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Schneider 60XL on 60mpx chip (Credo60/IQ160 etc) samples

tjv

Active member
Hi all,

I've been trying to make do with my Rodenstock 55mm APO Sironar-Digital on my Credo 60 / Linhof Techno platform, making 6x13 panoroamic stitches. It's a good lens on centre but when shifting out to the extremes I regularly do, e.g. 17mm horizontal shift each way, plus often about 6mm rise / fall of the back, the edges turn to mush. From what I gather from inspecting the files, the problem is twofold.

1: Sharpness falloff and
2: Light falloff, which exacerbates noise and detail smearing when applying an LCC.

I know the best option for the sceario is the SK 60mm XL, but I wonder if anyone has some files they might be able to share so I can assess how much better it might be? I'm assuming it's lightyears ahead, but I've learnt to downplay my expectations on gear items that might be considered something of a magic bullet...

For those that use the 60 XL, at the movements I've mentioned how essential is the use of a centre filter for light falloff?
For those familiar with the RS 55 APOSD, would a centre filter do anything to help me save money, of would it simply be a waste of money?

Thanks all,

TJV
 

jagsiva

Active member
I use the CF on mine. It is not necessary, but I do feel it helps with extreme shifts. I shift left/right 20mm, even with some rise/fall without any problems. At 20mm on either side, with the IQ180 I get am at an equivalent sensor size of 95mm x 40mm. I have even gone to +/-25mm without much trouble. The only lens I have that goes more is the SK120 ASPH.
 

Paul2660

Well-known member
I use the CF on mine. It is not necessary, but I do feel it helps with extreme shifts. I shift left/right 20mm, even with some rise/fall without any problems. At 20mm on either side, with the IQ180 I get am at an equivalent sensor size of 95mm x 40mm. I have even gone to +/-25mm without much trouble. The only lens I have that goes more is the SK120 ASPH.
This says it all. Great lens. Huge amount of available shift. I have taken mine to 25mm on the 60mp backs. I use the CF when shifting even small amounts like 15mm. Another great Schneider lens that might grow in value as Schneider has gotten out of this type of lens production.

Paul C
 

vjbelle

Well-known member
As has been stated you can easily shift the amount you want. The main reason for my shifting is to make quick 16X9 formats so I only need 10mm shift left and right..... however I have found that for some, not all, scenes even with this small amount of shift I do need an LCC ( on an IQ180 ). I have never used a center filter with this lens..... you will find that there is some light falloff when shifting that can be handled easily in post. A fabulous lens.......

Victor
 

torger

Active member
I own this lens and use it on H4D-50c. It's really sharp, you can shift far, but it's a symmetrical design and that is when you shift far it behaves like a wide angle lens and you have the color cast and the crosstalk issues to deal with which will at least be measurable on the Credo 60. Most (all?) seem to be happy with it so I don't think you will have any practical issues with it.

Sharpness falloff is visible on extreme shifts, so it's no it's not a magic bullet if you have unrealistic expectations :), but it's the greatest you can get.

I don't use the 60XL as much as I thought I would, the FoV I get on the 49x37mm sensor is rarely suitable for my work. I use the 47 and the 72mm more often. I'm happy each time when it fits though because then I know the sharpness will be exceptional.

I think the 54x41mm sensor size of the Credo60 that makes the FoV a bit wider makes the lens applicable in more situations.
 

tjv

Active member
Thanks all for the informative replies.

I wonder if you'd be able to check out the samples below, which is a two shot 6x13 stictch with the RS 55mm and Credo 60. I've posted here screenshots of the uncorrected LCC shot, the full frame stictch, a 100% centre crop (can't remember exactly where I focused, so approximated,) and a crop from the left of frame. Compared to the 60XL, is this lens a crap shoot?

To recap, the back is shifted 17mm left then right and approximately 6mm rear fall dialed in.
My workflow included LCC with 66% correction for light falloff and Jack's capture sharpening setting of:

Amount: 125
Radius: 0.6
Threshold: 1.0
Luminance NR: 15
Details: 35
Color: 35
Single Pixel: 1

Torger, at what point of shifting does your H50 show crosstalk with the 60XL? I thought that Kodak CCD was essentially crosstalk free with this lens?

Thanks all,

TJV

EDIT NOTE: On my browser these screengrabs are showing up softer oveall than they do within Lightroom CC (where I do final tweaking and stitching.) Not sure how to fix this, but the difference between centre and left of frame is still plainly obvious. Suffice to say that centre is tack sharp, edges are mushy.)




 

torger

Active member
Torger, at what point of shifting does your H50 show crosstalk with the 60XL?
The Kodak CCD has light shields and thus as robust as it gets. It's not a practical problem, I can go to the edge if I'd like. Before LCC with sensitive demosaicers I can see mazing for large shifts which indicates some angle of attack issue, may be some light crosstalk despite the light shields or simply green1/green2 sensitivity difference. The most likely reason is the latter as the problem disappears after LCC. The Kodak CCD has some green channel separation also with perpendicular angle so it's not unlikely that is exaggerated with increased angle.

