Architect1776 Loc: In my mind

This is an interesting claim.
Seeing as Hasselblad and Leica the only 250mm lenses I know of, and believe they are not current lenses, outside some view camera lenses. Were there any other 250mm lenses made for 35mm cameras? So the claim below is interesting like saying the fastest 24 wheel bicycle in the world.


THIS 250MM F/4.9 LENS IS THE “WORLD’S SHARPEST” AND HAS INTERCHANGEABLE CAMERA MOUNTS
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February 21, 2019 by John Aldred 7 Comments


It’s a pretty bold claim to say you’re the world’s something-est anything. But that’s what William Optics are doing with their new Redcat 250mm f/4.9 lens, hailing it as the “World’s Sharpest” 250mm lens ever made for full frame cameras. Which, to be fair, is possibly true, as very few 250mm lenses have ever been made for full frame cameras.

Interestingly, though, it’s based on a Petzval design, which is typically more associated with “swirly bokeh” than sharpness. But this lens uses a pair of synthetic fluorite elements to correct those issues in an attempt to produce sharpness across the entire frame. At least, that’s what their Kickstarter campaign says.
THIS 250MM F/4.9 LENS IS THE “WORLD’S SHARPEST” AND HAS INTERCHANGEABLE CAMERA MOUNTS
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February 21, 2019 by John Aldred 7 Comments


It’s a pretty bold claim to say you’re the world’s something-est anything. But that’s what William Optics are doing with their new Redcat 250mm f/4.9 lens, hailing it as the “World’s Sharpest” 250mm lens ever made for full frame cameras. Which, to be fair, is possibly true, as very few 250mm lenses have ever been made for full frame cameras.

Interestingly, though, it’s based on a Petzval design, which is typically more associated with “swirly bokeh” than sharpness. But this lens uses a pair of synthetic fluorite elements to correct those issues in an attempt to produce sharpness across the entire frame. At least, that’s what their Kickstarter campaign says.

Designed primarily for astrophotography, Taiwan based William Optics is no stranger to such application. Their About section says that they’re “one of the world leaders in short-tube, highly-portable refractors”, producing equipment at both entry-level and high ends of the user spectrum.

The new lens, known as the RedCat 51 APO 250mm f/4.9 is a fast Apochromatic refractor that’s both small and lightweight with a full frame 35mm field of view. As mentioned, it uses a Petzval design with synthetic fluorite elements to produce a flat field image and overcome the issues inherent with the Petzval design.

Looking at the sample photos on the campaign, as well as this footage shot on the Panasonic GH5, it certainly does seem to live up to its sharp claim. Whether it’s the sharpest or not will have to wait until we can see some real side-by-sides, but for now, I think it’s definitely sharp enough.

Of course, the Panasonic GH5 is a 2x crop body, not full frame. So, again, we’ll have to see how well it performs on full frame once the lens ships and is out there in the world for people to play with.

One of the interesting things about it, is that it comes with an interchangeable lens mount. Essentially, it’s an M48 thread, and adapters will be available for Nikon F, Canon EF, Pentax K, Sony E and Micro Four Thirds. But the design offers future-proofing for other cameras, like the Nikon Z mount, Canon RF, and Leica L. All it needs is a new adapter.

Focal length: 250mm
Diameter: 51mm
Aperture: f/4.9
Format: Full Frame, APS-C & Micro Four Thirds
Image Circle: 44mm
Mount: Nikon F, Canon EF, Pentax K, Sony E & Micro Four Thirds (interchangeable)
Optics: 4 elements in 3 groups (Petzvcal)
Dimensions: 225 x 80mm
Weight: 1.47kg
It’s an interesting lens, that looks rather good for wildlife as well as astro, given the footage above and the sample photos on the campaign page. I’m curious how well it would work for portraits, although being a manual focus lens, I’m not curious enough to back the project myself.

