|
Forum: Pentax SLR Lens Discussion
08-29-2011, 07:07 AM
|
| |
I'll distinguish here between lenses for 'miniature' formats (135/FF and crop) and for sub-mini formats (P&S digicams, 8mm cine, CCTV, etc) because the sizes are vastly different.
FF and crop-sensor cams just aren't going to see pancake zooms nor superfast zooms. I have examples of each for sub-mini cameras: a tiny internal zoom in a P&S; the 15-25/1.2 zoom for an 8mm cine cam, fast but long. With our dSLRs and MILC/EVIL cams, we don't have zooms faster than f/2.8 (f/2.6 was the fastest ever made IIRC) nor smaller than the F35-70. We may debate other trade-offs; but if we want speed and/or compactness, we need prime lenses.
An argument against the need for fast primes is that as usable ISO rises, their light-grabbing power just isn't needed. A counter-argument: thin DOF needs a wide aperture. A response: thin DOF can be simulated in PP. That may be anathema to many. Compactness is still a factor: I doubt I'll ever see a 100mm zoom as tiny as the Enna Tele-Sandmar 100/4.5 that's half the size of a SuperTak 55/2, just 35mm wide and extending 40mm from the body. Oh, had I a Kr to mount it on...
Due to physical+optical+economic constraints, zooms just won't supplant primes in the foreseeable future. I think that's a safe prediction, eh?
|
|
Forum: Pentax SLR Lens Discussion
08-19-2011, 09:08 AM
|
| |
Indeed. Different tools for different fools, er I mean purposes. In my bag now: some zooms to cover many possibilities; some primes for more specific uses; a small bellows and a couple of enlarger lenses for getting real close. YMMV.
|
|
Forum: Pentax SLR Lens Discussion
07-15-2011, 09:59 AM
|
| |
I came to Pentax specifically because of the DA10-17, and I do use it throughout its range. It is just so much fun to play with angles and contexts! I also use a Kenko 180 degree fisheye adapter on a zoom lens. At 40mm it is full-circle, at 60mm it is frame-filling, and above 60mm it shows various possible projections. Wide is just NOT ENOUGH!!
The design of a variable-focal-length lens goes 'WAY back, like to around 1890. Look at figure 3 here. I have some Eastman 100-150mm slide-projector lenses that seem to be built like this.
Will humans still be reading in 15 years? ;)
You want a 12mm prime? I have one! It is branded as Vemar but is may be given many different names. Yes, a 12mm fisheye with f/8-11-16 Waterhouse stops, a full-circle lens hood, and lousy optics. No, you *do* need a 12-24, or a 10-20 or 10-24. Some primes suck.
|
|
Forum: Pentax SLR Lens Discussion
07-15-2011, 12:16 AM
|
| |
And so primes and zooms each promote different approaches to photography, as do all the many types of cameras. Each are different tools for different work. None is completely generally THE BEST. At times I definitely want/need a 6x9cm folder, not the K20D. In some places I rely on an old 50/2.8 MFL, not a newer AFL zoom that covers 50mm. Dynamic situations call for a zoom; I work with primes at a different pace.
And note that many use a zoom only or primarily at its extremes. A 'prime' example of this is the DA10-17, which reportedly gets used mostly at 10 OR 17 but not much in between. That's not much different that the odd Soligor C/D DualFocal 85+135mm lens I once had. Or when walking down a populated street, my DA18-250 spends much time locked at 18mm for from-the-hip shots. It might only be extended when I stop to grab faces or shapes. So it's truly a VERY versatile and convenient zoom, while still mostly being used as a wide prime.
|
|
Forum: Pentax SLR Lens Discussion
07-13-2011, 08:59 AM
|
| |
Indeed. With a camera zoom I can look at something, frame it, and shoot. With a prime I must move around to get the right framing. NOTE: I specified "camera zoom" because my Schneider Betavaron 50/125 enlarger zoom, on 32mm extension for non-macro shooting, also requires a great deal of dancing around to get the framing right. If I ever get a 30-70mm focusing helicoid, the Betavaron will become less exacting. Anyway, my oversimplification is that we use AF zooms to TAKE pictures and MF primes to MAKE pictures. I may have mentioned that before. ;)
In a nearby thread asking suggestions for a compact travel kit, I cited ultra-minimalism: Kx+35/2.5, pretty equivalent to the 135 fixed-lens cam with 50/3.5 lens that I used long ago. Step close and it's a short tele; step back and it's just wide enough. Or on some K20D excursions I'll stick with a 28/2. Any of these (or any other fixed lens) forces me to look more closely, see more possibilities, etc. A zoom doesn't *force* laziness, but *allows* us to devote less effort to picture-making.
