[RDP]

So I've been lusting after a DA 15/4 for quite a while, and the price is so attractive right now that I'm having a hard time not buying it. But... something that I'm interested in trying my hand at is astrophotography, and I know that f/4 is really too slow. The other lens I've been eyeing is the Rokinon/Samyang 16/2. While it would be much better for astro work, I prefer what I've seen from the DA 15/4 for everything else (color, contrast, distortion, AF, size, build) with the possible exception of sharpness, where they seem comparable. I would love to have both. I can only afford one. Any and all advice is welcome.

-Robin

[Conqueror]

I've got both.

Do you have the OGPS1 unit or K-3ii? These will both be of benefit to the 15mm DA in particular, it will allow you to do a longer exposure (compensating for the f4 max).

I'm not convinced my 16mm Samyang has infinity set correctly - this is a common problem I think. I haven't got round to fixing it just yet.

I reckon the DA 15mm is more versatile. Its smaller, light, marginally wider, infinity is set right, build quality immense, very good flare handling, has AF if you need it.

Both are good. If you only want to do astro the 16mm might get the nod due to aperture. If you want to do other things also, you might swing towards the DA 15mm.

[RDP]

Thanks for the quick response. I have a K-3. If the OGPS1 will allow for long enough exposures with the DA 15/4, then I can stretch the budget to allow for it (I'd already been thinking along those lines), as I think that would be preferable. I have read many reports about the infinity stop problems with the Samyangs, along with the cautions to make sure you get a good copy, but those aren't deal-breakers in the least. I do need to make a decision fairly soon, as my wife and I are going on vacation in just a few weeks to Cayman Brac, and the night sky there is fantastic!

-Robin

[bjolester]

I only have experience with the HD DA15/4, a lens that has a permanent place in my camera bag. It is a wonderfully versatile lens, compact, relatively robust, very sharp and has superb rendering. Although I am very satisfied with the DA12-24/4 for northern lights photography, which is a favourite niche within photography for me, I was eager to test the HD DA 15/4 to see how it compared to the DA12-24. I had already studied the lens review of the SMC DA15/4 at lenstips.com, one of the few review websites that test lenses for coma. This test showed very pronounced coma with the DA15 at f4, but there is a dramatic improvement when stopping down to f5.6. So I checked the performance of the HD DA15 last winter, when there was a very strong spell of northern lights, and in many ways the results at f5.6 were very impressive. However, I have moved away from the HD DA15 for northern lights photography, because the DA12-24 is so good. The DA12-24 is remarkably sharp from the centre to the corners even wide open, coma seems well controlled, and with northern lights no lens is really wide enough. 12mm is significantly wider than 15mm.

Lenstip.com has reviews of both of the lenses you consider, well worth a readthrough:

http://www.lenstip.com/380.1-Lens_review-Samyang_16_mm_f_2.0_ED_AS_UMC_CS_Introduction.html

http://www.lenstip.com/312.1-Lens_review-Pentax_smc_DA_15_mm_f_4_ED_AL_Limit...roduction.html

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Last edited by bjolester; 01-26-2016 at 08:10 AM.

[bjolester]

HD DA15 at f5.6

[THoog]

I also have both lenses, and while I haven't used them for astrophotography, I would say the DA15 is more useful for general-purpose work, being much smaller and AF. The Samyang 16/2 is useful for low-light work and works well with LiveView + focus-peaking when you have time to set up a shot, but it takes up a lot more space in the bag. I haven't had issues with infinity on mine (the 14/2.8 is another story - I have an early "gold-ring" copy and I'm still fiddling with the calibration).

[FantasticMrFox]

The Samyang primes are regarded as among the finest lenses on the market for astrophotography. Many Nikon and Canon FF shooters use the Samyang 14 f/2.8 over native offerings five times as expensive, due to its high sharpness and essentially non-existent coma.

[fuent104]

15mm f4 will be of little use for astrophotography. Get the 16mm, take it on your trip, and return it it'd you don't like it. If you can also afford the OGPS-1, the combination would probably be great.

[csa]

Get the 16mm, take it on your trip, and return it it'd you don't like it.

Is this really fair to the seller? I can see returning a defective lens, but taking one on vacation to use for free, then sticking the seller by returning it because you now have no need for it?

[northcoastgreg]

While I don't own the Samyang 16mm, I do own a couple of other Samyang derived lenses (the 10mm and the 7.5mm fisheye). Generally speaking, what the Samyang lenses provide is fast apertures and very good edge to edge sharpness. They also are fairly well corrected for coma, and therefore make good astrophotography lenses. The DA 15, on the other hand, suffers from fairly wide field curvature, reduced resolution toward the edges, and fairly significant coma. Plus it's f4. While you could probably get fairly decent astrophotography images out of the lens (if you used OGPS1 and cropped out the offending edges), it's obviously not the best tool for that particular job. Where the DA 15 excels is in the aesthetics of the image: color, contrast, rendering. It's a true art lens (as opposed to the Sigma "Art" lenses, which are, in reality, high performance, rather than "art" lenses). With its superb flare control, it captures more color data (and enhances that which it captures) than any of the Samyang derived lenses. The consequence are images that look great and perform very well when it comes to the aesthetics of the image (although you may be sacrificing a bit on the edge and corner resolution). In comparison, the colors that come out of my Samyang 10mm seem flat and uninspired; nor can all manner of PP tricks (e.g., cranking up the saturation) make up for the difference.

If you're planning on getting a lens primarily to do astrophotography, get the Samyang 16mm. If you're primarily going to use the lens for non-astro photography, get the DA 15.

Also, keep in mind: even if you choose to get the DA 15, that doesn't mean you can't get one of the Samyang lenses (either the 16mm, the 14mm, or the 10mm) for astrophotography further on down the line, when your budget allows for it. The 14mm is cheaper than the 16mm and is FF, while the 10mm would provide a complimentary FOV to the DA 15.

[THoog]

BTW, LensRentals.com has both lenses, if you want to try-before-you-buy.

[Conqueror]

With its superb flare control, it captures more color data (and enhances that which it captures)

I've definitely noticed this between the two (DA 15 gives good color).

We need to be a bit careful getting bogged down with apertures... you will see good astro results from relatively slow Sigma zooms... the 8-16 and 10-20 for instance

I think if you are going to do a lot of astro then yeah you can't rule out the 16mm f2 for its aperture and coma BUT if astro will only be 20% of your usage of the wide angle lens...

So in short I agree with northcoastgreg

Not my picture below... but a consideration! (when you are out in the field or backpacking this may or may not be a big deal)

[csa]

BTW, LensRentals.com has both lenses, if you want to try-before-you-buy.

Excellent idea!

[RDP]

Wow! So many helpful responses. Seeing the two of them side by side is a real eye opener. I hadn't quite realized the vast size differential. To add further context, right now, my widest lens is my 18-135. I have never tried any astrophotography, but the night sky has always fascinated me, back to my youth. Northcoastgreg, your comments sum up the dilemma I'm in quite well, and is really making me evaluate how much of what type of shooting I envision doing in the future. I think I am going to give myself a couple more days to think on this before making a decision, but right now I'm leaning toward the DA 15/4 and OGPS1, and adding a Samyang down the road if the astro bug catches me. If I do decide on that, I might rent the Samyang just for this trip, anyway (provided She Who Must Be Obeyed is on board ).

-Robin

[bobbotron]

I have the 8mm rokinon - I like it quite a bit for star trails, but like others have said above, it is a big lens. I also have the zenitar 16mm f2.8 fisheye lens. It's nice and compact, you can buy them new off of ebay. Another lens to consider!