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wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

dougpeterson

Workshop Member
A "correction" of this kind of color cast in Software may result in a visible usable image file, but spoken from a point of lithography view, these files will give a hell of headaches to everybody trying to convert to CMYK -correct and print these in a qualitative way. Of course if you only work for the internet or RGB that may get through somehow, but if I remember right, most of us are still getting their life paid by the printing industry products.

Ask any litho guy, he will tell you the truth about such files.
Stefan,

This statement is completely lacking scale.

It's very simple: CYMK conversion, moderate/severe Photoshop corrections, or large pre-processing adjustments (e.g. pushing shadow detail a stop) require there be reserve dynamic range and tonal smoothness in the file.

Certainly for strong color casts the LCC uses up all of it's reserve dynamic range and tonal smoothness in the correction which means further adjustments (e.g. Photoshop or CYMK conversion, or shadow adjustments) will be straining the quality of the file.

But for minor and moderate color casts, and digital back files shot at Low ISO I would very strongly say your statement is simply not true. The LCC process uses a small amount of the reserve of dynamic range and tonal smoothness in these cases. Further work such as Photoshop, CYMK conversion, or shadow adjustments will still have plenty of meat left.

So I both strongly agree with you, and strongly disagree with you: depending on the scale. One cannot simply paint all color cast in the same light. Severe color cast is a major issue; light color cast is not (as dozens of photographers on this board can tell you from hands on experience).

Given that most back/lens/movement combinations fall into the category of "light color cast" this is a very important distinction.

Kudos however for developing a solution that allows the use of the 17TS/24TS (as well as your own shift optics and a good variety of other lenses) with a digital back. We had a chance to review the Hartblei Cam early in your release/marketing of it and at that point the Canon mount was not ready to ship so we have not had the chance to play with that element. But the build quality and overall functionality of the system was quite impressive.

Doug Peterson (e-mail Me)
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rupho

New member
I shot quite extensively with the 28xl on the P65 and it the lens had much more room for correctable color cast.
My though limited experience using the lens on the IQ180 made me come the conclusion that anything above 5mm on the long side renders the LCC corrected file almost "live less" where the massive blue cast was corrected for. I found extreme noise and loss of saturation.
Woody raised an interesting point: how com that this issue was not reported ( to my knowledge) with the new Aptus.
The only person I know of that owns both backs is Bryan Siebel in Dubai. I wonder if you could chime in if you read this.
It would also be interesting if the IQ160 will have that same effect on color cast.
I personally find the 28XL not usable / reasonably correctable with the IQ displaying such extreme color cast even unshifted is something I have never seen before .
Too bad since I loved the lens before my upgrade which really begs for for an answer: what makes the IQ180 behave so differently compared to the P65?
Just my 2c
 

Terry

New member
what makes the IQ180 behave so differently compared to the P65?
Same sensor size but with 20 million more pixels that are smaller and more tightly packed together has an impact on how the light hitting the sensor behaves.
 

gazwas

Active member
I wonder if(?) the future of MFD turns out to be CMOS, whether those chips will have the same issues as MP's continue to rise as the present CCD's?
 

Terry

New member
Terry, how are you finding your IQ180? I have to live vicariously: no whiff of mine yet!
Very simple and intuitive to use. I seem to use a combo of the touch screen and the buttons (old habits die hard). My fears with the 43XL haven't borne out and the LCC process seems to be really good. I still have a pretty big learning curve with the 180 on the tech camera coming from the P40+ since my focals and framing are different and the DOF is a little different.

Focus mask really does work very well. My 43XL was giving me some focus fits but I worked out the calibration by doing some controlled testing (focus bracketing). I was 99% sure from the camera back masking which whould be the best shots and they were. All LCDs get harder to see in really bright light but the focus mask can't really be missed which is also good news.

Bottom line is I would not trade back.
 

Stefan Steib

Active member
Doug
as of any short answer may lead to misunderstandings - I said "this kind of color cast" - in this context the Schneider samples. We also agree that you can correct "some" colorcast with software getting "usable" files, whereas it is certainly better if there isn´t any. It is also quite important to see that tonal degradation will have a chance to be corrected in High bit(number of available color steps), whereas a strong color cast leads to an overall loss of dynamic range (signal to noise) as can be seen here.