I don't remember at what amount of shift this happens, but it wouldn't help to judge the Credo 60 performance anyway as it's a majorly different sensor design, it has no light shields, but nearly no green1/green2 separation either.

The angle of view of 60XL is as much as 90 degrees (thanks to large image circle), the 35XL is 102 degrees, lens design is similar. This means that the stress on the sensor at the 120mm edge of the 60XL is similar to that of the 35XL at say 80mm.

I wouldn't be too paranoid about it though. I don't see anyone complaining. When I got the 60XL myself I had heard so much praise though that I was a little bit surprised that it wasn't sharper than it is with high amounts of shift. With moderate shifts it's indeed very sharp though. I'm not too worried about sharpness myself though, I still use the 47XL and is generally happy with its performance despite that it's on a level below.

But your real question is of course if the 60XL will provide a significant improve in image quality over your current 55. It will be better for sure, but if it's of significant value is so very personal, best would be to have test shots so you can decide for yourself.
 

tjv

Active member
Thanks Anders,
Yes, I guess I need to see some samples, which is why I posted here. I'm wondering what people think of the crops I posted above taken with my RS 55mm and how they might compare to the SK 60XL. It seems a waste to resign the such a large part of the edges of the frame to essentially smeared detail, as it's very obvious in my preferred print size of 28" on the short edge.
Thanks again,
TJV
 

Paul2660

Well-known member
Thanks Anders,
Yes, I guess I need to see some samples, which is why I posted here. I'm wondering what people think of the crops I posted above taken with my RS 55mm and how they might compare to the SK 60XL. It seems a waste to resign the such a large part of the edges of the frame to essentially smeared detail, as it's very obvious in my preferred print size of 28" on the short edge.
Thanks again,
TJV
It's a tough call as the 55 HR is no slouch either. The 55mm has always been considered a "very good" lens for the price. From looking at your example, I don't think you would see much gain with the 60XL at 17mm of shift. But at 20mm to 25mm of shift? That is where the 60XL can really go. The 60XL is the only "wide" lens I have that can approach these ranges of shift.

I agree on center to 12mm of shift you can get away with no using the CF, but it does help on larger shifts.

I use the rm3di, so by default I am limited to 15mm of shift. (Personally I hate this and have never understood why Arca did not go to 20mm like Cambo). So for me to get shifts past 15mm, I have to rotate my camera 90 degrees using an L bracket, and add some support under the camera. So I tend to stay in the 15mm range. The 60XL also doesn't have the built in IC indicators that Rodenstock uses, which create the hard vignette when you reach the "edge" of the IC. Another total waste IMO.

So with the 60XL, you can really let go on a big shift. I can't remember the IC on the 55HR, but I am sure it has the IC indicators so eventually on a large shift you will hit them and then have the vignette issue.

the 60XL does not have a great hyperlocal range @ F11 at least from my use. So I also find that I am using tilt on it most times as I prefer the look of edge to edge subject in focus. Just my pref.

Best case would be to try and rent one in your camera mount and see how it stacks up to your 55HR. They will soon be in short supply to 0 as Schneider is done in this market.

Paul C
 

tjv

Active member
Thanks Paul,

That's all good info. I'm wondering if you'd have any samples with approximate movements as you mentioned that you could post crops of?
I'm intrigued that you say you don't think I'd see much gain with the 60XL over the 55mm at 17mm shift. From all other accounts I've read the 60XL is universally praised as being amazingly sharp right out to the edge of the IC. Although I was realistic about what I might be able to expect from the 55mm when shifting that much on the 60mpx chip, the edges are very disappointing in print. At 28x62" the dropoff is very apparent. Digital is so unforgiving compared to film, where the film grain does a good job of hiding optical defects.

In terms of renting one to try out, there's no one in my part of the world that offers such a service. I live in the South Pacific and order everything from Paula at Linhof Studio.

Thanks again,

TJV
 

Paul2660

Well-known member
tjv:

I find that I rarely shift the 60XL past 15mm, due the design on the rm3di limiting me to 15mm on shift in normal capture setup. To get more shift, I have rotate the camera 90 degrees, by use of an L bracket. This leads to other issues, mainly vibration on longer shots since I have taken the camera off center of the tripod. I have a foam block I use under the camera to help, but overall I mainly go to 15mm. If the rm3di allowed 20mm of shift without the hassle of rotation I would do it more.

However I did go back and find a test I did with the 60XL on my IQ160. F11. I can't find my notes from that day, but the shift is around 20mm on right and left. At that time I did not have a CF for the 60XL so the light fall off is pretty bad with this much shift.

What I found, is that the far left and right on the shifted files, is not any better than what you are getting with the 55mm @ 17mm, maybe a bit worse, but some of that may have been my technique. I also had some tilt on so I know that my upper left corner is suffering a bit from that.

