[Stavri]

Legend has it that he who finds a M 35mm f1.4 gets crowned king of Pentaxland, so it has been foretold....

[cali92rs]

Here is a Nikon 35mm f1.4 shot at f2.0, on a D810 (same sensor as K-1, so you can get a feel for how the DOF would look on a FF camera)





Another at f2.0





and here is one at f2.8





My conclusion is that you can get pretty good subject isolation with a FF camera and 35mm lens at f2.0 or even f2.8 while maintain a good distance to your subject (which is important for people because you don't want the big nose effect).

[stillshot2]

My conclusion is that you can get pretty good subject isolation with a FF camera and 35mm lens at f2.0 or even f2.8 while maintain a good distance to your subject (which is important for people because you don't want the big nose effect).

Ok thanks for your response! I ended up buying a Takumar 35mm f2.3 and find I can get good subject isolation in most cases and really love the bokeh when used wide open. It is actually really sharp too, but now I really want to try it on a full frame camera. If only I could afford one right now!

[pres589]

stillshot, share some images with that Tak 35 f2.3. Sounds like you're enjoying the new lens.

[stillshot2]

stillshot, share some images with that Tak 35 f2.3. Sounds like you're enjoying the new lens.

Here's a link to an album I put together of some of my favorites: Takumar 35mm f2.3 | Flickr

I think I may have to review this lens soon, as I am finding it impresses me as much as my 77mm f1.8 limited and Super Tak 50mm f1.4 do! I've been carrying this trio lately and it has been an amazing experience. I think I found my "three princesses," despite that they are not the 3 typical limiteds

[Fenwoodian]

Here's a photo taken on my K1 with a Zeiss ZF 35mm f/1.4 Distagon that I Leitax converted.

Photo taken at f/2 I believe. I really like the bokeh this lens produces at f/2. At f/1.4 the dof is a bit less of course, but it is also not quite as sharp and has more vignetting than at f/2.

I've shot alot of 35mm lenses over the years, and while the Z35/1.4 is large/heavy/expensive, in my eyes, it produces the best wide aperture 35mm images I've seen.

[stillshot2]

Here's a photo taken on my K1 with a Zeiss ZF 35mm f/1.4 Distagon that I Leitax converted.

Very nice image! Is this lens the modern Zeiss that can be bought new for around $1800? How did you convert it?

---

Last edited by stillshot2; 04-29-2017 at 10:28 AM.

[Fenwoodian]

Very nice image! Is this lens the modern Zeiss that can be bought new for around $1800? How did you convert it?

Yes, that's the lens.

I convert them myself. Done 17 so far. Lately I've also started converting the Zeiss Milvus lenses to Pentax K mount.

[lightbox]

Your K-30 has fairly poor focus sensitivity with PDAF (ability to detect OOF is the same at f/5.6 maximum aperture as at f/1.4 or f/2.0). The implications for missed focus are bad enough at f/2.0 and somewhat worse at f/1.4. If fine focus is the intent, then there are two options, magnified live view and/or aftermarket split-image screen.

Hi Steve,

This bit got my attention and am looking for some more info. Does this mean that on my K-50, which is similar to the K-30, that I cannot expect to get sharp focus on somebody's eyes below f/5.6 (at least not with the OVF)? It might explain some of the unsharp portraits I've gotten despite being certain I had nailed focus or used a not-too-shallow DoF.

I don't think I've ever used magnified live view (looking it up now).

[Na Horuk]

I don't think I would be soo dramatic as to say focus with lenses faster than f5.6 is a gamble. But DSLRs are not optimized for superfast lenses. And the AF points are big, so the focus might lock correctly - but not on the part that you wanted. With shallow DoF, this can become an issue really fast. For example, AF locks onto eyebrow instead of eye. With f8, that photo would still be fine due to DoF. At f1.4, eyebrows and eye pupil can already be too far for DoF.
So if you are using superfast lenses and need critical focus, most people here just use Manual focus and buy a focusing screen (optimized for fast lenses, maybe even with split prism, rather than the stock viewfinder which expects mostly lenses slower than f2.8. Note that a FS for fast lenses might not work great with slow lenses, might darken the viewfinder), viewfinder loupe. Or they use Live view with Focus peaking (optional, but pretty good with fast lenses) and Digital magnification (this is important, because it opens the lens aperture fully)

[stevebrot]

Hi Steve,

This bit got my attention and am looking for some more info. Does this mean that on my K-50, which is similar to the K-30, that I cannot expect to get sharp focus on somebody's eyes below f/5.6 (at least not with the OVF)? It might explain some of the unsharp portraits I've gotten despite being certain I had nailed focus or used a not-too-shallow DoF.

I don't think I've ever used magnified live view (looking it up now).

What it means is that the ability to detect an out-of-focus condition is the same at f/5.6 as at f/2.8, f/2, or other faster apertures with the K-50. This is typical for consumer-level bodies across brands. Models such as the K-3/K-3II and K-1 have a center column of AF points that can discriminate at f/2.8, but are limited to f/5.6 for the other points.

For most shooting, this is not a huge limitation, but may be a problem when fine focus is desired* and/or when using wider apertures.


Steve

* Even shooting stopped down, there is only one true point of focus. Pixel peeping demonstrates that nicely.