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Is the IQ180 the end for Schneider lenses ? compared to Rodenstock

Woody Campbell

Workshop Member
I'd be very interested in a straight answer on these issues on an IQ 180 back. I prefer the look and size of Schneiders. I've got a Schneider APO Switar 36mm and an APO Helvatar 48. Both used on my Alpa TC and Alpa Max. I tend to be a wide shooter so these are workhorse lenses for me.

Moderate color shifts are in my view inevitable with these lenses - even shooting unshifted - and are entirely acceptable. The color shifts theoretically change with changes in f-stop and focus but these changes are minor in practice so a single well-made lcc shot for each lens at infinity and the most likely working f-stop is all that is needed (particularly if you're correcting only for color shift - not for vignetting). Corrections can be applied by default in Capture One or Phocus, as the case may be. The "moderate" part of the topic sentence of this paragraph is important - correcting strong color shifts eats up dynamic range and contrast and can result in color channel clipping.

Banding is another issue entirely. It's not acceptable.

So does the IQ 180 exhibit banding (or any other artifacts) in wide tech camera applications, shifted or unshifted? This isn't a tough issue to spot - post an uncorrected lcc image and then an image of it corrected with itself.

My Hasselbald 60meg back is fine unshifted (actually outstanding) with these lenses. But it exhibits centerfolding when shifted with either of these lenses, which is why my Alpa Max is gathering dust, and a major irritant - enough so that I'm considering a move to Phase - but only if the Phase can tolerate 15mm or so of shift in either direction with the 48mm Schneider.

If there is a an IQ 180 owner in NYC PM me - I'd be happy to get together to run a test with my Alpa max.

Kevin and Christopher - thanks - your posts came up while I was writing this. I look forward to samples. I'm particularly interested in the centerfolding issue. With the hasselblad I would describe it as follows. Put the back in portrait orientation and shift on the horizontal axis. With both lenses centerfolding is evident. It's very subtle at small shifts (the 48 is "usable" at 4mm of shift or so) depending on the subject. It becomes more evident at large shifts. It's not evident or is barely visible in the cluttered parts of images, it's painfully evident in blue skies. The Phocus scene correction tool definitively does not correct it. I'll post a sample scene correction image when I get back to my computer in NYC.

BTW I haven't seen any banding with the H 60 back shifted or unshifted.

I'm going to experiment with the following workflow with my H 60 back: Hasselblad native files to DMG in Phocus; Kevin's suggested processing in C1.
 
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gazwas

Active member
I asked questions about banding and CC with tech camera lenses when buying my back a few monhs ago and it fell on deaf ears.

Glad this topic has come up and I can't wait for the IQ/P65 samples.
 

yaya

Active member
I asked questions about banding and CC with tech camera lenses when buying my back a few monhs ago and it fell on deaf ears.

Glad this topic has come up and I can't wait for the IQ/P65 samples.

Gareth this exact topic came up on LL back in March and I've posted samples from the Aptus-II 12 that I've made with the 40mm HR and the 43mm XL

The new C1 6.2 does a good job in handling the banding. In general Rodestock are better in terms of colour cast and you pay for that in distortion, image cicrle and size. They are also sharper at wider apertures albeit with increased falloff

Each of these lenses has an official and a useable image circle and as a user you just have to find the right balance. I use the 43mm XL a lot and as long as I don't push it beyond ~15mm shift (at f8) it works fine. With the 40mm HR you can't really go beyond 11-12mm so again there's a trade-off there

I'm very sensitive to colour casts and can spot it from a mile, I therefore use LCC (or equivalent process) with ALL these lenses.

I have a ton of test images with all the sensors/ lenses/ cameras combinations, pushing them to the extremes and beyond. You can make all of them work as long as you know the limits and how to handle these "effects"

Yair
 

Christopher

Active member
Here we go:

Please don't judge anything general. No editing was done so color can be off. (no WB)

General things:

Schneider 43:
P65 left IQ180 right

0 Rise/Fall


7,5mm Rise/Fall


15mm Rise/Fall


22,5mm Rise/Fall


Now: Full 1:1 small top section from LCC at 7,5mm shift (IQ180 43mm)
uncorrected

corrected
 

Christopher

Active member
As one can see banding is gone and it with little shift it looks great.
However I did not buy a lens with a 120mm circle to only shift 7mm. Here are 1,5cm shift: The banding is once again gone so I won't post it again.
uncrrected/corrected:


While there was't much blue sky, the Sky wasn't that gray. So while the banding is nor problem the huge color cast is.

