Process Lens & Close Work

[ridax]

for anything 3-D I just use Dagors.

Or even Half-Dagors when the background is really far away (https://www.largeformatphotography.i...=1#post1623018)...

[Drew Wiley]

What does a dagor formula have to do with a 3d look? I've generally found dagors quite disappointing with respect to out of focus rendition, and not very good at extreme closeups either. But perhaps you are referring to a particular dagor construction process lens, ridax? They do render what some people have called a subtle bit of "roundness" to edges, for lack of a better way of describing it.O That's one of the reasons I still keep on hand a 14 inch dagor myself for 8X10 usage (but never use it for close-ups per se). Please re-elaborate your specifics in the context of this particular thread.

When I want really lovely background blur at the same time as good close range performance, I resort to an equivalent focal length 360 f/9 single-coated Zeiss process tessar. Someday I need to get that mounted into a Copal 3s shutter for greater convenience.

[ridax]

What does a dagor formula have to do with a 3d look? <...> But perhaps you are referring to a particular dagor construction process lens, ridax?

(1) I am not talking about any '3d look' (which sounds quite a bit mystically, and I always strictly avoid anything non-scientific). I am talking about the out of focus background rendition in 3-D subjects.

(2) I am not talking about a dagor formula. The formula has a lot of implementations very different in their spherical aberration (SA) character. And its the SA that makes the out of focus rendition different. In particular, I am referring to the Series III Dagors and their descendants - the f/6.8 ones (f/7.7 if longer in the focal length) .

I've generally found dagors quite disappointing with respect to out of focus rendition

That may just be the case which is usually described by the words tastes differ. But its also possible that you mean the foreground out of focus rendition, not the background one. If that's the case then I totally agree with you. And besides that, the Dagor's background out of focus rendition gets nice when the lens is stopped down at least to f/10 and stays as fine up to at least f/32. At f/45 it is still good but less good than at f/32. At f/64, it's already nothing special. And it's plane ugly wide-open. The Dagor's foreground out of focus rendition is terrible at any f-stop.

In fact, the topic of the OOF and the SA (not particularly in the macro range; but it's exactly the same in close-ups and in the more distant subjects - except that in close-ups, there are way more chances to have anything out of focus in the frame) was discussed here a lot over the recent decade so I really don't want to repeat all the same again. (I'll probably find the links to the previous discussions containing my own posts on the topic and post the links here when I have time to.)

When I want really lovely background blur at the same time as good close range performance, I resort to an equivalent focal length 360 f/9 single-coated Zeiss process tessar.

I move my f/9 Apo-Tesar-type and the process Celor-type lenses' front elements about 1mm or 2mm out to get a better out of focus background rendition (the pre-WWII Zeiss and all the LOMO barrels allow for that kind of movements easily; the later GDR-era CZJ ones, as well as the post-WWII barrels from lots of other manufacturers, do not). But the front element displacement makes the out of focus background rendition good from wide-open to about f/16 only. At f/22 the influence is already negligible.

What is nearly unique to Tessars and Celors is that a little modification of the barrel makes moving the front element a bit backwards possible. That builds up some positive SA in the outer zones of the pupil which make the foreground out of focus rendition look pleasant wide-open (but alas, stopping the lens down eliminates the effect).

[Drew Wiley]

Interesting. Thanks for the reply.

[Bernice Loui]

Circa 1990's
~240mm APO (red dot) Artar @f22 in barrel round iris, nearly life size or 1:1, 13x18cm Agfachrome RS100, 5x7 Sinar C with Sinar shutter.


Bernice

[Tin Can]

My male Pug, Cosmopolitan Topper loved that flower fragrance

As did my wife and even me...

Our 2 female pugs didn't care, they were a bit mean

Cosmo loved child smell, and ran to them

I bought well used rag dolls from parents, best if never washed

Only hunger got him away, then I had to hide them high up

Circa 1990's
~240mm APO (red dot) Artar @f22 in barrel round iris, nearly life size or 1:1, 13x18cm Agfachrome RS100, 5x7 Sinar C with Sinar shutter.


Bernice

[Bernice Loui]

Not LF, another pix of this flower.




Bernice

My male Pug, Cosmopolitan Topper loved that flower fragrance

As did my wife and even me...

Our 2 female pugs didn't care, they were a bit mean

Cosmo loved child smell, and ran to them

I bought well used rag dolls from parents, best if never washed

Only hunger got him away, then I had to hide them high up