Function of P-A-AS in Pentax Power Zoom lenses

I can't find any manuals for these power zoom lenses - but i was wondering how

to use the P-A-AS modes, I use it on a K10D.

Thank for any help.

I have a PZ-1p film body, which was designed to make use of all power zoom functions. I do not have the K10D yet.

I can tell you how it all works on my camera, but to check first I must ask- If you just switch your PZ lens to "power zoom" will the power zooming function actually work on the K10D? That is the first thing to determine.

The power zoom lens does function with the K10D. Just push/pull the ring beside the zoom scale.

I was asking about the P-A-AS button on the lens itself. What are these for?

Normally, you would keep the lens seting on "P" and use it just as you described. With the ZX/MZ 5n and MZ-S film SLR cameras, that is the extent of it. The other automatic zoom functions are not available.

But with the PZ/Z-1, 1p all functions are usable, including 3 auto functions. Perhaps with some of the other PZ/Z models as well.

First you push the lens slider switch up to AS, and one of the 3 synbols for these modes should be displayed on the camera LCD panel, and one of the dials can be used to select between the 3 modes. Do this with your K10D and see if you get such a symbol displayed on the LCD. If so, you can proceed, if not, the K10D does not support these functions.

Once you select an auto function, you leave the lens at the "A" setting to operate. To return to regular power zoom, switch back to "p".

These are: (1)zoom clip mode- where a focal length is memorized in camera and can be returned at a push of the button on the side of the lens. (2) Image-size tracking mode- where you can power-zoom to an image size that you wish to frame your subject, push the lens button to memorize your choice, and when your subject moves around, by pushing down on the shutter release button, the lens zooms itself to keep the subject's image size the same. (3) Auto zoom during exposure- to produce special effects of blur around the subject.

The one I have found useful is image-size tracking, for telephoto shots of some sports and wildlife action.

You can find detailed instructions by downloading the PZ-1p manual from pentaximaging.com, click on costomer support.

I would like to know what you find about the K10D's Power zoom capabilities.

Hi Michael,

Tried the A-AS mode but it didn't work. I have three PZ lenses (28-80, 28-105 and 70-200) which did not work with the additional A-AS modes. The power zoom works in P and A mode of the lens. But none of the other features listed in the PZ1-P SLR manual. :-) Oh well...

Thanks for your reply!

Chelo

I should mention, Chelo, that even using just the standard power zoom will improve steadiness for shooting, especially with telephoto. It does help keep handheld shots more steady compared with operating the zoom ring by hand. This combined with the SR feature should be an even greater advantage.

Unfortunately, my PZ-1p film model does not use rechargeable batteries, but with the K10D, the extra power requirement is easier to accomodate.

<p>Hello Michael,<br>

Having bought second-hand about a year ago a Pentax Power Zoom 100-300mm lens, I have followed this discussion with interest. I have both a Pentax K-5 and K-5 IIs. I have downloaded the manual from Pentax and tried some of the pages with limited success. I have thed the P and A positions and they work. I am unsure of the AS position and the button. I get nothing on the screen on using these and the button. The button I have has a small knob on it which allows it to be rotated. Do you know anything more about this feature?<br>

Terry</p>

<p> </p>

<p>It's my understanding that basic power zoom will work on digital bodies but the more 'advanced' features generally aren't implemented.</p>

<p><a href="http://www.mosphotos.com/PentaxLensPowerZoom.html">This page</a> explains these features a bit.</p>

<p>Suggest looking at the manual for Pentax PZ-1p (chapter 10, 'Extended Power Zoom functions', p.78) for explanation of how these features were intended to work. </p>

<p>I think you'll see that basic power zoom works. You might find that power zoom lens automatically retracts to shortest length when camera is switched off (not sure if this was implemented for digital bodies or not). The other three features appear to require body support, as you would hold 'AS' (auto-set?) and turn the Tv e-dial to select which of the three modes (Zoom Clip, Image Size Tracking, or Zoom Effect) to use, and use the Zoom Set pushbutton on the lens to both set the length when configuring (with AS) and also on 'A' when shooting to activate the feature.</p>

<p>As an experienced user of these lenses, I can tell you everything you need to know about this amazing and underrated set of features!<br>

The pushbutton and switch labeled P/A/AS on some lenses and PZ/AZ/MODE on others concern the auto-zoom functions. How they work depends on the camera body you have it attached to, and what firmware it has. <br>

P or PZ means "power zoom", you control the zoom manually as with any other lens, except the motor does the work for you and all you have to do is turn the ring slightly. In this mode, the camera does not control the zoom motor at all, except to reduce the lens to its smallest physical size when you switch the camera off. This type of lens is significantly easier to use than a traditional zoom lens which requires more extensive manipulation of the controls, and any additional drain on the battery is insignificant. Zooming the lens electrically will also adjust your flash unit and keep the subject in focus without having to half-press the shutter release.<br>

A or AZ means "auto zoom", and this is where having of a zoom motor really comes in handy. There are several modes of automatic zooming you can select:<br>

The first auto-zoom mode works very much like the auto-focus on "servo"; it tracks your subject with the zoom and focus simultaneously, keeping it sized consistently in the frame. This is useful for tracking moving subjects such as players on an football field, cars on a racetrack, animals in their natural habitat, skiers, or anything that moves about quickly. Depending on the camera, the pushbutton may is used to focus and lock the subject's size in frame. <br>

Another auto zoom mode is memory or "paper clip", where you can preset a focal length and then instantly recall it by pressing the button. On some cameras, you can preset two focal lengths and press the button to alternate rapidly between them. As you can imagine, this is a highly useful feature for action photography, as it allows you to snap back to your optimum focal length without even altering your grip! If I am using a hood or filter stack which causes vignetting at wide angles, I often use this feature to preset the shortest focal length I can get without vignetting.<br>

The third and least common auto-zoom mode is the "zoom effect" or "zoom during exposure" mode. This is more of a specialist feature, but it does create interesting effects for fireworks and lighting displays. This feature must be used with a tripod, of course, and you'll probably want a cable release, but it takes all the hassle and guesswork out of this technique. After you set your desired exposure, the camera exposes half the time with the lens at whatever focal length you set, then zooms in quickly during the second half of the exposure, creating a radial effect. You can have the camera zoom out, instead. The motor makes this technique much easier, since there is no need to touch the camera, and the action of the motor is perfectly smooth. Not all the auto-zoom cameras can do this, but the best of them can.<br>

I know of no firmware that allows the auto-zoom features to be used on any digital camera while shooting video, although that would be quite useful. The zoom motor in your lens will not work at all unless the camera has the two extra pins in the lens mount that provide power to the zoom motor. Some later models still have the pins, which are also used to provide power to lenses which have internal focusing motors.</p>