Other place: IQ180, 1cm rise/fall: Schneider 43 / Rodenstock 40
uncorrected:


corrected:


Rodenstock Dist. uncorrected:

corrected:
 

Christopher

Active member
Centerfold/Banding issue:

Ok, this is a hard one. I take one example, because I don't have to much time.

IQ180 43mm:

A 10mm shift is fine. Just the normal banding and CC

We Problem starts here: Let's say you shoot a tall building and want to have some sky in the shot. So you choose 18mm shift.

Here is what you get:
Full:

Crop



LLC: (larger file 3000xsomething)
http://www.chauser.ch/IQ/IQ180-180-LCC-F.jpg



So there is the problem. The centerfold/banding is so low that it makes the image unusable. Or in other words from now on it is very important to shift only as much as you exactly need. Before that it was easier to make to 15mm shifts and than just to crop of the stuff one doesn't need-


EDIT: Just saw that the second centerfold is the normal one, which can be seen under VERY VERY havy editing. Otherwise it won't be visible. So forget that one. The one on the top can only be seen when shifted.

And here is the same on the P65, however much larger shift. 30mm (banding comes from JPG comp)
 

Christopher

Active member
Personal Problems, or why the back probably will go back to Dealer/Phase One on Monday:

- Corrupted files when saving to CF card. I had this error around 20-30 times while shooting 250 images today. I used quite a few cards ProSpec 8Gb, SanDisk Extreme III and IV with 2-16GB. It only happened sometimes and I couldn't really find a pattern.
- A large color band on the right side of the image. OK LARGE is not really the right word and in most images it would not be seen. I attache here a LCC file with Color boosted to 100

I mean the yelllowish/greenish band. It is on every LLC file I shot with my arca and when the normal file is pushed without LCC it can be seen as well.

Now for a Tech camera it wouldn't be a problem, but I haven't tested it, but would expect it to see it on my Phase 645AF as well. Because it is the same on all lenses.

- corrupted images. This could be a CF card problem, but all of these cards work fine with my P65, 5DMk2, 1DsMk3. First a shot of the problem:


I see this image on the back, so right after shooting it. Mostly it is only going away when turning off the back and removing the battery. I had such a frame or thhe light version (below) around 10-15 times in 250 frames.


For now the END.


I wanted to talk about the 32 and some more stuff, but I first want to get some dinner, get some sleep and talk to my dealer tomorrow, about some of the problems, before testing some more stuff.
 

Christopher

Active member
OK, NOW I have to write more. Because it sounds a little negative. So here more general stuff.

I love the new Display and how it works. I mean I shot with both backs today and really can't imagine going back to a old screen forever. I mean everytime I took the P65 I was thinking, HELL, why can't I see what I just shoot?

It is so much fun to work with the IQ back. Dynamic range is amazing. Especially ISO 35 is really nice. There is so much more great stuff and I would do the upgrade again anytime. Now I just have to figure out some of the problems I'm having.
 

Jack

Sr. Administrator
Staff member
Christopher,

Thank you for taking the time to share these --- very informative and please keep us posted on anything else you learn.
 

dougpeterson

Workshop Member
Thanks for sharing Christopher!