The image is fine, and I would still print it it up large, but if you got close, the edges would show some fall off.

I hate to use the word "crosstalk" but no doubt the shifts are suffering from it. You can an area where the green/yellow sat, just starts to fall off on the left most image and on the right my sky suffered. With local adjustments, I can get it back enough of it back to still make a good print, however it's a lot of work for sure. I don't think your 55mm will have as much crosstalk, i.e. loss of sat on these larger shifts due to the retrofocus design. So overall you may have the right lens for the job, and for sure if you go up to the IQ180. I can't remember if you were on 60 or 80MP.

No doubt on this shot, the CF would have helped, as the edges are also a bit noisy.

Paul C
 

tjv

Active member
Thanks Paul, that's really helpful information.

I'm really surprised at your findings about the 60XL, as it's such a highly regarded lens and I assumed it was better out to the edge of the IC than what you've stated. I really wish I could try one to see how much better or how close it is compared to my 55mm Rodenstock, but no one near me sells this stuff, let alone keeps it on the shelf.

What I've found with the 55mm is when shooting scenes like the one I posted above, I can mostly get away with the sharpness falloff. It's when photographing subjects that are more flat, like architecture that I run into serious problems. When I first got my Credo 60 I ran some tests by shooting a mult-story building at work and was quite shocked at how horrendous the edges looked with a 6x13 stitch and 8mm fall of the back. Compared to my 90mm HR W–which was near perfect edge to edge–it looked very funky. I thought hard about maxing out the credit card on the spot for the 60XL, but decided to road test it in the field instead. So far it's proved itself much better in the real world than I thought, but I still get those lingering thoughts. I wonder if the 60XL is better with regards to curvature of field, etc., and maintaing edge contrast and detail on flat subjects.

The other problem I have is that my Techno sliding back only has click stops for horizontal shifts of 17mm in each direction. I'd prefer it if it had both 15mm and 20mm stops, but perhaps I'm the only one who thinks this.

I've also been doing some research into the 70 HR W also and with it it seems I could just get away with doing a 6x13 stitch with 5mm of fall on the back. Considering I much prefer the 70mm focal length for single shot work, I'm wondering if it might just be the better option. It'd be a bit limiting in terms of IC for stitching, but okay for most of what I do. Again, I wish I could try this stuff out!

Thanks again,

Tim
 

tjv

Active member
Thanks JLM, that looks good.
Can you share what settings / movements you employed here? I'm assuming it's a stitch? How do the edges hold up?
Thanks!
 

torger

Active member
If sharpness after shifting is the only thing you need to know, a test with my H4D-50 back will be adequate. It's different sensor technology from the Credo 60, so color cast etc can't be compared, but the pixel size is the same so the pixel peep sharpness should be the same.

I've done such tests before but I haven't kept the images and that time I didn't do LCCs. Due to the thing discussed previously I need to do LCCs for the demosaicing to work well, so the last test wasn't a good one. Before edit of this message I said I'd to a test, but I got a bit lazy but I'll do it if you really want it :). You can send me a private message or email if you want me to test.

My view is that the lens is extremely sharp in the center, but when you shift a lot the reduction in sharpness is like for all other lenses clearly visible. Although it's for sure better than the 55 you have both in center and when shifted, if it's a meaningful improvement will be a very personal decision.
 

tjv

Active member
Thanks Anders,

You're always so helpful with these things. My go to guy for all things Linhof!

I'd really love to see some 60XL samples, thanks. A few days ago I found some of your 72mm and 60mm samples you did a while back–the ones you forgot to do the LCC shots for–but they were a little hard to judge without performing the LCC corrections. If you have time between your many other projects, it'd be great to see a couple more 60XL shots utilising the full 17mm of horizontal shift on the Linhof slider and about 6mm of fall or rise of the back. No rush, just when you have time.

Thanks again,

Tim
 

torger

Active member
I'll try to do it soon. It's bad weather, short days and travelling around that's hindering me a bit :). I'll do both f/16 and f/11. I think you'll prefer f/16 for the large shifts.

I've had a quick peek on my recent real SK60 shots but they're no good performance indicators. I shoot at f/16 these days as I prefer avoiding aliasing more than having supersharp pixels at 1:1, and I haven't had any "brick wall" or infinity type of subjects, almost all my shots are fairly close with focus plane tradeoffs. I also use RawTherapee with quite mild sharpening so the 1:1 look can differ quite much from a default Capture One setting.
 

jlm

Workshop Member
single frame, not cropped, some down tilt (probably 1 degree), no shifting; actually my first shot with the lens
hasseblad CFV-50c, cmos back with the cambo Actus. processed in Phocus, no LCC, no lens corrections, no center filter

it is pretty good on the edges and far/near (tilt). if i was hell bent for edge detail, probably would have done a two shot horizontal pano to make the LS and RS as sharp as possible
 
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