That's why pros like 1.4x converters - that's only one stop. A 3X is
probably more than three stops it occurs to me, given that
relationship but I'm not sure. They are not that popular.
Andrew Fildes
afildes@xxxxxxxxxxxxx
On 27/02/2007, at 9:06 PM, Scott Peden wrote:
>
> Oh, 2 stops for a 2 X teleconverter and 3 stops for a 3 X
> teleconverter.
>
> Got it, thanks Andrew!
>
>
>
> -----Original Message-----
> From: olympus-owner@xxxxxxxxxx [mailto:olympus-owner@xxxxxxxxxx] On
> Behalf
> Of Andrew Fildes
> Sent: Tuesday, February 27, 2007 2:01 AM
> To: olympus@xxxxxxxxxx
> Subject: [OM] Re: spam: Re: Vivitar Automatic Tele Converter 3X-21
>
>
> I better do something photographic tonight!
> Two stops - that's two clicks up on the lens. So f2-f2.8-f4. So if
> you use a 2x teleconverter to make a 50mm f1.8 lens into a 100mm its
> maximum aperture will be about f3.7.
> That 3.8 Hanimex (probably closer to f4) with a 3X is three stops up
> so max aperture should be f11 or a hair under. That's pretty dim.
> F stops were based on the original Waterhouse stops I think (Metal
> plates with holes of various diameters) and is a logrithmic scale -
> 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32, 64.
> Andrew Fildes
> afildes@xxxxxxxxxxxxx
>
>
>
> On 27/02/2007, at 8:49 PM, Scott Peden wrote:
>
>>
>> I got it 'cheap' last month, less than a 20 dollar bill after
>> shipping, I
>> had only put a bid on it to watch it, and on occasion I get stuff
>> that
>> cheap.
>>
>> I didn't understand everything you mentioned.
>> Using a 3.8 lens, that would make it about a 6.3 right?
>> Using a f8 it would be a f10?
>>
>> Actually I know I didn't understand, the confusion must be 'stops'.
>>
>> How many numbers is an F stop? Or is this that 1.4 times itself
>> thing?
>>
>> I have a 2 X Vivitar too, rather nice considering it isn't a Zuiko,
>> but it
>> does lose some clarity, I didn't check it out across the room
>> against the 3
>> X, maybe I can do that during the thunderstorms tomorrow hen I
>> don't want to
>> be outside.
>>
>> Ahh.. I have a book and I understood something, it is the 1.4
>> thingy. SO I
>> multiply 3.8 or 8 times 1.4, two times to get an idea of where my
>> new F stop
>> is likely to be.
>>
>> f3.8 x 1.4 = 5.32 x 1.4 = 7.5... acceptable if the glass is any
>> good.....
>> f8 x 1.4 = 11.2 x 1.4 = 15.7 that's going to be fun......
>>
>> And again, my shutter speed should be 1/the lens mm?
>> So a 210 mm lens with 3 x teleconverter should have a shutter speed
>> somewhere around 1/600?
>>
>> Scott
>>
>>
>>
>> -----Original Message-----
>> From: olympus-owner@xxxxxxxxxx [mailto:olympus-owner@xxxxxxxxxx] On
>> Behalf
>> Of Piers Hemy
>> Sent: Tuesday, February 27, 2007 1:28 AM
>> To: olympus@xxxxxxxxxx
>> Subject: spam: [OM] Re: Vivitar Automatic Tele Converter 3X-21
>>
>>
>> I remember getting a 3x TC decades ago, thinking it woul be the
>> answer to
>> not being able to afford longer lenses. It will cost you 2.5 stops
>> by my
>> reckoning - an f/2 aperture will have the effect of f/6; an f/4
>> the effect
>> of an f/12.
>>
>> Do I sound very unenthusiastic?
>>
>> --
>> Piers
>>
>>
>> -----Original Message-----
>> From: olympus-owner@xxxxxxxxxx [mailto:olympus-owner@xxxxxxxxxx] On
>> Behalf
>> Of Scott Peden
>> Sent: 27 February 2007 06:43
>> To: Scott Peden
>> Subject: [OM] Vivitar Automatic Tele Converter 3X-21
>>
>>
>> Can anyone tell me what quality this is? It is 58 mm long or 2.25
>> inches
>> long.
>>
>>
>>
>> Anyone know how many F stops I lose when I use this?
>>
>>
>>
>> I tried googleing this a couple of times and can't find out anything.
>>
>>
>>
>> I just put it on a 3.8f 210 mm Haminex lens and the initial tests
>> (indoors,
>> corner to corner in my bedrooms) amazed me, I thought I was using
>> my nicer
>> 2X Vivitar lens that is about 1.5 inches thick. I've got to have good
>> weather to try this out where I have been shooting the Red
>> shouldered hawk.
>>
>>
>>
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