Vivitar S1 28-105mm - aperture ring markings

AgX · Apr 8, 2019

This lens has two peculiarities:

-) It is designated as zoom lens and described everywhere as such, but actually it is a varifocal one.

-) The aperture ring has the the F-stops markings 8 and 22 coloured blue res. green.
Why ??

That cannot be for using a DOF scale, as there is no such
That cannot be for indicating a smaller effective aperture at the 105mm setting, as there already is such green indicator and the F 22 is a true F-stop with smaller diaphragma opening.

(There are two version of this lens, which at least differ by barrel design, but both got these coloured markings.)

Ariston · Apr 8, 2019

AgX, I never use zone focusing, but my version of this lens has distance markings (for DOF?) on the barrel in green as well. Three different distances are green, and the rest are white. They must correspond to the two apertures somehow.

By the way, I absolutely love this lens. Although, I am not crazy about the varifocal part. I don't think I even gave $30 for it. What a steal.

miha · Apr 9, 2019

Was there ever a "zoom" lens marketed as varifocal?

AgX · Apr 9, 2019

Ariston said:
AgX, I never use zone focusing, but my version of this lens has distance markings (for DOF?) on the barrel in green as well. Three different distances are green, and the rest are white. They must correspond to the two apertures somehow.

At least my model (focusing to infinity the "wrong" way, namely in anticlockwise direction) has three green lines for Meter and three white lines for Feet.
I assume it is the same at yours and you just mixed things up.

Focusing marks at varifocal lenses are differrent from standard zooms anyway. And I find this model especially irritating at focusing. I am noz shure of better to pull/push or to twist. Thus lesserr for fast action, but then it got a macro range down to 1/2 size. Though object distance at 1/2 is so small that flat objects already can be shaded by the barrel.

AgX · Apr 9, 2019

miha said:
Was there ever a "zoom" lens marketed as varifocal?

Yes. But I am likely facing this topic with wrong assumptionms as in the past some german authors explicetely applied the term zoom only on parfocal lenes (true zooms). But it turned out not all shared this approach...

Ian C · Apr 9, 2019

Although the following manual is not the same model, it is a Vivitar lens of the same 28 mm – 105 mm focal-length range. The comments regarding the different-colored aperture numbers and different-colored index marks are likely the same as for the lens you have.

See the paragraph “Variable Aperture Lenses” on page 3. It begins in the right-hand column and continues on the top of page 4 below in the left-hand column.

http://allphotolenses.com/public/files/pdfs/35cf92654172acef1657a8f50694c184.pdf

This is no different than the color coding used on other zoom lenses, such as my AI and AIS Nikon Zoom lenses.

This is only important when you read the aperture scale at focal length settings substantially different than the shortest and use the values in setting the exposure manually, such as would be the case with an external light meter or using a manually-set flash or flashbulbs. It would also have to be considered with a sensor-automatic flash, such as a Vivitar 283.

For intermediate focal-length settings, the best you can do is to interpolate between the two aperture values to get a reasonable estimate of the actual aperture.

This is irrelevant for cameras with a TTL (through-the-lens) light meter because they use the light intensity received by the built-in photocell to determine exposure. This is also taken care of automatically with a TTL automatic flash and the cameras for which it’s intended.

AgX · Apr 9, 2019

Ian, thank you for your long reply and as I already indicated it is the same at my lens:

There is a green strip mark on the right of the aperture static-mark . Together with the designation 2.8-3.8 and the 105mm setting at the zoom scale in green too obviously meaning that at the whole aperture range at the 105mm stand the effective aperture being 2/3 smaller, to be read at that green strip.

BUT this does not explain why at the aperture ring the settings for F8 and F22 are engraved in blue, resp. in green...

HOWEVER, that manual for the parfocal version on this lens has this

And as I indicated already too I thought of this (codings for the DOF scale) already. But my lens (and my other varifocal lens too) lacks any DOF scale.

