Tag Archives: Canon

Meike announces 6-11mm fisheye for APS-C

1 Oct

The f/3.5 lens is reported to give a 180 degree maximum field of view. However, it is not stated whether this is true for Nikon or Canon – since they use different crop factors, they can’t have the same field of view with the same lens without further modification.

Screen Shot 2018-10-01 at 21.10.30

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Lens equivalence

23 Sep

On the eve (almost) of Canon launching its 32mm f/1.4 lens for EF-M mount (i.e. 1.6 crop factor APS-C), let me point out that in terms of field of view and achievable shallow depth of field, this is roughly the same as a 50mm f/2 on full frame.

I thought it would be useful to write a brief reference for folks to refer to when comparing lenses with different imaging circles (e.g. full frame vs. APS-C), giving specific values for popular focal lengths and apertures.

So in this vein, a 35/0.95 APS-C lens (e.g. Mitakon) is roughly like a 50/1.4 on full frame, and a 50/1.1 for APS-C (e.g. Kamlan) is similar to 85/2 on full frame. So the sometimes affordable 85/1.8 lenses for full frame cameras don’t get you into much better territory than 50/1.2 on APS-C, although you may by this route obtain autofocus at a similar price but at the additional cost of needing a full frame body.

Also note that light equivalence is already taken into account – there’s almost a stop difference between f/1.8 and f/1.2, with a little bit of wiggle room for manufacturer’s specs (aka cheating).

Once upon a time, it used to be true that digital sensors could not work at shallow depth of field very well as the angle at which light would typically fall onto the sensor was typically shallow as well and many of these shallow rays would be deflected off the surface of the sensor, avoiding detection. So on the assumption that that’s still true of modern sensors, working with an f/2 lens on full frame would be preferable to working with f/1.4 on APS-C. One might assume that sensor design has markedly improved in this aspect since mirrorless cameras have to cope with even shallower angles – however, note that mirrorless lenses are typically a little narrower at the aperture and recent lens designs have been very long and heavy, giving an overall less acute angle of incidence, which might be a hint as to the remaining challenges in this area.

If sharpness is what we care about, a full frame camera is generally preferable as the format allows for greater manufacturing tolerances in lenses, and the same lens will, generally speaking, give a sharper image on full frame than APS-C, depending on the sharpness fall-off towards the corners.

And one more thing – if we compare the front element sizes of, say, a 32/1.4 (22.9mm) and 50/2 (25mm), we don’t see a lot of difference, so we might suspect that in terms of the torque needed for autofocus to move elements inside such lenses, there may not be a lot to be lost or gained. So there may not be any particularly convincing excuse for a 35/0.95 lens to not have autofocus, unless we take into account the generally smaller build and smaller battery of a typical APS-C camera compared to a full frame model.

But getting back to the equivalence issue, it’s fair to conclude that most “fast” lenses for APS-C sensors offer nothing particularly revolutionary, this being even more true if they have to be focused manually.

Sony 24mm/1.4 – compact and reasonably priced

21 Sep

Sony has announced its 24mm f/1.4 GM (Gold Master) lens, and, once the shorter focal flange distance of the system is taken into account, it’s quite a compact lens compared to those on competing systems, or by competing manufacturers:

24by1.4compared3

To my mind, lenses with short focal lenses should also be short in build, so that when you squeeze into a corner, you can get the shot, and Sony looks to be the best current choice there:

24mmLensesOnCameras

From left to right: Sony A7 III with 24/1.4, Canon 6D II with 24/1.4 II, Nikon D610 with 24/1.4 and Sigma SD Quattro H (crop factor 1.3) with 24/1.4. Usual caveats about finger space apply.

Sony vs. Nikon vs. Canon full frame mirrorless

17 Sep

Here’s a comparison of the existing full frame mirrorless cameras from Sony with the newly announced Nikon and Canon efforts.

Graphic comparing features of mirrorless cameras by Sony, Nikon and Canon

Should you wait for the Panasonic full frame? (UPDATED!)

14 Sep

This is a comparison of the recent Nikon and Canon mirrorless full frame releases to the rumoured Panasonic full frame specs. If anyone’s feeling the cash a little loose in their pocket but mindful of missing out on a potentially superior camera being released in the near future, I hope this can help you some. In the cheat-sheet below, I’ve dubbed the Panasonic full frame camera the Panasonic FF – this will likely not be its actual name. Information comes from several sources, including 43rumors.com, thenewcamera.com and Cameraegg.

