[RioRico]

kenafein is quite right. Manual lenses are great, and often good cheap fun. At the moment I have ~225 lenses. Just 10 of those are autofocus: 9 newer zooms and the FA50/1.4, which was cheaper when I got it 3.4 years ago! Your 28 and 50 are good basic lenses and if you do as Ken suggests, are no problem to use. Here are some focusing methods:

• Catch-In-Focus aka trap-focus aka CIF: With my delaminating eyeballs, I depend on CIF.
• Hyperfocus: Set the M28 to f/11 and focus to 3m; DOF will extend from 1.5m to infinity.
• Zone focus: Set the lens to f/11; set your focus range inside the f/8 marks on the lens.
• Pedestrian focus: Sometimes I just pace-off the distance and set the lens accordingly.

Remember, for stop-down metering+exposure with M-type lenses, you must use the Green button in M mode. And when shooting at slower shutter speeds, SR will save your butt. Sorry, I can't recommend any AF zooms within your budget, except that the 17-50 and 55-300 combination is a good place to start. Cheers!

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Last edited by RioRico; 10-30-2011 at 01:32 PM.

[kenafein]

Lots of thanks Kenafein! I will stay with de zooms than and the primes I already own

I've read something about that Catch in Focus technique. The downside of it was that the SLR could take the picture while you're still focussing, so you get focussing blur. What's your opinion about that? An other thing: the somewhat newer Pentax-A (+-1985) lenses seems to have automated aperture (that's the translation of diaphragm right?). Apart from the focussing, how does the SLR deals with the aperture? Aperture clearly have impact on ISO and shutter speed right? And since the camera gets no info about the aperture setting, how does it deal with that?

With an A lens the camera will control the aperture and therefore, it can control metering and you can use all the various modes on your camera. With M lenses you have to shoot the camera in manual mode. You can use the green button to meter for you and set the shutter speed, but you have to stop down the lens to your intended aperture using the aperture ring on the lens. It's not really much trouble, but if you stop down to say F16 then your viewfinder will get very dark and it will be hard to focus. If your lighting conditions don't change much you really seldom need to repress the green button.

Catch in focus isn't perfect, it does take a bit of practice. You do need a steady hand. One of the problems is the camera may trigger focus before your intended target is in focus. Say you're targeting someone's eyes for a thin DOF shot and it triggers off their nose. Play with it, I think you'll like it. If not, it still gives you a focus confirmation light and you can press the shutter. I think introducing camera shake is all in technique. You can cause a lot of camera shake with an itchy trigger finger too. The camera's anti-shake compensates for some of this. It's kind of like a gun, if you tug rather than squeeze your shot can go real wide. As for focus blur, I'm usually coming in slow when I know I'm close, you can see it, and it chirps. It really hasn't been a problem for me, but maybe for someone who is really fast.

[Tomm]

Damn I can't wait to try it! Thank you both.

But some things are still unclear to me. For example, Ken you say: 'stop down the lens to your intended aperture'. RioRico is talking about the same thing at Hyperfocus en Zone Focus I think? Isn't it as simple as just put the lens in a desired aperture setting, press the green button, focus and shoot?

Were is this needed for: ''Set the M28 to f/11 and focus to 3m; DOF will extend from 1.5m to infinity.''? Isn't is possible to change the f/11 to f/1.7 or an other value, press the green button, focus and shoot? Or is it more complicated? I starting to feel that I'm missing some very basic knowledge here?

[kenafein]

Damn I can't wait to try it! Thank you both.

But some things are still unclear to me. For example, Ken you say: 'stop down the lens to your intended aperture'. RioRico is talking about the same thing at Hyperfocus en Zone Focus I think? Isn't it as simple as just put the lens in a desired aperture setting, press the green button, focus and shoot?

Were is this needed for: ''Set the M28 to f/11 and focus to 3m; DOF will extend from 1.5m to infinity.''? Isn't is possible to change the f/11 to f/1.7 or an other value, press the green button, focus and shoot? Or is it more complicated? I starting to feel that I'm missing some very basic knowledge here?

RioRico was telling you how to set the hyperfocal length for your 28mm lens. If you set it up like he said, then you can basically use it as a point and shoot camera, no need to focus on anything that is at least 1.5 meters ahead of you. It is a way of making sure you have enough Depth of Field not to have to worry about focus. Frame your shot and pull the trigger.

Of course you can set the f stop to any desired number, but then you have to focus.

Read this link Digital Photography Tutorials it will help explain all the basics. It's really helpful.

[Tomm]

Nice I get it. I'll read that tutorial to get the precise in and outs. A very handy tip indeed

Thank you many times!

@ RioRico: What do you think of the kit lens with 28-75mm f2.8? With the primes I already own?

@ Ken: The 28-75mm is optical quite similar to the 17-50mm f2.8 or not?