But actually I wonder that there were not stronger reactions to my first posting in this thread, I was nearly sure the Schneider troups would come to rescue the honour of the lens and tell me I am plain wrong......;-)

Greetings from Munich

Stefan
 

Christopher

Active member
Hey,

I wanted to thank Grischa and Yat for meeting me in Hong Kong. I had a great time and was happy that i could help you Grischa, to spend some more money :p

I knew that I would never use the 28mm with movments even before that after I saw a side by side comparsion at Arca Swiss. The color cast is so strong that it blows the channels and so captrure one just can't correct it. One can't correct someting if the data is missing.

I can only say that I am extremly happy with my 32mm, I wanted to get the 28mm, but have to thank Arca and Schneider for telling me it would take 3-4 months longer than the 32mm for delivery. :)

As I am still traveling I don't have the time i would like to have to post more tests and stuff but I will do that as soon as I am back home in july.


A small off topic update. Phase One exchanged my IQ180 before I left and this one certainly is a lot better than the first one. Especially the damaged files are completly gone.
 

Jack

Sr. Administrator
Staff member
But actually I wonder that there were not stronger reactions to my first posting in this thread, I was nearly sure the Schneider troups would come to rescue the honour of the lens and tell me I am plain wrong......;-)

Greetings from Munich

Stefan
Speaking personally as a die-hard Schneider "preferrer," I find it difficult to argue with your original statement -- the 28 is basically not a good match to the IQ180 unless you shoot it un-shifted. So you get no argument from me on your conclusion. Moreover, the first lens I ordered with my tech cam is the Rodenstock 40...
 

Christopher

Active member
Doug

But actually I wonder that there were not stronger reactions to my first posting in this thread, I was nearly sure the Schneider troups would come to rescue the honour of the lens and tell me I am plain wrong......;-)

Greetings from Munich

Stefan
There is none. The lens is great on paper. Small, wide, light, nearly no distorion, but it all fails on the IQ180. It does not help at all, when the color cast is so strong.
 

Christopher

Active member
Speaking personally as a die-hard Schneider "preferrer," I find it difficult to argue with your original statement -- the 28 is basically not a good match to the IQ180 unless you shoot it un-shifted. So you get no argument from me on your conclusion. Moreover, the first lens I ordered with my tech cam is the Rodenstock 40...
Great choice Jack, it is larger than the 43mm, but I am quite sure you will really like the lens.
 

Jack

Sr. Administrator
Staff member
Great choice Jack, it is larger than the 43mm, but I am quite sure you will really like the lens.
Thanks Christopher, but I am a bit concerned over the "more distortion" issue of the 40 compared to the 43...
 

dougpeterson

Workshop Member
Doug
as of any short answer may lead to misunderstandings - I said "this kind of color cast" - in this context the Schneider samples. We also agree that you can correct "some" colorcast with software getting "usable" files, whereas it is certainly better if there isn´t any. It is also quite important to see that tonal degradation will have a chance to be corrected in High bit(number of available color steps), whereas a strong color cast leads to an overall loss of dynamic range (signal to noise) as can be seen here.
Ah, well in that case we are in complete agreement. Color casts as strong as the 28XL and an IQ180 with any shift (and even to some extent the last mm or two of the sides unshifted) is not fully-correctable, and whenever it can be corrected it will leave no reserve at all for further file-abuse.
 

Stefan Steib

Active member
Doug

thank you for your compliments about the camera and lenses, this is a team work, without my partners in Kiev, Venice and Hamburg there would be none of the things we do and I was really lucky to find these guys. We also have to thank for the help of Phase/Mamiya/Leaf, Zeiss, Novoflex and some more, without their support and informations we could not have gone anywhere. Sometimes I am astonished how far we have already moved, if you would have told me 20 years ago we would become the last distributor of Zeiss MF lenses, I would have told you: come on get a nap and get normal.
But it´s fun to play with the big boys ! :)

greetings from Munich
Stefan
 

Jack

Sr. Administrator
Staff member
I don't really think you have to be and there is always the Alpa Lens Cor. which does an amzing job.
Yeah, but I'm running CS 64 bit, not 32, so would need another installation there to run the Alpa corrector -- a hassle factor. Also, how does the Alpa corrector handle shifts?
 

gazwas

Active member
Yeah, but I'm running CS 64 bit, not 32, so would need another installation there to run the Alpa corrector -- a hassle factor. Also, how does the Alpa corrector handle shifts?
Start CS5 in 32bit mode.

"cmd + i" the application icon and check "open in 32-bit mode". No need for another installation.
 
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