[steven smith]

I'd like to hear some opinions: I'm useing a K10d, wuld like to purchase the above mentioned lense. Opteca,Samyang, , ect, An arm and a leg I cannot afford.

[Ira]

Have you looked at the Vivitar for $349? (You just triggered my LBA, but no--I can wait.)

I quick-checked the Samyang Review, and in addition to manual focus (like the Vivitar), it doesn't display aperture info and you adjust via the ring. I may be wrong, but it looked like the Vivitar retains camera control of the aperture.

Okay--I'm waiting for someone to tell me I'm wrong.

Also, these are all slow focusing, which in portrait situations is no big deal. But if I was going to use manual focus which I do anyway, I would go manual metering--and instead, buy a great old piece of Tak glass like the 85 1.8 or 1.9 for the same price or less than the Vivitar.

[omega leader]

All brands of this glass have an 'A' setting. Everything is automatic except focus.

Apaprently quite sharp wide open, however I would recommend a split prism. I got one for my 50mm 1.4 and the DOF is smaller on this thing so I think it would be even more necessary.

I have to say from what I've seen I'd take this over an old Tak.

Just my opinion.

[RioRico]

Back in the day (full-frame 35mm film etc) a fast 85mm *WAS* a close portrait lens. You used 100-105mm if you wanted to be back a bit, 135mm if you wanted a face-flattening close-up from further away. At 85mm, f/1.5 gives razor-thin DOF, so it's great if you want eyeballs in-focus and everything else fuzzy or at least soft. 85/2 lenses were more common, less demanding, lighter and smaller, and less expensive.

Now APS-C sensors are 1/2 the size of 35/FF, and with a crop factor of 1.5, an 85mm has FOV equivalent to 127mm -- it's no longer a CLOSE portrait lens, even though it still has the same DOF and perspective no matter the frame size. Now you'd stand back a bit, or only get ONE eyeball sharp and everything else soft. For close work, a fast 50-55-58mm approximates the old 85 usage.

I'm not trying to dissuade you from buying that (or any) 85/1.5 -- I'd love it myself, right now I have two 85/2's -- but ask yourself if the expense and weight are justified by the pictures you want to make. Very likely they are, but think about it. Have fun!

[JeffJS]

Back in the day (full-frame 35mm film etc) a fast 85mm *WAS* a close portrait lens. You used 100-105mm if you wanted to be back a bit, 135mm if you wanted a face-flattening close-up from further away. At 85mm, f/1.5 gives razor-thin DOF, so it's great if you want eyeballs in-focus and everything else fuzzy or at least soft. 85/2 lenses were more common, less demanding, lighter and smaller, and less expensive.

Now APS-C sensors are 1/2 the size of 35/FF, and with a crop factor of 1.5, an 85mm has FOV equivalent to 127mm -- it's no longer a CLOSE portrait lens, even though it still has the same DOF and perspective no matter the frame size. Now you'd stand back a bit, or only get ONE eyeball sharp and everything else soft. For close work, a fast 50-55-58mm approximates the old 85 usage.

I'm not trying to dissuade you from buying that (or any) 85/1.5 -- I'd love it myself, right now I have two 85/2's -- but ask yourself if the expense and weight are justified by the pictures you want to make. Very likely they are, but think about it. Have fun!

The APS-C sensor is 2/3 of a 35mm frame (23.4 x 15.6 mm), not half..

The 85 f1.4 isn't that heavy of a lens. Probably heavier than the 85 f2 Tak but not so heavy that it becomes unusable. Whether or not I would bother with a split screen would depend on my eyesight and the camera. On the K20d I have a Katzeye and it definitely helps. On the K7 however, I find I don't need one. At f1.4 I've found the lens to be plenty sharp with the usual DOF caveats.

[UnknownVT]

The APS-C sensor is 2/3 of a 35mm frame (23.4 x 15.6 mm), not half..

Sorry to be pedantic -

Actually RioRico was more correct by area....

23.4mm x15.6mm = 379.08 sq mm

Full-Frame is
36mm x 24mm = 864 sq mm

so APS-C is actually 43.875% of a Full-Frame

Just to be sure -
if we took a piece of paper and wanted half the size -
we'd cut it in half......
that is by area,
not by linear (one dimensional/length) measurement -
the linear scale would be the square root of 2.

However in mitigation, focal length coverage is calculated by the ratio to the diagonal of the film/sensor frame and this is linear
- that's where the crop factor comes from.

