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02-27-2018, 10:29 AM   #1
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Irix 11mm

Here's a quick jpeg shot with my Irix 11 mm. Trying to decide if it's a keeper. Your thoughts would be appreciated.
Terry

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02-27-2018, 11:07 AM   #2
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I like mine, works great on the K-1 & KP
02-27-2018, 11:23 AM   #3
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These are sharpened a little.

---------- Post added 02-27-18 at 11:28 AM ----------

QuoteOriginally posted by longbow Quote
I like mine, works great on the K-1 & KP
I'm thinking they might be soft. I guess if I shot Raw and processed, they would be much better. I'm trying to like them, though
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02-27-2018, 01:01 PM   #4
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I can't tell since these photos are not full resolution, are not 1:1 crops. (I guess forum resizes attachments to some degree).
From the photos, it seems pretty sharp except the bottom left corner. There might be some decentering, though finding an ultrawide lens without decentering is really difficult.
There are threads and a PF post about decentering, you can check those. To test for decentering you probably want to take photos of something near the MFD, so the DoF won't be so wide.

02-27-2018, 01:41 PM   #5
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QuoteOriginally posted by Na Horuk Quote
I can't tell since these photos are not full resolution, are not 1:1 crops. (I guess forum resizes attachments to some degree).
From the photos, it seems pretty sharp except the bottom left corner. There might be some decentering, though finding an ultrawide lens without decentering is really difficult.
There are threads and a PF post about decentering, you can check those. To test for decentering you probably want to take photos of something near the MFD, so the DoF won't be so wide.
Is the trees leaning over typical with an 11 mm lens? I guess an 11 mm calls for a certain type of subject. I have never used anything that wide, and really don't know what to expect, or what type of scene it's good for. I guess I wanted to know if it's a keeper for an 11 mm. I really like the color.
Thanks,
Terry
02-27-2018, 02:32 PM   #6
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The tree distortion can be normal if your lens isn't pointed parallel to the ground. If you are pointed upwards a bit, then it can make things look like they are leaning backwards. If you shoot a skyscraper, this becomes more important (unless you like the distortion) and keeping the lens axis parallel to the ground is the only way to get straight lines in those buildings. Shooting upwards or downwards will show considerable distortion with UWA lenses.

If your tripod or camera (hail the K-1) don't have a level, then a small bubble level can come in handy when setting up for a shot with an UWA.
02-27-2018, 02:34 PM   #7
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The leaning trees are from distortion and while some lenes may handle that better than others it is normal for an ultra wide lens. They will be more noticeable on the edges and extreme corners of the frame, how you frame your shots can either help hide the distortion somewhat or accentuate the distortion for a dramatic effect. There is a learning curve if your not familiar with ultra wide angle lenses.

02-27-2018, 05:17 PM   #8
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I would recommend giving it more time and try a lot of shooting situations, apertures, etc. (unless you are in some kind of return/refund period). Ultra wide lenses are a learning curve as someone else already pointed out. I recently bought a Rokinon 10mm, but I had an ultra-wide back in my film days and knew what to expect. The Rokinon is far superior optically than the UW lenses I was familiar with back in the day and I have heard good things about the Irix lenses.

The slanted lines are normal. You can correct that easily in PS, but there will be some cropping.

If you do change your mind, I can recommend the Samyang/Rokinon 10mm f/2.8 if you still want to try UW.
02-27-2018, 07:00 PM   #9
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Here is an uncorrected and a corrected version of a shot with the 10mm.



02-28-2018, 03:51 AM   #10
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QuoteOriginally posted by bschriver11 Quote
The leaning trees are from distortion and while some lenes may handle that better than others it is normal for an ultra wide lens. They will be more noticeable on the edges and extreme corners of the frame, how you frame your shots can either help hide the distortion somewhat or accentuate the distortion for a dramatic effect. There is a learning curve if your not familiar with ultra wide angle lenses.
Definitely. Distortion is made worse if the camera is not perfectly level. IF there is tilt, rotation, the distortion will appear really unnatural, even unsettling. This is due to distortion, a lens characteristic (but generally it is worse with wider lenses) and perspective itself (again, connected to FoV). UWA lenses are attractive because they are so different from the human eye, but that is a downside, as well. And 11mm is really, really wide, so it will have a steep learning curve.

Edit: Honestly, to people new to UWA I usually recommend Samyang 16mm, because it is really wide, but not awkwardly wide. 14mm, 12mm, 11mm, 10mm... these are extremes and are not easy to master
02-28-2018, 04:15 AM - 1 Like   #11
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I'm with Na Horuk.