I'll again mention another favorite option: Enlarger lenses on bellows. These give me a great feeling of freedom. With the right focal length and extension, I can focus from beyond infinity to within very few inches, with a fine degree of control. My little Novoflex Noflexar 100/3.5 on my little Bellowscope just *feels* like a special general-purpose lens. Wide, not in AOV, but in focus range. And at just a few bucks each, it's easy to build a varied yet compact kit. 50mm for close macro; 75mm for portraits; 90-140mm for ... almost everything; 160-200mm to really stretch. And it's odd-looking enough that bystanders notice the rig, not what I'm aiming it at.
|
|
Forum: Pentax SLR Lens Discussion
03-02-2011, 07:39 AM
|
| |
And contrast can be tweaked in PP. And image impact is affected by presentation, how the image is shown. Thus within certain ranges, IQ of zooms and primes may be indistinguishable. So the difference is elsewhere: maximum aperture and thus thinness of DOF; what we can mystically call 'rendering' and 'character' (my fave); and mostly, the different discipline invoked by not being able to zoom optically.
And yes, size matters. My 18-250 or 70-210 or 100-300 zooms each have a certain physical presence at 100mm, protruding about 150mm / 6 inches from the camera body (without hoods). My little Enna Tele-Sandmar 100/4.5 sticks out just 33mm / 1.25 inches. The slow old Enna just doesn't LOOK like an intruding tele, being about half the size of a little F35-70. Rather better for street-shooting than one of those bigger guns. The newer zooms have better IQ than the Enna, but the Enna lets me get people shots where the big guys would be too intimidating. That's the same reason I'll use my little Sakar 500/8 mirror rather than a long 400mm or the Lil'Bigma 170-500, because it doesn't look like a grenade launcher.
To tally-up: Modern zooms have flexibility, decent quality, decent speed, higher prices usually, and are more prone to physical-optical problems. Primes are often smaller, faster, cheaper, sturdier, less obtrusive, more distinctive in character, and one gets more exercise using them. And should I mention longer enlarger lenses on bellows? VERY sharp and cheap and small, and they all do macro! Yada yada...
|
|
Forum: Pentax SLR Lens Discussion
02-28-2011, 01:31 AM
|
| |
And that's at the heart of these photographic explorations: finding what works for each of us. If we all had the same needs-desires-tastes then we'd all be using the very same glass and we wouldn't bother with these forums. Adam would go out of business and would need to find an honest job. Shipping services and eBay would lose a large chunk of their business. I would have to go back to conspiracy / UFO discussions. Oh, the horror! :( No, let us keep disagreeing about glass and stuff, and discovering more possibilities.
|
|
Forum: Pentax SLR Lens Discussion
02-27-2011, 08:30 PM
|
| |
Spoken like an artist and someone who appreciates the subtleties in life.[/QUOTE]
I try.
[/me looks humble]
But for example: I have a few lenses around 35mm, far fewer than 28's and 50's. Various Vivitar and Porst 35/2.8's by Tokina are rather plain-vanilla, capable of accurately rendering pretty much what's before the eye, as is the Mir-1 37/2.8. The F35-70 at 35/3.5 is similar. The Nikkor-O 35/2 has been a photojournalist's standard for decades; the SuperTak 35/3.5 has been a 'scaper's lens for just as long. Both are inhumanly crisp. The Isco Westron 35/2.8 (13 iris blades) seems to have been sprinkled with pixie dust. The Enna Sandmar and Meyer Primagon 35/4.5's (both with 10 iris blades) are slower but quite different, the Enna being funky and the Meyer being classy.
Average (mean) price of those lenses: US$20 each. And I wouldn't give up any of them, except maybe the Viv's. (Enlarger lenses are not included in this accounting.) How much is that 35/1.4 again? Yeah, if I: 1) needed the speed and 2) had the money, I'd get that fast booger. But I'm OK for now.
[/me imagines perfect pictures -- hallucinating again, eh?]
|
|
Forum: Pentax SLR Lens Discussion
02-27-2011, 11:36 AM
|
| |
Each lens is its own "window on the world" and those windows determine how you see what's around you. I prefer my 18-250 to a 18-55 + 55-300 pair because it's a larger window. I value my fast 16-24-28-35-50-58-85-100-135-200 manual primes because each has its own distinct window. I value my slow 21-35-40-50-100-127-135-180-200 primes because each has its own unique qualities, especially preset lenses with many iris blades.
Each lens makes me look at the world in its own way. So I use my few newer AF zooms to TAKE pictures, and my many old manual primes to MAKE pictures. These are quite different approaches. Zooms and primes can each do things the other can't, just like the different abilities of film and digital sensors. And using enlarger lenses on bellows gives even more viewpoints, more possibilities.
There's more to optics than just coverage and IQ. Yes, I could 'cover' a vast range with just 3 zooms: T20-24, DA18-250, S170-500. But they just don't deliver the qualities of superb and/or idiosyncratic primes. That's why many of us prize those bits of old weird glass. Just arrived yesterday: Isco-Gottingen Westar 100/4.5 in Exakta mount, 10 iris blades, ten bucks plus shipping. Slow aperture; smooth, long-throw focus; crisp wide open, rich tonal rendition, zero fringing, a real delight.
Then there's cost. Average (mean) cost of my AF lenses: US$327. Mean cost of my MF lenses: US$20. This matters to me. But hay, it's only money, right?
|
