Close-Up comparisons Part 1: 4500

Started Apr 23, 2003 | Discussions thread
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Ching-Kuang Shene
Ching-Kuang Shene Veteran Member • Posts: 6,225
Close-Up comparisons Part 1: 4500

Hello folks,

Finally, I have some extra time to play with my close-up stuffs, shoot some examples, and start to write the close up sections of my 950/990/995/4500 user guide. (The 2500 has already had a very simple section). The following shows you some preliminary results on 4500.

The equipment I use include a 4500, Raynox MSN-500 macro lens, Nikon's #3T +1.5 and #4T +2.9 close-up lenses (highly recommended), Nikon AF 50mm F1.8D, and Nikon AF 24mm F2.8D. The last two are for reverse-mounting close-up. Additionally, I also use some step rings, and SL-1 and Samigon FRL-1 ring lights for lighting.

First off, I'd like to emphasize that in close-up photography, the key factor is magnification rather than how close we can focus. Magnification of a setup is defined as follows: If a subject of length X has a length of Y on the image sensor, the magnification of this setup is Y/X. If X=Y (i.e., the length of the subject and its length on the image sensor being equal), we will say this setup is capable of life-size macro (i.e., 1:1). If Y > X, this setup is capable of larger than life-size macro.

Second, we need to know the size of the image sensor. I choose to use an approximation rather than its actual size. Since the sensor in a 4500 has a diagonal size of 1/1.8" = 14mm, the width of the sensor (based on a 4:3 aspect ratio) is 11.3mm. Since not every pixel of the CCD is used for image recording, the actual area for recording an image is slightly smaller. However, the difference in magnification is not significant.

The following image was taken with 4500's macro setting at its minimum focusing distance. Examining the image, we see that the recorded width is 20mm. Since the length of X = 20mm appears on the CCD as Y = 11.3mm, the magnification is 11.3/20 = 0.57X. As mentioned above, 11.3mm is larger than the actual width for image recording, the actual magnification is slight higher but not by much. So, in the macro mode of 4500, the magnification is about 0.57X.

The following was taken with Raynox MSN-500. The recorded width is 6.5mm and the magnification is 11.3/6.5 = 1.74X, a very good result. The problem is that the corner area is soft; however, the center portion is good. Keep in mind that to get the maximum magnification, 4500's lens must be zoomed all the way in. This is the way of using all close-up lenses.

The following three images were taken with Nikon's 3F, 4T and 3T plus 4T. Thus, the diopters of these images are +1.5, +2.9 and +4.4, respectively. Since the recorded width values are 49mm (3T), 37.5mm (4T) and 32mm (3T plus 4T), the magnifications are 11.3/49 = 0.23X (3T), 11.3/37.5 = 0.3X (4T), and 11.3/32 = 0.35X (3T plus 4T).

The following was taken with a 50mm lens reversed. Since the recorded width is 12.5mm, the magnification is 11.3/12.5 = 0.9X, which is close to 1:1 life size. Although this setup does not provide a magnification as high as that of the Raynox MSN-500, it is very sharp!

The next one was taken with a 24mm lens reversed. Since the recorded width is about 7mm, the magnification is 11.3/7 = 1.6X. Note that vignetting is significant. While it may be sharper than that of the Raynox MSN-500, this vignetting problem renders the reversely mounted 24mm useless.

Here are my conclusions.

(1) If you have a 4500 and need about 1:1 or higher macro, consider Raynox MSN-500 or a reversely mounted 50mm SLR lens (if you have one) first. This is because the image quality is definitely better.

(2) The use of close-up lenses, even with the good ones (e.g., Nikon's 3T and 4T), its magnification is still lower than that of the 4500 macro capability. Moreover, since we must use the maximum focal length, which usually has a worse image quality than the shorter end, the use of close-up lenses may not be as sharp as the on-camera macro setting.

(3) Since the 4500 has a quite short maximum focal length (32mm), the reverse-mount technique may not yield the best result. More precisely, the SLR lens to be reversely mounted may not have a matching optical formula with the 4500 on-camera lens. IMHO, its optical quality is considerably worse than the 50mm+200mm and 24mm+200mm combos that were commonly used by SLR shooters some years ago. This is especially true for the 24mm case. Note that the reverse-mount technique usually does not yield good results with zoom lenses.

(4) If you don't might image quality and really want to have extremely high magnification, you might want to try reversely mounting a 50mm SLR lens on the 8X CrystalVuew Shooter. The recorded width is about 1.5mm, which yields a magnification of 7.5X! However, focusing is difficult and contrast is low.

(5) The rule states that the magnification should be a/b, where a is the focal length of the on-camera lens, and b is the focal length of the reversed lens. Thus, the 50mm and 24mm cases should have 0.64X and 1.3X, respectively. However, the actual measure gives 0.9X and 1.6X, which are higher than the theoretical results. I would suggest to go with the actual values, because the theoretical values are based on ideal lenses.

Hope this helps. I will post some preliminary results of the 5000 and 5700 in the near future. All results along with other samples will appear on the close-up page of my user guides. Comments and suggestions are most welcome.

CK
http://www.cs.mtu.edu/~shene/DigiCam
950/990/995/2500/4500 user guide

 Ching-Kuang Shene's gear list:Ching-Kuang Shene's gear list
Olympus D-600L Nikon D7100 Nikon Z7 Nikon AF-P 70-300mm F4.5-6.3G +2 more
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