Sinaron-S Digital = Sironar-S ?

[JW Dewdney]

I just came into posession of a 135mm Sinaron-digital lens, thinking I could mess around with it possibly for some macro work or with a rollfilm back (assuming it wouldn't cover 4x5) - but guess what? It DOES cover 4x5 - and THEN some!! I started really looking at it closely - and then at some web pictures of sironar-s lenses... and then at my rodenstock literature... same filter size. Same rear flange size. The paint scheme is identical - down to the magenta stripe. It makes complete sense to me that Sinar remarkets lenses for different purposes - and Rodenstock too. And it makes perfect sense to use the sironar-s's for this purpose... but I'm just wondering if anyone knows anything about this...

[Oren Grad]

In addition to the 135 Apo-Sironar-S, Rodenstock also offers a 135 Apo-Sironar-Digital. They are very similar in physical dimensions and appearance, but not identical. The easiest way to tell them apart is probably looking at the front cell; the cylindrical part of the front cell is deeper and the spacing between lettering and the colored ring is wider on the digital. The digital is supposed to reach optimal performance by f/8-11, rather than f/16-f/22. Perhaps Bob Salomon can tell us more about the specific differences.

Although the two versions of the lens may be very similar, I don't think that they are literally the same lens.

[JW Dewdney]

I thought it would make a badass 4x5 lens!

[Ted Harris]

It is not the Sironar S .... that = Sinaron SE if memory serves.

[JW Dewdney]

Yeah - it's got the deeper flange. So it's probably the rebranded apo digital. I wonder if it's significantly better than the Sironar-S... guess it really wouldn't matter since even the N already nearly 'out-rezes' the film it exposes.

[Oren Grad]

I wonder if it's significantly better than the Sironar-S...

It's not claimed to be "significantly better" in any general sense, only to be optimized for better results at f/8-11, especially when used for sensor-based imaging.

It probably will make an excellent 4x5 lens; the only question in my mind is whether the tweaks needed to optimize over a smaller field for wider apertures have any tradeoffs in typical 4x5 applications, for example at the edge of the field if you're using large movements. I have no idea.

FWIW, I've shot a test roll of 6x7 cm frames using the 90mm Apo-Sironar-Digital - a lens which, BTW, has a substantially different cross-section from either of the 90 Grandagons - and though I did not conduct any formal resolution tests, the overall character was ultra-refined, with a "look" very similar to what I'm used to from the Apo-Sironar-S lenses on larger formats.

[JW Dewdney]

Yeah... I'd IMAGINE that the 90 is still a plasmat, based on a scaled down sironar design of some sort... that might be one difference. So - maybe you're comparing apples to oranges in this particular case. I was assuming it might be a better performer if it peaks out resolution-wise at f/8. It's not as though it would be any worse at all stopped down - ! I guess it could simply be the intention is to use it for center-field, and thus, as most lenses tend to be slightly better at center of field.... well, you know what I mean. I was thinking of selling it - but I may just hang on to this.

[Oren Grad]

Yeah... I'd IMAGINE that the 90 is still a plasmat, based on a scaled down sironar design of some sort...

Actually, it's not. It's a wide angle design, looks to be a cousin of the Grandagons, with more and somewhat different elements. No resemblance to a plasmat whatsoever, except in the character of the image, which indeed looks more like an Apo-Sironar-S than a Grandagon.

Anyway, you're right, it is a bit of apples-to-oranges to drag in the 90. But do try the 135 before you make a decision - it may well be a perfectly fine lens for 4x5.

[JW Dewdney]

hmmm! okay. seems weird that they would COMPLETELY redesign that one. Guess they needed to fill a need.

[Narcissist]

FWIW, I've shot a test roll of 6x7 cm frames using the 90mm Apo-Sironar-Digital - a lens which, BTW, has a substantially different cross-section from either of the 90 Grandagons - and though I did not conduct any formal resolution tests, the overall character was ultra-refined, with a "look" very similar to what I'm used to from the Apo-Sironar-S lenses on larger formats.

Sorry to take this discussion a bit off track, but did you see how far the image circle extended to? I'm interested in a digital 90mm or 100mm for use with 6x7 for landscape and am concered about the image circle size on digital lenses. I have no means to trying one out to see.

Thanks!

[Oren Grad]

Sorry to take this discussion a bit off track, but did you see how far the image circle extended to? I'm interested in a digital 90mm or 100mm for use with 6x7 for landscape and am concered about the image circle size on digital lenses. I have no means to trying one out to see.

Rodenstock currently specifies the lens as having an image circle of 125mm at f/8-11 and infinity focus. An earlier data sheet had a specification of 140mm for f/22 and infinity focus. The diagonal of a nominal 6x7 frame of 56x70mm is 90mm, so clearly there's room for movement; at the specified circle for f/22, there ought to be room for plenty of movement. But I haven't done enough with the lens to be able to tell you how tight the coverage feels in practice at typical working apertures.

It's hard to know how to compare to the corresponding specifications for 90mm lenses intended for 4x5, because the different design objectives for the digital lens may have led Rodenstock to apply more stringent performance criteria in specifying its zone of acceptable performance.