I hear you, but the 800mm F5.6 is a full professional lens, built like a tank and with the best optics, full weatherproofing, hood, tripod collar and handle, and I think it even comes with a flight case. That's a very different kettle of fish to a budget "telescopic" design such as the 600mm F11 and 800mm F11, and what I'm suggesting is a 800mm F8 based on the budget/telescopic concept. I think there would be a sizeable market among birders for such a lens, - a lens that would sell in thousands worldwide rather than hundreds, and I think it's feasible that it could sell for around £3000. Limited weather-sealing, no hood, no tripod collar, no flight case, no soft case, fixed F8 aperture, polycarbonate barrel.
You've supposedly been a member of this forum since 2018 - are you seriously saying you haven't been exposed to Harry's comments (and claims) in the past?
An increasing reliance on in-camera post-processing would be a start of a very bad trend in my view. A camera is an expensive optical device with a cheaper and releatively p**-weak, limited and dedicated microcontroller, while a smartphone is a very costly, powerful pocket personal computer with a less expensive camera.
1:2 or 2:1? I'm really liking the 1.4:1 on the RF100, I don't need to swap to the MP-E65mm as often. But having only half macro on a 180mm would be limiting, I'm mostly between 1:2 and 1:1, especially with the smaller butterflies and damselflies.
How about the Canon EF 100mm L Macro on a APSC (160mm equiv) with a Raynox DCR-250 2.5x lens on the front?
No, I do not see donuts looking at the scene, but will see them looking through the viewfinder, and want to see them on my picture. I bought a catadioptric lens, knowing there will be donuts.
1:2 (half life size) is enough for me, for butterflies, beetles, dragonflies, grasshoppers, small reptiles and amphibians etc.1:2 or 2:1? I'm really liking the 1.4:1 on the RF100, I don't need to swap to the MP-E65mm as often. But having only half macro on a 180mm would be limiting, I'm mostly between 1:2 and 1:1, especially with the smaller butterflies and damselflies.
Having 2:1 on a 180mm with IS with be great, but likely far out of price range I'd be comfortable with
I don't have an APS-C body, although I'll probably jump on the "R7" if it lives up to expectations (for bird photography).
True that you have to kick the ISO up if the target is moving, but the stabilizer is very good, so for non-moving targets, I find I can drop the shutter speed more than I expected and still get sharp images. I am using the lens on an R5, and the IBIS may be helping, but conventional wisdom suggests not that much. And, yes I noticed the elliptical bokeh balls, but bright highlight points are not all that common in 800mm scenes and I don't mind them in any case. At least no pentagons or onion rings.
I think an F/8 design would get some pushback if it didn't have an iris or an ND, so it would be substantially more expensive than the f/11, but I agree that it could be in the ballpark of the EF 100-400. I wonder how many folks would whine about $2grand + for an f/8 lens. Frankly, I think that 1200 f/8 mirror in the OP would be pretty cool with AF and IS. Once again, the DOF is so small at 1200 that you are not going to see doughnuts in that many images.
I can't see any space for an 800/8 without high end quality if a smaller, lighter, cheaper only-one-stop-less-bright is already available. A high spec 400/4 would have the same front element diameter and be far more useful, and with a 2xTC give 800/8. 400mm is a nice lens for BIF and gives a generally useful field of view. I'd get one, especially if very light and close focussing.
Yes, a 400/4 and 2x would be a better and more versatile option, but that would be looking at a 5 figure sum, whereas a fixed aperture 800/8 (as described) would be feasible for less than 3K. All academic of course, because Canon are unlikely to prioritise such a design. A pity, because an extra stop of light over the 800/11, and a potentially affordable price, would I think make it very popular with birders. Not many of us can afford, or can justify, 5 figure optics.
A 5-figure sum for a 400/4? That's more than £10,000. Nikon's 500/5.6, which is only marginally smaller is only £3000 or so.
I think these new cats are about size and price. Note that the design appears to have flat glass at the front and not a doughnut lens, so the only large optic in the whole thing is the mirror and it appears that is spherical, so not hard to grind.
The secondary mirror is typically glued to the back of the front element. In this case, the front element appears flat and the diagram shows the light rays coming straight in to a mirror of the same diameter. I did not mean that the lens would not have doughnut bokeh, but rather that the front element would not be ground lens of doughnut shape, which is typical of most cats (and the mirror is typically smaller than the front element).
My suspicion is that these cats, if they actually get into production (which I doubt), would be rather more expensive than you think.
