Sigma has just announced two new lenses.
One is the new upgrade to the discontinued, but much loved 70mm Macro. It will be the new 70mm F2.8 DG Macro ART lens.
The other is a much anticipated 105mm F1.4 DG ART Lens. This thing is a BEAST and will come with its own tripod collar included. A 105mm needing a tripod collar? Anyone familiar with Sigmas 85mm F1.4 DG ART Lens will easily understand the need for it!
Official announcements and specs to be released at the CP+ Show in Japan later next week.

I wrote an email to Sophie Triantaphillidou, who is one of the authors of The Manual of Photography, a mathamatics-based book on all things photography that I refer to often. Sophie T. is a principal lecturer and director of the Imaging Technology Research Group at the University of Westminister. She has received numerous awards in her field and has a PhD in imaging science, just to name a very few of her accomplishments. So, read on about RAW and JPEG and take what you can from someone who actually knows what she is talking about, a true expert in the field. Everything below is from her two emails to me. A very nice lady.

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Thank you for the recommendation. It is interesting to know that there are debates amongst photographers going on regarding RAW vs JPEG.

In the manual the RAW and JPEG/JPEG2000 file formats are summarized in chapter 17. In chapter 25, workflows, there is again a mention to file formats for different workflows.

If I were to summarise:
- RAW is a ‘native’ file format that the camera can provide. Its exact specification depends on the camera manufacturer, it cannot be visualized unless it is ‘rendered’ by a RAW convertor, since it is a one-channel image (a mosaic image). When it is rendered by the RAW convertor (where you get to see it), it has usually been processed using a basic workflow: 1) de-mosaic to make 3-channels (RGB), 2( de-noise (to remove some basic sensor noise), 3) sharpened (to enhance edges that the de-noising operation has blurred). RAW has high bit-depth (often 16 bits per channel), meaning that there is much more room for tonal manipulation. Pixel values are normally linear with luminance (tone is ‘unrendered'), although the RAW convertors may implement a gamma correction (4th step on the workflow) that allows good tonal rendering on common displays. RAW files require a lot of space (both because of bit-depth and no compression) but leave room for fine manipulation/optimisation after shooting. Depending on shooting conditions (if they are no optimal) RAW images can look bad on common displays. But they have much more potential than JPEGs to be fixed!

- JPEG has received all 3 basic processing steps that I list above, plus gamma correction (tone optimisation for displays), plus lossy compression (reduction of information, in order to reduce file size). It is usually 8-bit-depth (it can be more), meaning that there is not as much room for tonal manipulation. Depending on the amount of compression, you may see artifacts associated with JPEG. So JPEG is a less ‘valuable’ image file, with less info. BUT, it can be rendered directly on displays, it is optimised for display viewing, and is small in file-size comparatively.

So depending on the use of the image and expertise to optimise it, once chooses accordingly.

I hope this helps!
Sophie

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If you re-save a JPEG it will re-compress (which degrades the file). If you open and close without re-saving you do not change it.

That’s it for now!
Sophie

Nikon makes a 24-120mm "FX" (full frame capable). Canon doesn't.

And... Canon doesn't make an "EF" (full frame capable) 28-200mm.

Canon DOES make an EF 28-300mm f/3.5-5.6L IS USM... That's a fine, high performance L-series lens, but rather pricey, big and heavy: $2449, 3.67 lb., 77mm filters, and nearly twice the length of the 18-135s. It comes with a tripod mounting collar, too (removable).

Compare to the EF-S 18-135mm f/3.5-5.6 IS (three versions: older micro motor, newer STM and latest "Nano" USM), which sell for $350-$600, weigh just over 1 lb. and use 67mm filters.

There are three versions of Canon EF 24-105mm: original f/4L IS USM (not discontinued, but widely avail.), a cheaper f/3.5-5.6 non-L STM, and an f/4L IS "II" Nano USM. Those sell for $1000, $600 and $1100, respectively. They weigh between 1 lb 3 oz and 1 lb. 12 oz and all use a 77mm filter.

Quite frankly, none of the Canon 24-105s have impressed me all that much. Until recently Canon has offered an EF 28-135mm f/3.5-5.6 IS USM. It dates back to the film days, but actually holds it's own quite well against the 24-105s in terms of image quality and performance. It just doesn't seem as well built or sealed as the L-series (though it's actually proved to be just about as durable as the original)... BUT often sells for far less: around $200 used, or around $450 new before it was discontinued. Over the years, I've used four or five different copies of the EF 28-135mm and found them quite good. Never felt the need to spend more for a 24-105 that gave similar performance.

I have also used the much more expensive, larger and heavier EF 24-70mm f/2.8 USM (not stabilized, even the "II"). It's almost embarrassing, how close the 28-135mm is in terms of image quality... but sometimes I just need f/2.8!

If I were shopping today, for a top quality walk-around/standard zoom I'd probably buy the Canon EF 24-70mm f/4L IS USM. For about $1000 it's got nearly as good image quality as the 2X as expensive, heavier, bigger EF 24-70mm f/2.8L II (which is considered the best of all in terms of IQ alone)... Except the f/4L lens has IS (the f/2.8 doesn't) AND the f/4L can focus to an amazing .70X all on it's own (possibly making a separate macro lens unnecessary... for comparison the best the f/2.8L II can do by itself is .21X).

I'd probably usually pair that up with my EF 100-400L II (w/1.4X teleconverter, if using on full frame).... and possibly a 16-35mm f/4 IS USM... for a reasonable size & weight "hiking" kit. When I didn't need the "reach" of the 400mm, I'd substitute EF 70-200mm f/4L IS USM.

Canon has also made a bunch of different EF 28-90mm and 28-105mm over the years. I haven't used any of them, so can't comment.

Why do you think you need full frame? Just gotta ask, because there are a lot of "myths" about it. Unless you plan to make really big prints (upwards of 16x24"), or crop your images heavily (or both), you aren't likely to see a whole lot of difference from a recent, high quality APS-C model. For example, Canon 6D Mark II is 26MP... or for half the money an APS-C 80D is 24MP. Sure the full frame camera is a little better in low light conditions, and can give you a little more control over depth of field... but in some respects an APS-C camera is more versatile. In particular, there's a greater choice of lenses for use on an APS-C camera and the lenses you choose for it can be a lot smaller and lighter weight.