[RioRico]

No, it's actually much simpler. Hyperfocus is a subset of Zone Focus, where the DOF zone extends to infinity. DOF is the distance from the lens where images seem to be in acceptable focus.

The point of Zone Focus (and Hyperfocus) is that you don't need to focus exactly on a subject. Everything within the zone looks acceptably sharp. You can use the camera as a point-and-shoot. So if I hyperfocus a manual lens, I just need to know where the near edge of the range is. In the example I gave above, everything from 1.5m to infinity looks sharp. This is exactly how old box cameras worked!

If you want thin DOF, such as to isolate a subject from their context, then use a wide aperture like f/1.7, and focus on the subject until you get the Focus Confirmation light, or until CIF trips the shutter. If you want pictures where everything is acceptably sharp, use Hyperfocus. If you want to control the DOF so that just a certain range of distances are sharp, use Zone Focus.

Using any of those focusing techniques on M-type lenses, you still must use the Green button in Manual mode, to stop down the lens for metering and exposure. Or you can be in any Auto mode; the aperture will remain wide-open, and DOF will be at its thinnest.

I hope this explanation helps. If not, ask again!

[RioRico]

@ RioRico: What do you think of the kit lens with 28-75mm f2.8? With the primes I already own?

I'm sorry, I don't know that zoom. I avoid the Which-Kit-Replacement-Is-Best wars.

Both manual primes are excellent, no matter what zooms you have. They are both lightweight, and fine optical performers. I have and use both. The M50 will deliver images that no zoom can match. The M28 is a great 'normal' lens on an APS-C camera, and it handles Zone Focus very well.

I haven't time right now -- I've been told to go outside and perform some yardwork -- but later I'll talk about choosing lenses. Stay tuned!

[kenafein]

I don't know about anything the optical formula of the 17-50, but it is a lens designed for APS-C cameras and the 28-75 is designed for full frame/film. The 17-50 on APS-C covers approximately the same range as the 28-75 does on film/full frame. They are both very useful focal lengths I think. Some people consider the 28-75 to be awkward (I am not one of them).

A good zoom setup for you might be the DA12-24mm, the Tamron 28-75, and the DA55-300. Along with your 50/1.7 that's a pretty solid kit, good enough for just about everything. Covering you from 12-300 with low light capabilities and a pseudo macro ability. I think it would end up costing you about $1200 when all is said and done. You could save $200 getting the tamron 10-24 and gain 2mm on the wide end to boot.

or 17-50 + DA55-300 for $600 + a raynox macro adapter for your DA($75).

Sprinkle liberally with cheap manual focus primes for fun . Your collection can be built over time, as long as you don't contract the deadly LBA(Lens buying addiction).

[RioRico]

OK, I'm back. Brace yourself.

My initial kit for my K20D, bought just a month before Hoya bought Pentax some 3.4 years ago, were the DA10-17, DA18-250, and FA50/1.4. I wanted fisheye, superzoom, and a Fast Fifty. Now I supplement the fisheye with the Tamron 10-24 ultrawide, and that's my minimal AF kit. And I've filled in with many (fairly) inexpensive fast manual primes: 24-28-35-58-85mm f/2, 135/2.5, etc. And with many specialty lenses -- although the DA18-250 is my basic lens, and all the rest are specialty items.

So, an approach to accumulating lenses:

1) Coverage. My Tamron 10-24 and DA18-250 and Sigma 170-500 cover just about everything.
2) Speed: The Fast Fifties (including 50/1.2 and 55/1.4) and those f/2's are good for extremes.
3) Character/Specialties: Fisheyes; macros; presets (many iris blades); glass for period effects.
4) Weirdness: I gather whatever optical materials can be stuffed into a bellows or other mount.

In a nutshell: Figure out what focal length range(s) you want to cover. It's good to have modern AF zooms for this. Then decide which focal lengths deserve special attention, for speed or exceptional IQ. Then think about any special needs, like macro and fisheye shooting. Then grab as much strange glass as possible, because it's really fun!

Some of my favorites are cheap tiny slow many-bladed old presets that give a very clear sharp 1950's German rendering to images. I also love cheap enlarger lenses with edge-to-edge flatfield sharpness, mounted on bellows and/or tubes. For more on this, see https://www.pentaxforums.com/forums/pentax-lens-articles/152336-cheap-macro-b...lose-work.html. Old projection lenses on bellows, used with the right filter, can give a very 1870's look to images. Fun stuff.

But I digress. A good starting kit with a new dSLR is the kit pair of DA18-55WR and DA55-300, mostly because they're a bargain. I don't like or use that pair together for myself because I shoot a lot between 35-70mm and swapping lenses around 55mm is a pain. That's why I like the DA18-250. It and its Tamron twin are no longer produced but are widely available used. For that most-used range, I shoot an old F35-70 that cost me all of US$11. It's agile, sharp as a bag of primes, small, and should be found for well under US$50.

