Talk:Tessar

Bokeh

Tessars are known to have very smooth bokeh. I think it's worth a mention - if someone cares. Especially if someone who is down with technicalities can explain how and why. 90.224.107.201 (talk) 13:15, 1 July 2008 (UTC)

Optical design has appeared to move on.

Every few decades, a craze comes back for these designs. The world seems to have largely moved on and adopted other designs. What was the dead end for these designs? There must have been a performance limitation that they encountered. Can any optical engineers share some wisdom on this matter? —Preceding unsigned comment added by 69.157.172.161 (talk) 02:48, 3 December 2009 (UTC)

Reply: The reason why is that they ghost easily. They're okay stopped down but you can't make them particularly fast. The older ones were all F3.5 and slower while the "new" ones top out at F 2.5/8. That being so, the rule is to stop it down four stops from the maximum to make it crisp. If it helps you remember it, Tessar has four elements so stop down that many times. Newer designs do everything tessars do more elegantly, with higher contrast and saturation and fewer problems. Once stopped down, they'll work fine and there's no reason not to use them in except that you can always find something better. —Preceding unsigned comment added by 69.157.177.74 (talk) 19:26, 3 May 2010 (UTC)

Is there a dead-end ? I thought near-classic Tessars appeared on simple digital cameras and mobile phones. The name at least lives on in current + future products. - See Nokia 808 PureView. --195.137.93.171 (talk) 05:10, 24 June 2012 (UTC)

maxiumum aperature

According to this page the 45mm rokkor f/2.0 pancake lens is a tessar-type.

http://www.rokkor-x.narod.ru/user_manuals/rokkors_schems/

(I have one, I use it as a Tiltshift on my nikon, it's fantastic). —Preceding unsigned comment added by 67.180.72.250 (talk) 14:27, 14 March 2011 (UTC)

Nokia_808_PureView#Lens - Not a 1-group lens !

I think you mean no relative movements among the elements. That's just a simple 'prime' (not zoom : fixed-focal-length) lens - (NB In some primes, the front element doesn't move while focussing eg 'Internal Focussing' in Nikon terms). In terms of '5 elements in 3 groups', usually groups are defined by air-spaces between them. Elements within a group are cemented together.The cemented faces have the same shape, so the cement layer is thin and locally-parallel. (I don't think we need consider liquid-filled gaps here - they're extremely rare).

Best link I've seen for the PureView Lens is PureView The Tech Behind Nokia’s Salvation - SlashGear. Looks like 5 elements, 5 groups and the text says "a complex five-lens assembly with a range of aspheric surfaces".

Please correct this here, and in Nokia_808_PureView#Lens. NB They are calling it 'Tessar', but I doubt if even the marketing departments would call a fixed lens 'Vario-Tessar' - zoom is purely a software function - digital zoom !

--195.137.93.171 (talk) 05:17, 24 June 2012 (UTC)

Tele-Tessar

Some Telephoto lens versions were made for Rollei cameras, and also under licence by Voigtlaender under the name "Color Dynarex". Citation

There may be better sources, but the above would be a starting-point for a new sub-section.

Shouldn't Tessar#Vario-Tessar be a sub-section 3.3, not 4 ?

--195.137.93.171 (talk) 05:35, 24 June 2012 (UTC)

Vario-Tessar

Do lenses named "Vario-Tessar" have any relationship at all to the original Tessar design? Chris Fynn (talk) 17:30, 23 August 2013 (UTC)

'Werra' river wrong

Hej, it may be right, that the 'Werra' brand is named after a river, but not the river that runs through Jena. This river is called 'Saale'. Oliver Hisecke (talk) 13:05, 15 January 2018 (UTC)

Focussing

At the second paragraph of https://en.wikipedia.org/wiki/Tessar#Focusing_methods it is claimed that any lens can focus by moving it closer or further away. I guess it would be a good idea to add a reference to this claim. AGermanBeck (talk) 19:43, 16 September 2019 (UTC)