Patent: Canon RF 90mm f/2.8L IS Macro & RF 100mm f/2.8L IS Macro

[koenkooi]

I wonder how many MP-E 65 users actually use it primarily in the field? I don't think it was really designed as a field lens, it really is far more at home clamped to a serious tripod at home. Once you get down to 5x you're pretty much required to stick to f/2.8 because of diffraction which means your depth of field almost doesn't exist, so unless you're shooting perfectly flat things you absolutely need to stack, and that's no fun out in the field

I primarily use it outside, in the 1x-2.5x range, so diffraction isn't an unsurmountable problem. As for tripods, I don't like them for the MP-E when I don't focus stack. When chasing creatures I often have to poke the lens inside a plant or bush, getting such an angle with a tripod would be impossible.

 

[Chaitanya]

There are so many different things that specific users want, but so little time to do them all. I expect Canon to try and hit as many specialized uses as they can in the next 2 years, and a true Macro lens should be one of them. The 35mm is not a true 1:1 macro, and 180mm is probably to physically large. 90 - 120 mm might be the sweet spot.

True, these two lenses shown in patents will be bread and butter macros for Canon just like the EF 100mm f/2.8 duo have been. For photographing butterflies having that 180mm macro even if its f3.5 or f4 combined with EOS-R sized body(just add IBIS to make lens compact without IS) would be a good combo for butterflying. Pretty sure at this point we won't see replacement to Canon's current EF 180mm L lens.

 

[Drainpipe]

I wonder how many MP-E 65 users actually use it primarily in the field? I don't think it was really designed as a field lens, it really is far more at home clamped to a serious tripod at home. Once you get down to 5x you're pretty much required to stick to f/2.8 because of diffraction which means your depth of field almost doesn't exist, so unless you're shooting perfectly flat things you absolutely need to stack, and that's no fun out in the field

I think you would be surprised. While the MP-E is great on a tripod, it’s an excellent field lens if you have some practice with it. With the MT-24EX/MT-26RT it’s one of the most convenient solutions I’ve ever used since the flash heads move with the front of the lens.

While it is a good lens at 5x, I would say that there are much more capable microscope objectives that also cost less. Yes, you lose aperture control, but again diffraction is such an issue you didn’t have it to begin with really. I’ve found that Nikon objectives are reasonably priced, very sharp, and relatively distortion-free. Not saying that the MP-E can’t be used for this, but I think microscope objectives provide a much better result. I’ve stacked quite a few times with both, and much prefer the microscope objectives.

Attached is my microscopy rig, of course without lighting and subject. I use a specimen manipulator to move the subject as opposed to the camera. I’ve also attached one of my best results with it.

This all being said, and trying to stay on topic, this patent definitely isn’t for the MP-E’s successor. It is probably a workhorse lens that Canon could also sell to the masses as a good portrait lens as well. From my original comment, it’s just wishful thinking

 

[3kramd5]

How about focus at infinity, take a picture of a small light source a known distance from the sensor plane and measure the diameter of the resulting bright circle?

If you cannot get hold of a true point light and don't know the expected size (because you don't know the real focal length), take two identical ones at a known distance from each other and you have a scale reference so you can compensate for the size of the light. Two 3mm LEDs on some perf board would suffice.

If focused at true infinity, the horizontal image angle should be 2*atan(26/(2*f)) for a rectilinear lens and close to image centre, magnification of oof light sources at 50*f distance become small enough (roughly 5% of image height for f/2) that distortion effects on reasonably modern lenses become smaller than the precision you get from counting pixels.

I like the idea, but I imagine there would be quite a bit of uncertainty in the apparatus (given that we are talking about f number to the hundredths place).

 

[Don Haines]

Attached is my microscopy rig, of course without lighting and subject. I use a specimen manipulator to move the subject as opposed to the camera. I’ve also attached one of my best results with it.

Nice shot! Also, i like your rig..... gotta love bellows and rails

 

[Don Haines]

True, these two lenses shown in patents will be bread and butter macros for Canon just like the EF 100mm f/2.8 duo have been. For photographing butterflies having that 180mm macro even if its f3.5 or f4 combined with EOS-R sized body(just add IBIS to make lens compact without IS) would be a good combo for butterflying. Pretty sure at this point we won't see replacement to Canon's current EF 180mm L lens.

I have been using my P/S camera lately for “microscope mode” with auto focus stacking it works surprisingly well, but it is no substitute for the 100L. If the new version is even better than the old one, then it will be a fantastic lens.