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The new Cannons ...
#13
(04-16-2021, 06:28 AM)Brightcolours Wrote:
(04-15-2021, 08:52 PM)wim Wrote: The 100 mm macro, as before, is not a 100 mm lens anymore when shooting macro. Focusing distance at 1:1 is 28 cm (object to sensor) and 26 cm at 1:1.4.

That means it is a 69 mm lens at 1x magnification and 65 mm lens at 1.4x magnification. This means I will certainly not get one.

For those who like to shoot video this behaviour may be beneficial, as it may have little to no focus breathing at normal shooting distances.

Yeah.. about that.

You got those numbers from dpreview?
DPReview says 26cm MFD (1.4:1), 8.6cm working distance. 

The lens is internal focussing, as far as I know. 

DPReview says 28cm object distance at 1:1... So they gain 40% magnification with 2cm of movement (or to put it more clearly.... they gain 40% magnification with going only 7% closer to the subject)? And they say 11.2cm working distance at 1:1.
26 - 8.6 = 17.4cm
28 - 11.2 = 16.8cm.
Something is off with those DPReview numbers, and your calculations.

Canon states 26cm MFD and a lens length of 14.8cm. The RF mount has a 20mm flange distance. 26 - 14.8 - 2 = 9.2cm working distance instead of 8.6cm. So DPReview's working distance figure for MFD is wrong.

Can you point me/us to a Canon subject distance number for 1:1?

Anyway. You say you will not get one. You won't be getting the Canon EF 100mm f2.8 L USM then, either. It does 1:1 at 30cm MFD (this RF lens does 1.4:1 at 26cm MFD). Or the Canon EF 100mm f2.8 USM. It does 1:1  at 31cm MFD. Sigma's new 105mm f2.8 DN ART? 1:1 at 29.5cm MFD....

No, I won't get any of the Canon EF 100 macro lenses either. I actually owned the 100 non-L version, and wasn't too impressed by it. I would not consider a Sigma lens either, because of personal experience(s) with the brand..

In order to caculate the FL at these magnifications I used the simple lens formulas which take magnification into account. Basically for 1:1 it is very easy, especially as Canon uses MFD correctly, as in, the distance from the sensor to sharp focus plane of the object being imaged.

I know you don't like simple lens formulas, because modern lenses aren't simple, but it is nice for a comparison. At 1:1, it works out that the real MFD equals 4x the FL, so that makes it even easier Smile.

The 28 cm and 26 cm figures, actually just a little less expressed in inches, are Canon's as far as I am aware, so the math for the actual FL is simple: a little less than 28 cm divided by 4 makes it around 69 mm. I honestly can't remember where I saw the MFDs, but since I saw inches, it must have been a US article.

For 1.4x magnification I put it in my spreadsheet, where I stored the actual fomula Smile.

With macro lenses, I prefer a lens that does a lot of focus breathing, i.e., extends the barrel rather than focuses internally. It gives one several advantages, namely a slightly larger working distance to the object, relatively speaking a lot more distance from operator to object, and generally no change in rendering.

I also find that many IF lenses, especially in the macro area, don't render all that nicely, but that obviously is a matter of taste.

I therefore prefer lenses like the longer TS-Es for macro, and even some lenses a lot of people would not consider, but do actually well in macro ranges, like the old 50 F/1.2L, 135L, both with extension tubes, 100-400L with D500 anachromat close-up lens, the non-IS 70-200 F/4 with tubes, and some of the shorter TS-Es {45, and even 24) as well, with tubes.
Macro lenses I really like are the 180L Macro, and the MP-E 65 Smile. I also liked the diminuitive EF-S 60 a lot when I got that back in 2005. Sold it a year after  the 5D II was released.

HTH, kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....
  


Messages In This Thread
The new Cannons ... - by Klaus - 04-14-2021, 08:41 AM
RE: The new Cannons ... - by Brightcolours - 04-14-2021, 11:29 AM
RE: The new Cannons ... - by Rover - 04-14-2021, 07:57 PM
RE: The new Cannons ... - by Klaus - 04-14-2021, 09:46 PM
RE: The new Cannons ... - by Brightcolours - 04-14-2021, 10:20 PM
RE: The new Cannons ... - by mst - 04-15-2021, 07:59 AM
RE: The new Cannons ... - by Rover - 04-15-2021, 04:06 PM
RE: The new Cannons ... - by mst - 04-16-2021, 06:59 AM
RE: The new Cannons ... - by Brightcolours - 04-15-2021, 02:09 PM
RE: The new Cannons ... - by wim - 04-15-2021, 08:52 PM
RE: The new Cannons ... - by Brightcolours - 04-16-2021, 06:28 AM
RE: The new Cannons ... - by Rover - 04-16-2021, 07:16 AM
RE: The new Cannons ... - by wim - 04-17-2021, 01:01 AM
RE: The new Cannons ... - by Brightcolours - 04-17-2021, 10:38 AM
RE: The new Cannons ... - by davidmanze - 04-17-2021, 11:30 AM
RE: The new Cannons ... - by wim - 04-17-2021, 11:34 PM
RE: The new Cannons ... - by Brightcolours - 05-08-2021, 07:46 AM
RE: The new Cannons ... - by wim - 05-08-2021, 03:31 PM

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