Leica Pradovit CA 2500 vs Pentacon Aspectar 150 A

[sanjay_chaudary]

<p>Hi,<br>

I have a Leica Pradovit CA 2500 35mm slide projector with Leitz Wezlar 90mm colorplan lens.<br>

My uncle presented me with a Pentacon ASPECTAR 150A projector which comes with a Meyer Optik Gorlitz Diaplan 80mm , f2.8 lens.<br>

The bulbs are different . The pentacon has Atlas A1/21 - replacement for CDS , 100w SCC B15S and says made in UK. (It was replacement sourced from my local shop). It is huge and looks like one of the old transistor valves.<br>

The leica has EA-EHJ 24v bulb.<br>

The pentacon is portable, lighter, uses manual advance. It can store two slides. It is a tallboy design (vertical) while the Leica has horizontal design (enclosure).<br>

The pentacon lens is at higher position than the Leica. It gets quite hot and doesn't have cooling mechanism.<br>

A few things that amaze me : At the same position, the pentacon projects larger images, which are also warm. I do not see much difference in sharpness.<br>

A) Is the Meyer Optik lens as good as the Leitz lens ?<br>

B) I do not understand how the Pentacon projects bigger images . ( Maybe 80mm and tallboy position)<br>

C) Is the additional warmth in Pentacon Image due to the difference in lamps?</p>

<p>Thanks all.</p>

 

[john_shriver]

<p>Bigger image means that you have a shorter focal length lens. Standard lenses on Leica projectors are often 90mm. But there are other focal lengths available -- if you can find them for the right mount. (Longitudinal compatibility between Leica slide projector models can be poor.)<br>

The Pentacon probably puts a lot more heat on the slide, and likely more UV and IR light. All are bad for the slide film's color stability.</p>

[Robin Smith]

<p>The Pentacon does not have a tungsten halogen bulb, it has the older larger tungsten bulb and they are much less efficient and last less time. This is why it appears warm. Tungsten halogen is better as the light is whiter and more powerful. You may not see much difference in sharpness as this will be largely dependent on how sharp your slides are. The Colorplan was one of the best projection lenses (its a 6 element lens), but with projectors, although the lens is important, I have always thought the cooling system and accuracy of gate alignment and brightness of the resulting image is the thing that often lets a projector down, not the lens. As John says, the lenses are not the same focal length so the image size they project will be different.</p>

[Gus Lazzari]

<p>The Leica Pradovit CA 2500 was an innovative marvel in several ways, but mostly for it's '<strong>single-handed</strong>' high speed slide exchange.<br /> The result? <br /> A "<strong>short time in darkness</strong>" - This aided the audience in not experiencing eyesight issues caused by the build up of repeated <em>pitch dark to bright light</em> viewing.<br>

(A big advantage of the complex dual projector "lap dissolve" set-ups.)</p>

[Robert_Lai]

<p>I have the Pradovit 2500, and once you keep the motor bearings oiled (mine had seized from getting too dry), it runs like a champ. The fact that it takes a long time for the slide to pop in one of these machines is an indication of how efficient the cooling is.</p>

<p>I also have a Kodak Ektagraphic. These are also fine machines. Navitar makes a "bright light" kit that produces higher lumens. There is a super bright light kit that eliminates the heat shield glass altogether. Navitar recommends that the slide be shown for less than 1 minute with that unit. These units use a 300W halogen bulb. Just out of curiosity, I put a slide into the projector with the super bright "presentation" unit that lacked the heat shield glass. The slide seemed fine for about 1 minute. After 2 minutes, it started to visibly deform and melt. Beyond that, the cardboard slide mount started to smoke, so I stopped the experiment. I have since put a standard heat shield glass in that Navitar projection unit.</p>

<p>My point is not to talk about the Kodak projectors, but just to point out that 500 W is a lot of heat to pump through a 35mm slide. If you repeatedly project the same slide with that projector, you can expect deformation of the slide as well as fading. A lot of my lecture slides from the old days when I was teaching show fading from repeated projection.</p>

[JDMvW]

<p>Meyer was a sort of 'bargain' line for Zeiss at the beginning, but in the DDR it was melded into the great VEB Pentacon by the end (first into Jenoptik). There are some Meyer lenses that have mechanical problems, but most of them are optically just fine.</p>

<p>'Just fine' is unlikely to equal Leitz, but you have both - try them and compare. Given sample variation in even the best brands, it's difficult to make an ex cathedra case.</p>

<p>At their best, the DDR projectors could be quite stylish, though.</p><div></div>