11mm on full frame is *extremely* wide. Not an angle of view for the faint hearted Pointing the camera up or down even a few degrees will cause dramatic perspective distortion.

Even at 15mm you have to be very careful. Keep it level you get this:



Point it upwards and you get this

02-28-2018, 11:28 AM   #12
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QuoteOriginally posted by Sandy Hancock Quote
I'm with Na Horuk.

11mm on full frame is *extremely* wide. Not an angle of view for the faint hearted Pointing the camera up or down even a few degrees will cause dramatic perspective distortion.

Even at 15mm you have to be very careful. Keep it level you get this:



Point it upwards and you get this
I definately understand. Those were handheld. I didn't know how important it was to use a tripod. I shot the 15 on a tripod a few days ago, and got much better results. Your pictures are amazing. Unfortunately for me, I live in a city that is 95% farmland. We are famous for peanuts and cotton. I am sending the 11 back, and keeping the 15. I love the 15 fl, and will use it on a tripod with a level. Btw, I have the 3 FA Limited lenses, and love them. But, I need to fill a gap with a 24mm. Is there a 24mm limited that I'm not aware of? Should I consider the DA 15 limited on my F-1? That would get close. Thank you, Sandy.
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02-28-2018, 01:56 PM   #13
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QuoteOriginally posted by KC0PET Quote
Here is an uncorrected and a corrected version of a shot with the 10mm.


Thanks for posting those. I definitely see the difference.
Terry

---------- Post added 02-28-18 at 01:57 PM ----------

QuoteOriginally posted by Na Horuk Quote
Definitely. Distortion is made worse if the camera is not perfectly level. IF there is tilt, rotation, the distortion will appear really unnatural, even unsettling. This is due to distortion, a lens characteristic (but generally it is worse with wider lenses) and perspective itself (again, connected to FoV). UWA lenses are attractive because they are so different from the human eye, but that is a downside, as well. And 11mm is really, really wide, so it will have a steep learning curve.

Edit: Honestly, to people new to UWA I usually recommend Samyang 16mm, because it is really wide, but not awkwardly wide. 14mm, 12mm, 11mm, 10mm... these are extremes and are not easy to master
Thanks for the recommendation.
Terry

---------- Post added 02-28-18 at 01:59 PM ----------

QuoteOriginally posted by KC0PET Quote
I would recommend giving it more time and try a lot of shooting situations, apertures, etc. (unless you are in some kind of return/refund period). Ultra wide lenses are a learning curve as someone else already pointed out. I recently bought a Rokinon 10mm, but I had an ultra-wide back in my film days and knew what to expect. The Rokinon is far superior optically than the UW lenses I was familiar with back in the day and I have heard good things about the Irix lenses.

The slanted lines are normal. You can correct that easily in PS, but there will be some cropping.

If you do change your mind, I can recommend the Samyang/Rokinon 10mm f/2.8 if you still want to try UW.
That's exactly it, I'm within my return time.
Terry
02-28-2018, 02:16 PM   #14
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QuoteOriginally posted by TerryL Quote
I need to fill a gap with a 24mm. Is there a 24mm limited that I'm not aware of? Should I consider the DA 15 limited on my K-1?
No FA24 Limited I'm afraid. I have the FA*24/2.0 which is the fastest 24mm lens Pentax ever made. It's very nice, but a but soft wide open (in a pleasing way) and quite a bit bigger and heavier than the FA Limiteds. I also have 24mm ably covered by my two DFA zooms; the DFA15-30 is at least the match of the FA*24 at that focal length, while the DFA24-70 has a little more barrel distortion but is still excellent.

The DA15 Limited is a glorious little lens - very sharp in the centre, tiny and uniquely flare resistant, but it is notorious for being rather soft at the edges. Most of us happily accept that for its other positives, but I get the impression from your posts that you won't stand for that sort of nonsense
02-28-2018, 02:50 PM   #15
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Na Horuk and Sandy Hancock explained things better than I did and they are spot on.

+1 on the DA15, it is a fine little lens with a few quirks.

Another option to consider is the DA21 f/3.2 Limited. This is one of my favorite lenses.

Edit: Sorry I thought you were shooting a crop sensor, but see you have a K-1. The DA21 is a crop sensor lens as is the Samy 10mm that I mentioned earlier.

Last edited by KC0PET; 02-28-2018 at 03:30 PM.
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