Thursday, June 18, 2015

Kelda 85mm f1.8 Lens


EOS 5D, Kelda 85mm@f1.8

Have you ever heard of a lens named Kelda? I hadn't. When you "Google" that name, you'll find a lot more girls named Kelda than anything about the Lenses. It seems that this Chinese optics maker does more alomng the lines of ultra-cheap accessory lenses for older style compact cameras than for DSSLR lenses, but they do make this rather peculiar 85mm f1.8 model for Canon EOS mounts. I came across one in the local Classifieds, and, having sold my Jupiter-9, which was not a good idea, I thought that as it was priced at less than half of what you'd pay now for a Jupiter-9, and no adapter is needed, it would be worth a try. So far, all I've done with it is some snap-shots around our Garden.

By the way - this is a completely manual lens with absolutely no electronic communication between it and the camera. The only thing "Canon EF" abut it is the shape of its aluminium mount, which fastens to the camera perfectly.

First off, it appears that Kelda doesn't know much about their own product, as the box says it's made for APS-C Canon Cameras (in other words, a "digital mount" EF-S) Not so. An EF-S lens will only mount on an APS-C, and is not compatible with "EF" full-frame, but this lens will mount on both EF, where it assumes it's nominal 85mm focal length, and EF-S, where it becomes 136mm.
Other peculiarities - it has a manual Aperture ring with click-stops at 1.8, 2.5, 3, 3.5, 4.5, 6, 10 and 22. I've never seen such an abnormal string of F-Stops on any lens - this one's very strange. It can be used between these click-stops however. I should mention that the Aperture Ring is extremely stiff to turn however, to the point that once you set it, you'll probably not want to change it. On the other hand, the manual focus ring is exceptionally smooth and easy to turn, with no wobble, and just the right amount of friction. Combined with the lens' very accurate focus, meaning that when looking through a DSLR optical viewfinder, this lens really gives a good sense of "snapping" into focus, it is a joy to use. In comparison with , say, the Jupiter-9 with an EF Adapter, focus is much more easily seen with this lens, and you can be confident that your focussing effort will be quick, painless and perfect. It's too bad the Aperture Ring isn't as cooperative.

EOS 5D, Kelda 85mm at f10

Speaking of Aperture, this lens has no provision for a stop-down preview of any kind, which means I you set the Aperture for f10, the viewfinder will be darkened accordingly, making it more difficult to see your depth of field, and the shooting information in the Optical Viewfinder display is also darkened to the point that it cannot be seen in bright sunlight at all. In such cases, you can only get your exposure info from the camera's top-deck display, assuming it has one. keep in mind, the Jupiter-9 has the advantage of a third ring- the stop-down ring, which allows you to focus and expose in full brightness, then stop down to your pre-set f-stop value.

Also, the Aperture Ring has no Depth of Field (DOF) scale. You can only guess, which in some cases, is not good enough. In the above shot, I got better focus on the grass in the foreground than I did on my intended subject -the clothes on the line. Not good.

What about using this lens wide open? Again, it's far from being the best. The first picture (above) has the subject at about a Metre away, and although I got a perfect focus on it, the Bokeh (out of focus area) is quite choppy and busy - again not good. However, if you're careful about it, this lens can be quite good wide open. I am very pleased with the following three shots, with subjects all at the lens' minimum focal distance of 0.8m and all at f1.8 -




 With this lens, Bokeh can be quite good if you choose your background carefully. I am also quite pleased with the colour - nice and deep, nice and rich, with quite a bit of fall-off "Vignetting" in the corners, which is not supposed to be good, but I like it... quite often I will add Vignetting in post-processing if the lens doesn't provide enough of it.

I'm also quite sure this lens will make a great night shooter on-the-streets. Also, although I have no good way of testing this, I would say that linear distortion ("barrel and pin-cushion") are very low with this lens - surprisingly so.

So, I'll sum it up with all the typical scores of a lens test:

Build Quality (except Aperture Ring)                                  9/10
Mount - perfectly snug                                                        10/10
Controls - Aperture Ring                                                     0/10 (yes, it's that bad)
Controls - Focus Ring                                                         10/10 (yes it's that good)
Optics - Colour                                                                     9/10
Optics - Vignetting                                                               7/10 (unless you like Vignetting)
Optics - Distortion                                                                9/10
Optics - Sharpness                                                                7/10 (again, depending on what you like)
Optics - Bokeh                                                                      6/10
Usability - hindered by no DOF Scale and no stop-down    5/10
Value for money - new                                                         4/10
Value for money - used                                                         9/10
Accessories included - front/rear caps, hood, pouch            10/10

Conclusion:

I wouldn't buy one of these new - you would be better off with a used Jupiter-9 and mounting adapter. However, second hand, the Kelda 85mm f1.8 should be around US$75, and because of it's great optical performance, even wide open, which is what really counts in the end, and it's superb manual focussing, at second-hand pricing, you can't go wrong. To get the "real-deal" Canon EF 85mm f1.8 is over $500, which is of course an Auto Focus / Auto Exposure lens. Other manual focus lenses, like the Jupiter-9, or a genuine Zeiss, have the disadvantage of requiring an adapter to fit the EOS / EF Mount, which throws your manual focus off a little bit - sometimes enough to ruin your shot. Because the Kelda mates perfectly to both EF and EF-S mounts, and the focus ring is so damn great, it will provide great, hassle free manual focussing, even wide open in the dark - (errr... perhaps I should test this before I say it, but I think it would be a great night lens). If Chinese manufacture has any sense of design, it almost seems as if this lens was actually designed to be used in the dark, wide-open. I can't wait to try it out, and I promise - this will be the subject of my next post.

