Thank you Paul for sending the sample images. I'm not making up a narrative, these are issues that I have seen when using these same lenses on the IQ4. All copies included the center filter that was designed for the lens.
My issue is not with these lenses, it is with exaggerated claims at how perfect they are. If someone believes these claims they will be very disappointed when using them in the field and expecting that they can get 22mm of clean sharp rise with the 35XL or 43XL or anywhere near that with the 28XL.
Here is an example of a RAW image taken with the 28XL with about 12-15mm rise:
View attachment 210404
Here is the LCC
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Here is the LCC after applying processing it in C1
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Here is the image after applying the LCC correction in C1
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The top of the image was completely unusable because the light falloff was too severe for C1 to fix with LCC. I had to crop the image and completely rebuild the sky to get something out of it.
View attachment 210399
Here is the same scene with the GF30TS after automatic lens corrections and minimal exposure/color adjustments were applied in C1
View attachment 210400
Here is the final edited file from the GF30TS
View attachment 210398
Yes. The 28XL, 35XL, and 43XL SK lenses can be fantastic tools for architectural photography, but it comes with a cost. You have to be prepared to deal with issues like I illustrated above. If using a lens with no distortion outweighs all the other associated costs, then you will be happy. If dealing with these types of issues doesn't sound good to you then I would recommend going in a different direction.
Thanks for this post!
A few comments:
I think the point here is that SK glass on BSI is fully and easily correctable to a certain extent that's dependent on the orientation and on a per lens basis to a certain shift amount in mm. Your example above is too much rise for the 28XL in portrait mode on a very wide lens.
My point on the 35 XL was that I think in landscape orientation you can go to somewhere between 12-15 without any issue. If you shoot SK glass at F11 anyway you can make an LCC preset in C1 and literally at that f-stop for typical rise levels both in landscape and portrait mode make LCC plates which then takes a second to invoke once you ingest images. You can even bulk apply them in C1.
So let's say SK28XL_L_F11_R5_L0 for a shot with the SK28 at f11 with 5mm rise in landscape mode. By trial and error you define for yourself which are the best useable increments. On the Alpa you can exchange the shift rails and commission your own custom ones with preset stops (you can still go to any mm, it just nicely clicks into your target stops). All my Alpa cameras have custom shift rails. My STC for example 5,10,15,18.
In the case of the image above I would have just used landscape Rise 10 or 15 and stepped back enough (should be NOT THAT much with a 28 XL!) and then cropped it. Of course if you create these extreme shifts it won't clean up. 22mm rise on 35 XL is also rather extreme. 15 is already very good in landscape and full frame MFD.
I am actually curious to profile a few of my lenses systematically like this. As distortion is fully corrected, its just an important one time thing to do and then selecting from the drop down menu going forward. With Alpa's shift rails you can constrain your shooting to be at 5, 10, 15, 18 rise increments anyhow so 4 presets are sufficient in one orientation. You can of course go fully berserk and do 4 plates centred, 4 plates with 10mm left, 18mm left, 10mm right, 18mm right, etc.
So IMHO the SK lenses are excellent tools. They are extremely compact, weigh next to nothing, can be used with film, on a variety of cameras and backs and, with the right technique are effortless tools. You need to know them inside out though, right, meaning which lens goes to which rise level to fully clean up.
Then you need to use the right technique, ideally in difficult circumstances frame average so noise floor is super low.
The Fuji is heavy and bulky in comparison to SK glass, also costs 4.5k, is not intuitive to stitch and is bound to the Fuji camera. So besides its sharpness and colour cast lessness it has also downsides compared to the tech cam path. Lack of modularity, rectiliniearity are big topics for me, so I am happy to stay in the SK corner.
So IMHO its a question of knowing how to use the tools at your disposal in a smart way and then SK glass is very useable on BSI and the limitations are easily managed by shifting systematically, working with C1's fantastic LCC preset feature and by changing your position or cropping to get the right framing while working within pre-set rise increments. Still, between 5, 10, 15mm rise one should be sble to capture the shot ...
An IQ4 gives you 150 megapixels – stepping a bit back with the 28 XL, keeping it at 15 or 10, cropping, will give you a nice 100 megapixel file in no time.