85mm was a close portrait lens for Full-Frame - since APS-C has a crop factor of 1.5x
- to get the same equivalent focal length one would need about 57mm.

So a cheaper and more common 50mm f/1.4 or f/1.7 lens would probably be more suitable -
which would be a 75mm equivalent in FF.

[Marc Sabatella]

I'm moving this the the SLR Lens forum, as this is about lenses, not cameras. Do note there are quite a few existing threads on this speciifc lens (which are all the same - made by Samyang, sold under lots of different brand names); you might want to check them out.

[braver]

Or, you can get the Pentax 1.7 teleconvertor and use it with the 77mm!

[Jasvox]

Or, you can get the Pentax 1.7 teleconvertor and use it with the 77mm!

Which gives you a 130.9mm? How is that in anyway similar to an 85/1.4?

Jason

[JeffJS]

Sorry to be pedantic -

Actually RioRico was more correct by area....

23.4mm x15.6mm = 379.08 sq mm

Full-Frame is
36mm x 24mm = 864 sq mm

so APS-C is actually 43.875% of a Full-Frame

Just to be sure -
if we took a piece of paper and wanted half the size -
we'd cut it in half......
that is by area,
not by linear (one dimensional/length) measurement -
the linear scale would be the square root of 2.

However in mitigation, focal length coverage is calculated by the ratio to the diagonal of the film/sensor frame and this is linear
- that's where the crop factor comes from.

85mm was a close portrait lens for Full-Frame - since APS-C has a crop factor of 1.5x
- to get the same equivalent focal length one would need about 57mm.

So a cheaper and more common 50mm f/1.4 or f/1.7 lens would probably be more suitable -
which would be a 75mm equivalent in FF.

Guess I forgot some of my math rules, taking a linear x-x and y-y instead of comparing areas. In Linear measurements, it is 2/3 but I can see where you are correct. I didn't take my statement any further because I couldn't reconcile 2/3 (linear difference) to a 1.5 crop.



Edit: More to the point of the thread, here's an f1.4 shot taken at about 5 feet, 45 (ish) degree downward angle (k7)




Here's the full sized version.

Not a portrait of course but you can get a sense of the very shallow DOF as well as the Bokeh produced by the lens. (Vivitar branded version).

[StephenMerola]

I have the Rokinon (same as Samyang). Great lens. I also have the Pentax K 85mm f/1.8. I like that lens also, but it is softer at f/1.8 than the Rokinon is at f/1.4.

[braver]

About the teleconvertor:

Which gives you a 130.9mm? How is that in anyway similar to an 85/1.4?

Well, then use it with a smaller lense, like 50mm!

[Pentaxor]

it's a very nice portrait lens and very cheap too. I would sell my copy once the Sigma 85/1.4 comes out.

[Wheatfield]

I very much like the 85/1.4 on the clipped sensor DSLR for portraits, though it is a wee bit on the long side.
I can't comment on the lens you are looking at, just the focal length and speed itself (I have an A*85/1.4)

[RioRico]

As I (think I) said above, an 85/2 or whatever retains the same perspective, DOF, bokeh etc no matter the frame size, if used AT THE SAME DISTANCE. Going to a smaller frame either gives a smaller slice of the picture FROM THE SAME DISTANCE, or drives the shooter to move closer, to fill the frame equivalently -- in which case the perspective and DOF change. That is significant if you're doing full-face shots.

Back in the day (damn I hate that phrase, but it's so usefully vague), I sometimes was known to shoot portraits with three cameras: a Minolta Autocord MF (56x56mm) an Olympus Pen-FT 35/HF (24x18mm), and a Nikon F 35/FF (36x24mm), all lensed to 80/2.8 or so. Shoot each from the same place at the same subject in the same light. Result: different bokeh (not named then) and frame sizes, but same size face and perspective. Then, after those establishing shots, move in with the MF and FF cams for more dramatic closeups.

Yeah, that's slower than a f/1.5, but the subjects were generally fellow soldiers who weren't much interested in having soft, dreamy portraits, nope. Shoot slow B&W film with red or orange filters, to emphasize every pore and scar and crease and crag.

I mentioned weight because, lacking these fancy modern high-falutin' optics, I'm most familiar with the Russian Jupitar 85's. With those, going from f/2 to f/1.5 involves about 1/2 pound, IIRC. That's a big chunk of gorgeous optics that gets its own tripod mount.