As there are no better explanations so far, my best bet would be that the manufacturer used an aperture scale from a parfocal lens at the varifocal models too.

miha · Apr 9, 2019

AgX, can you perhaps share a photo of the lens extended showing the colour marks?

AgX · Apr 9, 2019

This is the other version. With the distance values on the focusing barrel. But the aperture ring with its two coloured values and the two static marks is nearly identical to mine.

As this got he distance values on the focusing barrel (and no lines instead on the static barrel), this version even may be a parfocal lens, with the standard DOF lines and thus coloured aperture marks that make sense:

https://www.apotelyt.com/i1/vivitar-28-105mm-28-38-960x640.jpg

miha · Apr 9, 2019

A picture of the lens in the extended position showing the colour lines would be worth a thousand words

AgX · Apr 9, 2019

My varifocal version with distance lines:

http://radojuva.com/wp-content/uploads/2013/06/vivitar-28-105-review-3.jpg

The other version with the DOF lines (parfocal)

https://www.picclickimg.com/d/l400/...IES-1-28-105mm-128-38-MACRO-FOCUSING-ZOOM.jpg

As indicated at the start, here the coloured aperture values make perfectly sense- But not at mine.

There also is a third version (parfocal too) but with slighter smaller effective aoperture of 4.5:
http://forum.mflenses.com/userpix/20096/14_Vivitar_Kobori_28105_1.jpg

Model 1 and a 70-200mm next to each other, to compare scale designs:
https://www.flickr.com/photos/framerkat/4712424839

Depending on mount the orientation of the aperture scale may be mirrored between samples.
But all aperture rings of the varifocal model, indepentand of mount and orientation of scale and type of automatic button, have these coloured figures.

Again this might be explained by per mount and aperture range manufacturing just one model of aperture ring for all lenses. Something that would not be detected at parfocal models, only at varifocal models...
Thus I still think this versatility of aperture rings is the explanation.

miha · Apr 9, 2019

AgX said:
As indicated at the start, here the coloured aperture values make perfectly sense- But not at mine.

I see now. No distance scale on the ring, colour lines on one side only...no idea on the logic behind this.

AgX · Apr 9, 2019

Parfocal and varifocal lenses have different mechanics. The varifocal lenses (I know) have a pull/push zoom at infinity, but at fousing to near the focusing barrel moves up the the zoom scale.
The space at parfocal lenses taken for DOF lines is taken at varifocal lenses by the weird distance lines.
This is the logic behind the lines.

For the logic behind the aperture rings see my last comment I added above in bold.

AgX · Apr 9, 2019

This lens has its merits, but its weird operation makes it at least irritating in operation.

Also at the FD mount the breech-lock automatic locking (basically a good idea taken over from Canon) is badly designed or manufactured and counterproductive.

miha · Apr 9, 2019

Maybe these Vivitar manuals will help you in cracking this nut: http://www.boggys.co.uk/page8.html

AgX · Apr 9, 2019

I already got them all. No hint at all...

Ariston · Apr 9, 2019

AgX said:
This lens has its merits, but its weird operation makes it at least irritating in operation.

Definitely not good for quick operation. But if you are not in a hurry, there is a lot of value, considering the price. To me, mine's worth much more than I can sell it for. The focal range is just about ideal for my purposes. There are different versions of this lens, though, and I'm not sure which I have.

AgX · Apr 10, 2019

miha said:
Was there ever a "zoom" lens marketed as varifocal?

Here a case of a Vivitar lens were even the lens is designated this way
(though with the ambiguous term auto variable focusing, explained in the manual):
http://allphotolenses.com/public/files/img/69e52a50f8fc9937cc05e21d12ef3fcd.jpg

But it differs even at one manufacturer. At my lens, there is no such designation on the lens nor any hint at the manual.

Russ - SVP · Jan 7, 2020

The Cosina made model with the 67mm filter size is a really good lens. The 72mm filter version is not nearly as good.

Vivitar S1 28-105mm - aperture ring markings

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