Three thoughts to bring up quickly while on the road...
1) IMO the ONLY meaningful comparison is between the LCC corrected files. If you're going to shoot a tech camera you should be IMO using an LCC on every shot, including on lenses like the 40mm. So what the images look like before LCC is applied is nearly irrelevant. The only purpose of comparing the uncorrected LCC is to gauge what level of the deserve dynic range will be taken up by the LCC algorithm. Guy was kind enough to post a 43mm with the iq180 which was uncorrected which seems to have created undue stress; I could give two hoots whether the lens shows cast or not when unshifted - I care about the real world end result which should IMO always include an LCC. The 24XL on a 45+ shows tremendous color cast unshifted and is still a great lens for that back assuming you are doing the LCC. Even the lenses you think don't have cast unshifted do in fact have shift - just small enough you don't notice it until you do an LCC and see the corrected version.
2) The banding issue scared the crap out of me when I first heard of it and it started popping up with guys like Ed Cooley. I've personally tested the fix in 6.2 with the Aptus-12 (same sensor as iq80) and have confirmed that 6.2 handles banding out to tue edge of the image circle. You can thank leaf for the math as they ha it handled in leaf capture before phase was able to implement it in c1. I'm no longer scared.
3) The 43mmXL has a much larger image circle than the 40mmHR so bear that in mind when comparing the lenses with shift. So even if the iq180 cuts a few mm of useful image circle from the 43xl (which bares testing) compared to say with use of a 45+ then it's still got plenty left compared to the 40hr.

Well that was a lot to type on an iPhone.

Christopher I hope you can comment more on comparing the two lenses AFTER LCC (must be in 6.2 with the wide angle tech camera LCC setting).
 

Terry

New member
Christopher - on the corrected shot of the grey sky where it is clearly darker was your LCC shot with the same parameters as the original shot or did you give it more light? I was told 2 stops More light using the LCC's.
 

Guy Mancuso

Administrator, Instructor
Well I think where the sky is falling on some folks is maybe on the P65 they could do a uncorrected LCC straight shot and it would be fine and with the IQ 180 you may need it on every shot with the 43mm. Lets admit that is more work for some.
But i agree it is part of the life using a tech cam to begin with. Also if it clears out nicely after the LCC corrections who really cares as long as the image is good in final.
 

Jack

Sr. Administrator
Staff member
Christopher - on the corrected shot of the grey sky where it is clearly darker was your LCC shot with the same parameters as the original shot or did you give it more light? I was told 2 stops More light using the LCC's.
Just so everyone is clear, the key to the optimal LCC is using same aperture used as the original capture, and a nice, centered histogram -- be it 2 stops or 4 stops or 1 stop different than the original capture.
 

Christopher

Active member
Ok a few quick notes. I never shot a single frame on a tech camera without a LCC correction.

The 43mm always has quite a strong color shift even on the P65. However, I posted enough which showed that the problem with the IQ180, IS a LOT worse than before. This limits the lens usage. Sure phase one can correct some of it, but not ALL. As seen a both.

I certainly don't want to spend time retouching images just to get the colors right again.

Note to 40vs43, generally you are correct that the 43mm has the larger image circle, but on the IQ180 the color cast gets quickly so strong, that you can't use it. I would say that you get a larger view from the 40 even though the image ciclre is a lot smaller.

I'm also not surprised that nobody commented on the shift/centerfold issue. I know it's there with 32,40,43 and gotten a LOT worse on the IQ180. Looks like one has to check exactly every lens now and how much can be shifted, before using the lens.
 

Christopher

Active member
Christopher - on the corrected shot of the grey sky where it is clearly darker was your LCC shot with the same parameters as the original shot or did you give it more light? I was told 2 stops More light using the LCC's.
No, the normal one was f11 1/60 the LCC was f11 1/15
 

Christopher

Active member
At anyone with a tech camera, or who shot some images with the IQ180 and a tech camera. Is the expsoure shown correct in C1 or on the back? I have only 1/1000 on all shots, which isn't correct ;)
 

Terry

New member
No, the normal one was f11 1/60 the LCC was f11 1/15
Perfect. Thanks for responding.

On the centerfold issue, I'm only shooting a P40+ right now and haven't run into an issue so I guess I don't really understand the centerfold problem and what the root cause is from.
 

GrahamWelland

Subscriber & Workshop Member
Any thoughts on when to use "LCC - Technical Wide Angle" vs normal LCC correction in v6.2 C1 Pro? The wide angle version takes significantly longer although that's not a big issue really in the bigger scheme of things. Is there a rule of thumb as to when it's recommended to use this vs std LCC? i.e. 47mm & wider? shifts > xx mm? etc etc.
 
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