lens, but how much sharper? And is it that much better considering how close you have to get to the subject for a 1:2 close-up photo?
Leon