But if you don't think you'll want longer focal lengths right away, forget all that. kenafein's suggestions above sound just about right. Or maybe they're too expensive. Oh bother. Then if you don't need reach, just get the K5 body and the Tamron 17-50/2.8. Accumulate more lenses later. Good luck!

[Tomm]

Whoo, that's a lot of information!

RioRico, your explanation of these zoom techniques is very clear! Awesome, without having the body yet there are hundreds of things I would like to try! You're saying you're shooting a lot between 35-70mm, with the crop sensor of the K5 body this will equals roughly a 18-55mm lens then or not? I know you don't know the 28-75mm/f2.8, but what do you think about that range for an all round lens taking into account that it will be used with a crop sensor? Is it wide enough? Nice article by the way!

At the moment I think I will buy the 28-75mm with the kit lens at first. The only thing I have some doubts about is the wide angle of the 28-75mm on a crop sensor body? After that I will probably have the LBA virus! The longer zoom range will follow short after I know what range is important for me.

[RioRico]

Whoo, that's a lot of information!

I try not to make it too dense, but there it is.

RioRico, your explanation of these zoom techniques is very clear! Awesome, without having the body yet there are hundreds of things I would like to try! You're saying you're shooting a lot between 35-70mm, with the crop sensor of the K5 body this will equals roughly a 18-55mm lens then or not? I know you don't know the 28-75mm/f2.8, but what do you think about that range for an all round lens taking into account that it will be used with a crop sensor? Is it wide enough? Nice article by the way!

The F35-70 on APS-C has a FOV range similar to 50-100mm on 135/FF. It's a people-and-places lens, not a general purpose lens -- it's good for portraits with distant backgrounds. Really, 18-55 or 17-70 or 16-45 are much better for general purpose shooting -- that's why 18-55 is the kit lens on APS-C, just as 28-80 was for 135/FF cameras. If you look at collections of published 'scapes, you'll see that they're mostly shot in the range equivalent to 18-55mm. I do have some zooms around 28-80mm, but they're for special purposes, not for general work .

It really is handy to have lenses wider than 28mm, which is just 'normal' on APS-C. 28-80mm in 135/FF is FOV-like 43-120mm on APS-C, a good portrait range, from 3/4 body to tight headshots. An 18-55mm on APS-C takes you from fairly wide (for grabbing contexts) to fairly long (for 1/2-body shots). This is just a very useful range.

At the moment I think I will buy the 28-75mm with the kit lens at first. The only thing I have some doubts about is the wide angle of the 28-75mm on a crop sensor body? After that I will probably have the LBA virus! The longer zoom range will follow short after I know what range is important for me.

Again: 28mm isn't wide on APS-C. The DA18-55 is the least expensive widest lens available. Its replacements from 16-45 to 17-70 are a bit sharper and faster and rather more costly. I really don't think that a 28-75 is a good lens to start with, not unless you have a 10-24 also.

[Tomm]

Thanks Rico, I also have the kit lens with it to cover the 17-28mm range. I'm looking at different pictures with focal range info to see what suits me best.

All of a sudden a bumped into the Sigma 24-70mm F2.8 EX DG Macro and it is 4 mm wider. Not much but still.. What about that one? I can buy it for 500 dollars..

[kenafein]

Here is a link to the review of the sigma on this site.

Sigma 24-70mm F2.8 EX DG Macro Lens Reviews - Sigma Lenses - Pentax Lens Review Database

and the Tamron

Tamron 28-75mm F2.8 AF XR Di LD Macro SP Lens Reviews - Tamron Lenses - Pentax Lens Review Database

You'll have to decide which works for you. 24-70 is a bit more useful, but I think the lens is also bigger and heavier.

[Tomm]

Here is a link to the review of the sigma on this site.

Sigma 24-70mm F2.8 EX DG Macro Lens Reviews - Sigma Lenses - Pentax Lens Review Database

and the Tamron

Tamron 28-75mm F2.8 AF XR Di LD Macro SP Lens Reviews - Tamron Lenses - Pentax Lens Review Database

You'll have to decide which works for you. 24-70 is a bit more useful, but I think the lens is also bigger and heavier.

You're right again. Read a lot of threads and seems like the Tammy is slightly sharper but has a worse build quality. For de 200 dollars extra and the weight of the Sigma I can better go for the Sigma.

[kenyee]

All of a sudden a bumped into the Sigma 24-70mm F2.8 EX DG Macro and it is 4 mm wider. Not much but still.. What about that one? I can buy it for 500 dollars..

This is weaker in flare performance and sharpness than the Tamron...and the latest Sigma 24-70 OS...
But it is less expensive for that reason...