Updated graphic (resolution is now given as “more than 42 megapixels” by sources and lens as L-mount, which allows available lenses to be calculated (has been added); Sony cameras have been added for additional comparison):

ff_mirrorless_compared004

Old version:

ff_mirrorless_compared002

Yongnuo 85/1.8 with better bokeh, less CA and noisier AF than Canon

12 Feb

For full details, see the video by Christopher Frost, below:

 

The breakfastographer’s opinion based on the samples shown is that the bokeh is nicer and the CA much lower in the Yongnuo. Corner sharpness is worse, though, and the autofocus has various issues described in the video. No statement was made about focus throw, but it seems to be okay, so manually focusing is an option. At a price of half the Canon, it’s cheaper than a Samyang/Rokinon/Bower/etc., which would also provide only manual focus.

In spite of the corner softness, it’s sold as a full frame lens, and its value proposition as a portrait lens is hard to beat on that format. If you do want to go cheaper, there are 50/1.8 options for APS-C cameras for just over a 100 eurodollars, but bokeh will be better with the 85/full frame combination – or really 85 on any format!

Sigma brings back the moiré

3 Feb

I believe I’ve written on this subject before. DPReview just exclusively announced the results of DxOMark testing of the Sigma 85mm f/1.4 “Art” lens, announcing it to have achieved a perfect 36 “perceptual megapixels” on the Nikon D810’s 36 megapixel sensor. It therefore sort-of-ties with the Sony FE 90mm f/2.8 macro lens, which achieved 42 perceptual megapixels on a 42 megapixel sensor.

Discussion immediately broke out on whether the Zeiss Otus 85/1.4 or Nikon 105/1.4 provided nicer bokeh and whether this was, in fact, more important than sharpness. The Zeiss, in particular, is almost tied with the Sigma for sharpness, and like it excels in many other technically measurable characteristics. The Nikon may be half a step behind, and in fact has a focal length of 94.8mm vs. the Sigma’s 79.9mm, so is more comparable than it sounds at first.

But back to my original point, which is the following:

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Excerpt from DPReview sample image no. 30, of the Sigma 85mm samples.

That’s right, moiré. It is a physical certainty that if the sensor has no anti-aliasing filter on it, and the lens outresolves the sensor, you will see moiré on certain subjects (you can find technical details of moiré and aliasing on the Wikipedia pages, moiré pattern and Nyquist frequency). Many manufacturers have dropped the anti-aliasing filter to squeeze more resolution out of their images and as a small cost-saving, or installed a second filter that cancels the first (slight cost increase). Wisely, Canon added the 5Ds without the R to their line-up, which cuts back on moiré much better than the 5Ds R.

In Nikonland, it seems the highest resolving lenses and highest resolving sensors do not make a good pair. That being so, should we buy high resolution cameras at all, and what other choices do we have? Both the Nikon D600 and D610 have weak AA filters (link in Polish) – a bad idea for a lower-resovling camera as the range of lenses that outresolve it will be greater.

Pentax now releases its cameras with an AA filter that works up to shutter speeds of 1/1000s – presumably adequate for most portrait work, and hopeful that anything you’ll want to shoot above that shutter speed will be moving so fast that aliasing is not likely.

In spite of this, Pentax remains, as of this writing, a stalwart of compact lenses that value bokeh over resolution – partly, perhaps, owing to the fact that some of its lenses have been available for quite some time.

It’s well known that Tamron and Pentax have been sitting in a tree lately, and so it is fitting that Tamron somewhat recently launched a line of f/1.8 primes – more compact than the competition’s f/1.4 standard. DxOMark allows comparing Tamron’s 85mm lens with Zeiss’ Otus and Milvus, for instance, and there’s hardly a hair between them. Most surprising perhaps is the performance of the Milvus at less than half the price of the Otus.

Incidentally, while the three aforementioned lenses max out the D800E’s sensor at 36 perceptual megapixels, Sony’s new Gold Master 85mm lens reaches no more than the same value – 36 P-Mpix on an AA-filterless 42 megapixel sensor.

It’s worth asking therefore whether the trend for the second half of this decade is going to continue with lenses increasing in size, resolving power, and price, as exemplified by the Art and Otus, or a reconsideration of traditional values.* If the former, I hope consumers will be asking for strong anti-aliasing filters, and that camera makers, in spite of mobile phone cameras nipping at their heels, will grant that gift.

*An opportunity, perhaps, for Chinese lens makers trying to push into the market.

Update 7 February 2017: For differences between the Art and Otus, check out Roger Cicala’s blog post.