Thursday, June 4, 2015

Best Way to Digital B&W


Charley - BW
I've always liked B&W, and grew accustomed to Film Emulation software to make a good B&W out of a colour JPG file. Some of the Film Emulation approaches I'd discovered for free are in GIMP (under Colours > BW Film Simulation) and G'Mic within GIMP (Filters > G'Mic > Film emulation > B&W), not to mention DxO Film Pack (not free). DxO Optics Pro, which in my opinion is the best Raw File Conversion software on the market (also not free, but relatively cheap) offers some B&W presets, as do Opensource (free) Programs like Photivo and RawTherape, with built-in control of some parameters.

But I've only come across one Program which has slider control adjustment available for all parameters you could think of within one control screen, with a good size on-screen preview, and that is also built into the G'Mic-within-GIMP Black and White filter. All within one control box, you can adjust Red, Green and Blue Levels and Smoothness, Hue and Saturation, Gamma, Contrast, Brightness, Grain (Shadows, Mid-tones, Highlights, Grain tone fading, Grain scale, Grain type, Local Contrast with Radius and Smoothing, and as if that's not enough, you also get a Psuedo-Grey dithering control. I created the above file from this original:

Charley, from EOS 5D at ISO 1600, EF 50mm @ f1.8, DxO optics pro
I won't name all the specific actions I took in G'Mic to do the B&W conversion, nor will I mention everything I did with the Raw File within DxO-OP - what's important is getting results you're pleased with. Otherwise, this would be a Tutorial!

So, this is NOT FILM Emulation - rather, this is beyond Film Emulation. The emulation approach is great, as you can get results with one-click (or screen tap). This is Black and White Conversion. As far as a specific film type, there's no way of knowing what I've converted to - this is strictly Digital B&W "Digital Darkroom" stuff. If you were shooting a camera with B&W film, and had a home darkroom, you would be adjusting a lot of the above-mentioned parameters via the film you use, coloured lens filters, type of chemicals, temperature and time. This may sound far more interesting to a whole lot of people, but if you're a digital shooter, and if you want full B&W photography control in one place, this is a great computer app to get.

Although I'm not providing a Tutorial here, some things might need a bit of explanation... lets get the weirdest one out of the way first - "Psuedo-Gray Dithering". What this does is provide an expanded range of "colours" to your grey-scale used in the conversion. Normal B&W conversion (as in the "colour desaturation approach" leaves only 256 values from pure white to pure black. Psuedo-grey adds a whole lot more - up to 1786, by borrowing a wee bit of various colours to mix in with the greys. Depending on your computer screen, or your printer, you may, or may not see any difference. Just a note - my computer screen does not allow me to see this effect make any difference, but my printer actually does. I did not use the effect in the above sample. A film camera equivalent to this might be a form of "cross processing' where you introduce some C-41 chemicals, or use one of the B&W films available for C-41 "drug-store" processing. With film however, there is not much you can do to control the range of the effect.

Next, what is "Local Contrast"? Basically, it is an extremely effective way of extracting more sharpness and detail - but beware - this is best done when converting your Raw File output from your camera to a JPG. Here within GIMP / G'Mic, you  don't have that option, because there is really no extra detail to extract from a file that's already JPG. It is only a "Psuedo - Local Contrast", really no better than the well known "Unsharp Mask". I did add a bit of Local Contrast to the original colour conversion (Raw to JPG) you see above, using DxO Optics Pro. I DID NOT use the Local Contrast slider in G'Mic.

Finally, for a Black and White Conversion, why would there be "Hue and Saturation" sliders, along with controls for Red, Green and Blue?

To answer the first one, Hue and Saturation can provide variable contrast in different parts of your picture. This is normally done within Photoshop (or GIMP) by first changing the Hue and Saturation, and then de-saturating (removing all colour) as a second step. Here within the G'Mic Program, you can do this in one step, while viewing a B&W preview - a real time saver. As for Red Green and Blue, this provides a direct correlation to film photography, where a B&W shooter would use these colour (along with yellow and orange) filters on his lens to provide varying differences in contrast - a very common example was to use a yellow filter to enhance the look of clouds in the sky for a B&W filter. Here (and with many other Apps), you have "digital lens filters". By the way, you should never use a real glass lens filter on a digital camera, unless you know what you're doing and really want an unpredictable result. This is because a digital camera sensor already has millions of tiny coloured glass RGB filters built into it, and interaction between these and a lens filter intended for film will not work the way you think it might. Stick with digital filters for digital cameras.

Finally, just a note regarding B&W photography in general - it retains an enormous popularity, as I notice that my B&W uploads to Flickr usually get double the number of Views and Faves in relation to my colour pics. Also, my B&W shots get far more than double anything I try that looks like an Instagram "nostalgia" filter. What does this suggest? Could it be that we all like the TRUE nostalgia of B&W? Is there some sort of a greater purity? (Because no "Nostalgia" Instagram picture ever really looked like that, right?) What about a B&W-only digital camera, for which only Leica has jumped in so far, with their super expensive "M" - why? A new rumour out there in Blog-Land is that Sony is coming out with a B&W camera - to be announced very very soon. Why not? In reality, a Digital B&W sensor is made by NOT including the RGB coloured micro-lenses I mentioned above, with everything else remaining the same. If B&W is more popular, why don't all camera makers provide us with such a device that's actually easier for them to make, and offer it at a proportionally reduced cost? These days, even the most amateur photographer (like me) owns more than one camera - why not having one of those dedicated to B&W? Surely it would help us learn, as good Photographers once had to, how to "see in black and white"? With colour digital cameras, we don't do that now -- it's more like "maybe this picture would look better in B&W" and so we simply run the pic through one of many device apps to give it a try... this IS NOT "seeing in black and white", the way all film shooters once had to.

Is anybody out there listening??