If you want to, though, you’ll want to hurry. It’s already doubled its funding goal, and only has three days left to go. You can pledge through Kickstarter now for $649 (93% of the final retail cost once the campaign’s over), which includes the lens, Nikon Canon or Sony mount adapter, a soft carry case and their patented Bahtinov Mask. Lenses are expected to start shipping at some point in March.

tommy2 Loc: Fort Worth, Texas

Had a good experience with the company about a dozen years ago during a r&d project. They started out making peripheral components for telescopes and used one of my Ha Solar Telescopes to develop their own version. It took about a year to complete the project and in the end gave me quite a few of their products for my Astrophotography hobby when returning my ‘scope. Their optics were superior to the mid-priced sets I was using at the time which were Canon/Nixon level - theirs were easily Leica level. Their resulting models are easily competitive with any top of the line telescope on the market today.

Architect1776 Loc: In my mind

Interesting, never heard of it.
Here is a photo of the lens.
https://www.diyphotography.net/this-250mm-f-4-9-lens-is-the-worlds-sharpest-and-has-interchangeable-camera-mounts/

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

The Nikon 500 mm 5.6 lens is the sharpest PF lenses made. It is also the only 500 mm 5.6 PF lens.

tommy2 Loc: Fort Worth, Texas

There are two lenses written about above claimed to be "the sharpest". How about a creditable "sharpness" comparison posted here?

Architect1776 Loc: In my mind

Yes but we are discussing the 250mm.
If you want to discuss your Nikon lens start your own thread.

SonyA580 Loc: FL in the winter & MN in the summer

There was an article some time back about lens manufacturers all getting on the "sharpness" bandwagon, at the expense of other things such as color, bokeh etc., etc. Seems "Sharpness" sells lenses but the bottom line is, it's only one part of what makes a great lens.

SonyA580 Loc: FL in the winter & MN in the summer

duplicate post??

Architect1776 Loc: In my mind

I agree.
This is the fault of digital and the ease of pixel peeping on the computer.
Prior to that it took effort to magnify the grain and people looked at the photo as a whole. That is why I found this article interesting.

O2Ra

Dude really, you went there . This person is showing a wording comparison. You seem to be an angry person inside . Comments like this is the reason I quit coming to the Ugly Hedge Hog forum for a while .
As for the lens it seems like a great lens for the money. The build quality from what I can see looks great. Shot on the Panasonic it did have the Panasonic look for sure . And the image seemed very sharp . Has a Sigma prime looking oof area.

Ponz

This one?

https://www.highpointscientific.com/william-optics-cat-51mm-petzval-apo-imaging-refractor-telescope?utm_source=google&utm_medium=cse&utm_term=WYO-A-RC51&gclid=Cj0KCQiA2L7jBRCBARIsAPeAsaO4387iemChBnFohHg1eI34IJN_o_IPYRw5d4O8kGzpZq6vefYKngQaAqXUEALw_wcB

rocar7 Loc: Alton, England

[quote=Architect1776]This is an interesting claim.
Seeing as Hasselblad and Leica the only 250mm lenses I know of, and believe they are not current lenses, outside some view camera lenses. Were there any other 250mm lenses made for 35mm cameras? So the claim below is interesting like saying the fastest 24 wheel bicycle in the world.

There was at least one other, the Minolta 250mm f5.6 mirror lens. I have one from about 1980. Not by any means the sharpest lens, but fun to play with. I put it on my Sony a6500, which has IBIS, so camera shake is pretty much taken care of. This photo was hand-held at 1/60, and taken through double glazing, but shows the very shallow DOF you get with mirror lenses, as well as the weird bokeh.

They are very sought after for some reason, and fetch about £1000 to £1300 on ebay.

(Download)

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

EXCUSE ME.

Architect1776 Loc: In my mind

[quote=rocar7]

You are right I was not thinking of the Mirrors. There also could have been others besides yours.

So the claim of sharpest most likely will hold.

Architect1776 Loc: In my mind

No anger just fatigue of threads being hijacked to brag about an irrelevant lens to the subject.