[peggers]

Hello all
This seems to be a grey area. The review on this lens says that it is unconfirmed whether this lens will be ok with a full frame K1
Can anyone confirm if it will be fine, or will there be a problem with shadows/vignetting at the edge of the frame?
I think I already know the answer, but am hoping I am wrong

[enoeske]

Hello all
This seems to be a grey area. The review on this lens says that it is unconfirmed whether this lens will be ok with a full frame K1
Can anyone confirm if it will be fine, or will there be a problem with shadows/vignetting at the edge of the frame?
I think I already know the answer, but am hoping I am wrong

Works great! There is some vignetting at f/2.4, but it's easily corrected in post, and above that is gone.

[Adam]

Yes, apart from some vignetting and noticeable edge softness wide-open, it does cover FF fully.

[peggers]

Thanks for those replies.
Now some more information
I plan to purchase one of those lenses to take with me to Iceland to photograph the Northern Lights (fingers crossed). Would this be a good lens for that purpose?
And, i do have an old manual focus, no auto Tamron 28mm F2.5 lens. I think this may not be ideal because since there is no A setting, it will be wide open and may not be as sharp as it could be. That lens, the BBAR MC is reviewed on this site and it is suggested that F2.5 isn't its best for sharpness. Do you think it might be ok, would I be better off going for the Pentax 35mm?

[Na Horuk]

I like my DA 35mm f2.4, but I do not have K-1. Maybe you might prefer FA 35mm f2 (made for FF sensor, but older. Same optical lineage as the DA 35mm f2.4) or Sigma 35mm f1.4 (big, heavy, but very sharp). There is also Samyang 35mm f1.4, but it has no AF. But it is Sharp and affordable, and it has A on aperture ring. Pentax FA 31mm is another good choice, people like it a lot.

Does the Tamron have an aperture ring? If yes, you can still use any aperture you want. You just have to set it by hand and use M mode with fixed ISO (not Auto ISO, not ISO range). A setting on aperture ring means the camera can set the aperture. Menu --> Enable aperture ring (very end of menus), and then M mode with fixed ISO. All other modes will default to "Av mode" which will only shoot wide open aperture. you can see if camera switched to Av mode on the back LCD.

35m and 28mm on K-1 would be good for Iceland. I would also add something like DFA 100mm macro (you can buy used, it is a top lens at a good price)
Pentax A 50mm f1.7 another affordable FF lens: https://www.pentaxforums.com/lensreviews/SMC-Pentax-A-50mm-F1.7-Lens.html

When I travel, I usually have three lenses. One (very)wide, one normal, one telephoto. That way you have almost everything covered

We had threads about Iceland trips before, you might want to search the forum.

Tl;dr: I recommend you take 28mm, Pentax A 50mm, and think about Pentax DFA 100mm. Maybe add FA 35mm or DA 40mm limited or FA 31mm limited (if you buy 31mm, you probably don't need 28mm; if you buy 35 or 40mm, then 28mm is significantly different)

[Kozlok]

Used FA31 isn’t too expensive.

[UncleVanya]

There is a used FA 35 f2 in the marketplace right now. The FA 35 is full frame and has excellent edge performance. EDIT: But now that we see a DA 35 shot made at night - I doubt it matters. Your going to get a good shot either way.

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Last edited by UncleVanya; 11-06-2017 at 09:18 AM.

Thanks for those replies.
Now some more information
I plan to purchase one of those lenses to take with me to Iceland to photograph the Northern Lights (fingers crossed). Would this be a good lens for that purpose?
And, i do have an old manual focus, no auto Tamron 28mm F2.5 lens. I think this may not be ideal because since there is no A setting, it will be wide open and may not be as sharp as it could be. That lens, the BBAR MC is reviewed on this site and it is suggested that F2.5 isn't its best for sharpness. Do you think it might be ok, would I be better off going for the Pentax 35mm?

One thing to note: the Northern Lights in Iceland are often directly overhead, sometimes horizon to horizon, so a wider angle may be desirable.
A FA* 24mm F2, while pricey, might be something to consider if you can find one. The extra speed is always useful with auroras.

That said, I like my DA 35mm f2.4 a lot, and have gotten good night sky images with it, although I've only used it on APS bodies. I would certainly try it on a K-1 if I had one, corner to corner coverage might not be that important.

[enoeske]

Thanks for those replies.
Now some more information
I plan to purchase one of those lenses to take with me to Iceland to photograph the Northern Lights (fingers crossed). Would this be a good lens for that purpose?
And, i do have an old manual focus, no auto Tamron 28mm F2.5 lens. I think this may not be ideal because since there is no A setting, it will be wide open and may not be as sharp as it could be. That lens, the BBAR MC is reviewed on this site and it is suggested that F2.5 isn't its best for sharpness. Do you think it might be ok, would I be better off going for the Pentax 35mm?

I took this with the 35mm f/2.4 and the K-1 -- Apart from not being as wide as you might need, it should work fine for some night sky shots

[UncleVanya]

I took this with the 35mm f/2.4 and the K-1 -- Apart from not being as wide as you might need, it should work fine for some night sky shots

Great shot.

[pres589]

Can we think of a better lens for the job? This seems a bit too narrow and with weak edge performance wide open I think I'd rather shoot with something else. I've never shot the northern lights (although that sounds awesome!) I don't know what kind of aperture and such would be used for best exposure and image quality.

That Tamron 28mm might do the job if you can stop down a bit and still get the shot. A Zenitar 16mm fisheye is about amount of cost and seem pretty decent if you can stop down. A DA 18-55 WR is easy to find for $100 used and is said to work well on full frame if the zoomed focal length is kept to about 24mm or longer. There have been some different 24mm lenses over the years available in k-mount and m42 what would probably work quite well. I like the idea of the FA*24 but they're non-cheap.

I hope others will chime in on these ideas or suggest their own.

[FantasticMrFox]

Everyone suggesting various Pentax primes as alternatives, yet no one has mentioned the Samyang/Rokinon/Bower 14 f/2.8 yet. THE lens for astrophotography, universally adored across systems, and quite affordable, too.

[pres589]

Everyone suggesting various Pentax primes as alternatives, yet no one has mentioned the Samyang/Rokinon/Bower 14 f/2.8 yet. THE lens for astrophotography, universally adored across systems, and quite affordable, too.

I didn't suggest it due to poor edge performance on full frame (from everything I've heard, and I believe Adam the admin has stated that he doesn't really consider it a true full frame lens due to these issues) and cost. I tried to suggest lenses that can be had for about $150 USD or so. I do like the f2.8 max aperture aspect and I know the lens is well respected when you stick it on a crop body.

[enoeske]

I didn't suggest it due to poor edge performance on full frame (from everything I've heard, and I believe Adam the admin has stated that he doesn't really consider it a true full frame lens due to these issues) and cost. I tried to suggest lenses that can be had for about $150 USD or so. I do like the f2.8 max aperture aspect and I know the lens is well respected when you stick it on a crop body.

The Irix 15mm f/2.4 should be a pretty good alternative as well.

[pres589]

If the originating poster of this thread is considering bolting a DA 35 f2.4 onto their camera, pricing doesn't seem to support purchasing an Irix 15 instead. That's my assumption of course.