Best soft- Bokeh 50 LTM?

[fgianni]

I find the I61 L/D the most pleasing lens in my arsenal, yes even more than the summicron 35 4th or the summilux 75, but that is just me.

 

[varjag]

Coatings and improvements.

I said before that the Jupiters are Sonnar "copies," I wonder to what degree if any improvements/changes were made to the optical formulas through the years. I guess there have been some as the J8 became the J8m and there is the Helios 103 which is a derivative too right?

Jupiters up to 1953 seem to be designs of original Bertele's calculation. By 1954 KMZ has run out of Schott optical glass, and the lenses were recalculated for Soviet optical glass types. The coating process of that time IIRC was Zeiss process developed pre-war; later it was improved upon.

It's been mentioned that diagram for J-8M shows slightly different thickness/curvature of elements compared to J-8, so perhaps it was recalculated too.

Helios-103 is as mentioned a totally different design. Initially I thought too that it was a Biotar, but the story probably comes from Helios-44 2/58, and SLR lens copied from 2/58 East-German Biotar. Helios-103 at its 1.8/53 is different enough, and I now doubt it has its roots in Biotar, but it is safe to call it a typical Planar design (of which Biotar is a particular variation).

 

[Ronald M]

Summarit will do exactly what you want. A touch soft in the center and getting softer towards the edges.

 

[fidget]

No. H-103 is a Biotar symmetrical design. Something completely different.

I had read in a different thread from varjag that the H103 had some attributes of a planar lens. Is this the same as biotar?

Oops, i see that Varjag replied whilst I posted this............

 

[Bill58]

Summarit will do exactly what you want. A touch soft in the center and getting softer towards the edges.

Thanks---I guess I'll try the Summarit after I try the 3 Russians.........and my bank account has a rest.

 

[GeorgesGiralt]

Hi all !
This week end, we had a discussion about Bokeh and a lecture by an optical teacher at a French optics college.
This guy, thanks to him, demonstrated that the out of focus image is in fact a projection of the lesn stop. (he does so with a star shaped diaphragm and we saw a star shaped out of focus image).
This is why the mirror lenses have donut shaped out of focus images (because the center of the lens is masked by the mirror).
Next he said that we like out of focus images to be circular in shape and the more circular is the better because the sun is circular and since mamals are on earth, the image projected by the sun, being in or out of focus IS circular. So hte conclusion was that the more circular the lens opening, the more satisfying the bokeh will be. This is why some lenses having a 5 blade opening gave so poor bokeh. So I think that the Sonnar copies, having many blades giving a more accurate circle will be better suited than others for a good bokeh.
Hope this helps.

 

[FrankS]

There is more to bokeh than iris shape. It is also a function of degree of correction for spherical abberation of the optical design, among other things that I also don't fully understand.

 

[mechon]

Kanonski--a Polish guy w/ a Leica?

or rather Polish guy with Canon ......

 

[Sparrow]

……….. a Polish golf course!

 

[mechon]

To be exact: Kanonski sounds more like Russian name.
Kanoński - sounds like Polish born with Canon gear in his hands 😉

 

[GeorgesGiralt]

There is more to bokeh than iris shape. It is also a function of degree of correction for spherical abberation of the optical design, among other things that I also don't fully understand.

Yes, you're right, but if the opening is circular, the sperical aberation mix well with it. So the aberation is barelly noticeable. If the aperture is square, having sperical aberation will improve the bokeh because it will tend to render the square into a circle (because of the light halo surrounding it).
We where also told about astigmatism (but this is well cared for since the beginning of 20th century, so not a concern here)
So for lenses of same design, the more blades the better the bokeh will be.

 

[FrankS]

Still, there is much difference in bokeh between lenses (of different optical design) that have very similar almost round irises. To explain bokeh with only the shape of the iris is too simplistic (for some folks) but may be adequate (for some.)

 

[Xmas]

Helios-103 is as mentioned a totally different design. Initially I thought too that it was a Biotar, but the story probably comes from Helios-44 2/58, and SLR lens copied from 2/58 East-German Biotar. Helios-103 at its 1.8/53 is different enough, and I now doubt it has its roots in Biotar, but it is safe to call it a typical Planar design (of which Biotar is a particular variation).

I thought the Helios was a near copy of the late Leitz high refreactive glass but simplified summicron, i.e. a double Gauss or Cooke Speed Pancro, Planar, Biotar (or whatever ad copy you use) near copy but ratiionalised for modern production with modern glass?

Mine needs more black paint.

Noel

 

[Xmas]

Helios-103 is as mentioned a totally different design. Initially I thought too that it was a Biotar, but the story probably comes from Helios-44 2/58, and SLR lens copied from 2/58 East-German Biotar. Helios-103 at its 1.8/53 is different enough, and I now doubt it has its roots in Biotar, but it is safe to call it a typical Planar design (of which Biotar is a particular variation).

Varjag is correct...

I thought the Helios was a near copy of the late Leitz high refreactive glass but simplified summicron, i.e. a double Gauss or Cooke Speed Pancro, Planar, Biotar (or whatever ad copy you use) near copy but ratiionalised for modern production with modern glass?

Mine needs more black paint.

Too much echo here...

Noel