nerwin said:
Canon has those close up filters that Bryan Peterson loves.
Yes, Canon has the 250D and the 500D. Nikon had the 5T and the 6T. These are two-element, achromatic optical "lenses" mounted in a high-grade filter ring. They are much better built than the simple, + diopter, three-filter sets available at pawn shops for $8-$12 per set, almost always found in a small leather case with a snap-flap. Two-elements
achromats use two types of optical glass, like crown glass and flint glass, to help eliminate chromatic aberration: these are NOT just "magnifying glasses", these are high-grade, precision-made, carefully designed
two-element lens systems.
Most people have no actual experience with these types of two-element close-up lenses. I have the Canon 500D, and it's pretty good. Mine's a 77mm diameter one, and I've used it on 70-200 and 300/4 lenses. It's pretty good.
Following a tip from Nikon lens expert and nature photography expert Bjorn Rorslett, on his zoom lens evaluations page for the 100-300mm f/5.6 Nikkor lens
Zoom Lenses For Nikon 'F' Mount: Telephoto , he writes:
"
The real surprise of the 100-300, however, comes when you put a close-up lens onto its front threads. I employed my standard Nikon 6T (reverse-mounted) and was absolutely floored by the high quality close-ups produced by this combination. High image sharpness and contrast, perfectly flat field, and virtually no CA are features you associate with an expensive Micro-Nikkor, not a makeshift combination of a achromatic attachment and a consumer zoom lens. Food for some real thoughts."
I had a 100-300/5.6, and once I located a used 6T, I bought a
62-62 filter reversing ring, and tried it on the lens. He's not exaggerating. I shot some photos of currency taped to a wall: the optical quality is outstanding, and the field is perfectly FLAT across 24x36mm, sharp, high contrast, and has no color fringing. Together, these two items, a used 100-300mm f/5.6 and a more-expensive 6T would likely set a guy back $100 for the lens and $150 for the 6T close-up lens--from the right seller.
One nice thing is that wide-open at f/5.6, the diaphragm shape is perfectly rounded, since no blades cut off any of the light.
The 6T was designed back in the day when Nikon's mid-range and higher-grade zooms used 62mm filter diameters, and the 5T was for the many,many,many 52mm diameter Nikkors.