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10-08-2016, 02:39 AM   #361
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Indeed. So Irix 15mm = double priced samyang "14/2.8" with filter threads. Same stuff, higher price. I wonder if they really did anything with notoriously bad QC.

10-08-2016, 02:42 AM   #362
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QuoteOriginally posted by MJKoski Quote
Indeed. So Irix 15mm = double priced samyang "14/2.8" with filter threads. Same stuff, higher price. I wonder if they really did anything with notoriously bad QC.
Both lenses are actually different with different optical formulas.
10-08-2016, 02:52 AM   #363
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QuoteOriginally posted by MJKoski Quote
I wonder if they really did anything with notoriously bad QC.
Reputation sticks. As far as I can see, the "notoriously bad QC" reputation mostly came from the early 14mm and 8mm Fisheye copies--that is, the incredibly low-priced serious lenses Samyang launched to establish itself as a serious player. Were there any excessive QC issues with, say, the 135mm f/2 or the 24mm f/1.4, those lenses which in relation are quite a bit more pricey?
10-08-2016, 03:48 AM   #364
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Yes Mistral, of course they are different lenses but similar use cases for both which is why I put it in quotes. Bad QC was especially problem with the 14/2.8 and somewhat 24mm 1.4. And now there is that premium 14/2.4 which was not coincidence after all but it costs fair bit more than this Irix. So perhaps the QC boost will be with the premium line.

10-08-2016, 03:50 AM - 1 Like   #365
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"badmouthing is especially a problem for lens and camera manufacturers"
10-08-2016, 05:47 AM   #366
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Hope I am not repeating something posted by another Pentaxian, but there is a full test of the Irix 15mm with comparisons to the Rokinon/Samyang 14mm on LensTip.com - lens review, lenses reviews, lens specification - LensTip.com. Best qualities: resolution, distortion control, control of all chromatic aberrations, build quality (Blackstone version); worst qualities: "monstrous" vignetting (over 3 EV in corners on FF) and flare. The vignetting, of course, can be corrected or at least substantially mitigated in PP fairly easily.
10-12-2016, 01:59 AM   #367
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QuoteOriginally posted by WPRESTO Quote
... worst qualities: "monstrous" vignetting (over 3 EV in corners on FF) and flare. The vignetting, of course, can be corrected or at least substantially mitigated in PP fairly easily.
... but the flare's a doozy!
10-12-2016, 02:57 AM   #368
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3 EV of vignetting might be easily fixed, but it comes with a punishment - say hello to a lot of noise. And if you need to lift exposure over the whole image anyway, it gets even more ...

10-12-2016, 03:48 AM   #369
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There are few "perfect" lenses. The question: what trade-off is more acceptable for your images and photo-psychology. In an UWA, is reduced IQ and increased distortion an acceptable trade for greater flare-resistance? Does resolution over-ride any other shortcomings? Are poor corners OK if contrast and color rendition are especially good? It might be possible to get a near-perfect lens of normal to near-normal focal length, for FF, say from 35mm to 135mm, but way out, UWA and ultra-telephoto, come choices and compromises are inevitable (IMHO).
10-12-2016, 03:57 AM   #370
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But. There will be vingetting for wideangle anyway regardless of the model...you can expose little more to gain edges some light. With FF sensor you have lots of room to play. I'v found samyang vingetting troublesome because when I get vingetting, it has also nasty color tint. That is even more difficult to work with. This is on K-1.. even if there is exellent sharpness with samyand 14/2.8 @3.5 or even @2.8 that vingette with colortint is looking nasty to my eye...ones preferenses might vary.
10-12-2016, 04:09 AM   #371
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So the question arises: which lens has the best balance of compromises, the 14mm Samyang or the 15mm Irix? The S has the additional advantage of being less expensive, the Blackstone might have an advantage in build-quality (too many of us have an old bias that metal is better than plastic). I was impressed by the IQ in some posted Irix photos, for example there's a photo of a small football field, one of two posted with a sample set, that has the box with scoreboard on the far right, and two advertising strips, one blue the other red, near field level on the left. Clicking on the "+" you can read the score board and the two signs, very good for the edges of an UWA.
10-12-2016, 04:46 AM   #372
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well, the Samyang is indeed sharp, but it has that "mustache" distortion. The 12mm Laowa is reported to have much less distortion and perhaps nearly as sharp. Not sure about the Irix yet.

Personally, I'm rather intrigued with the idea of a 11mm or 12mm Full frame lens mounted to a shift adapter mounted to the new Sony A6500 -- should make for an excellent architecture setup.

M
10-12-2016, 05:24 AM   #373
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Laowa already has shift adapter for that 12/2.8 for Sony FE mount. It transforms it into 17/4 shift lens for A7x system. Mirrorless Sony system has received few goodies impossible with DSLR bodies during a period of one year:

-Loxia 21mm (Heck of a lens to beat)
-15mm f/2 wide angle (FF)
-Laowa Shift adapter for 12mm

Trend seems to continue.

Last edited by MJKoski; 10-12-2016 at 05:30 AM.
10-12-2016, 05:35 AM   #374
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A short registration distance does open opportunities. Look at some of the ultrawides made for M-series Leicas, including the legendary Zeiss Hologon. Is it really better than the reverse-telephoto designs for SLR-DSLRs? It has far, far fewer lens elements, which generally translates into greater contrast and flare resistance, but it came with a special ND filter that was graduated from dark in the center to clear at the edge to correct vignetting. You can purchase a new Samyang 14mm for less the used price of that filter. Never seen a test or comparison to other 15mm lenses. People who own a Hologon probably keep it in a velvet-lined mahogany box locked in a safe, and only take it out to prove they have one.

Just checked EBAY and there are quite a few 16mm f8 Hologons on offer for about $1200 and up. The original, more desirable 15mm f8 Hologon has asking prices from about $7500 to over $28,000!! One seller is offering a graduated filter for the 16mm at $299. There was no listing for the filter made for the 15mm Hologon, but it would probably demand about double the price of the 16mm filter.

BTW, If you've never seen the optical formula for the 15mm Hologon, it's worth a search. A relatively simple essentially symmetrical design, but the middle element was very difficult to manufacture, and collimation in the mount was extremely critical. The rear element was only 4.5mm away from the film plane.

Last edited by WPRESTO; 10-12-2016 at 06:03 AM.
10-12-2016, 06:34 AM   #375
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Yeah, Hologon is funky concept. And that 15mm f/2 from Laowa has filter threads! And they are not like 95mm but 72mm instead!

http://www.thephoblographer.com/2016/09/22/first-impressions-venus-optics-la...mm-f2-sony-fe/

I have also used Leica WATE with Sony A7r1 and that was quite something. Miniature "zoom" with ultra high IQ across the field. Now I'm holding this 15-30/2.8 in my hands and thinking "WTF".
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