Luminous Landscape Forum

Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: qoo3 on December 09, 2006, 09:49:55 am

Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: qoo3 on December 09, 2006, 09:49:55 am
I have just bought Leaf Aptus 75 couple weeks ago and am very happy with its superb image.  

My Aptus75 works on Contax645 body also on ALPA 12TC with C645 adaptor.

Today I made some comparison between C645 Distagon 35/3.5 and Rodenstock 35/4 APO-Sironar digital HR.

I found Rodenstock can create more clear and higher resolution image than Distagon. Especially at the edge and corner.

Maybe C645's lenses are designed for film, not optimized for digital.....  

Rodenstock 35/4, ISO50, F8 (http://www.pbase.com/image/71397740/original.jpg)

C645 D35/3.5, ISO50, F8, mirror locked. On tripod. (http://www.pbase.com/image/71398996/original.jpg)

Corner comparison (left: D35, Right: 35/4 HR ) (http://www.pbase.com/image/71399047/original.jpg)

I also tested Schneider APO-Helvetar 48/5.6.
Although ALPA make it for film usage, I found it still almost have the same performance with digital lens....

Schneider 48/5.6, ISO50, F11 (http://www.pbase.com/image/71398568/original.jpg)
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: TorbenEskerod on December 09, 2006, 11:11:48 am
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Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: TorbenEskerod on December 09, 2006, 11:30:25 am
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Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: qoo3 on December 09, 2006, 01:11:19 pm
Actually, I am not familiar with LC10....
I have no Mac and there is no memu from Leaf. So I can only use try and error to convert the MOS file to TIFF or JPEG format (in PC trial version ).

I also noticed that there are moires. I found there is morie reduction function in LC10. It seems work. Maybe not perfect......But it is enough for me.  

Please see following links

moire reduction_1 (http://www.pbase.com/image/71410473/original.jpg)

moire reduction_2 (http://www.pbase.com/image/71410507/original.jpg)

moire_reduction_3 (http://www.pbase.com/image/71410552/original.jpg)
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: TorbenEskerod on December 09, 2006, 02:02:39 pm
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Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: digitalguy on December 09, 2006, 08:24:29 pm
Quote
It does indeed seems work with the moiré reduction on link 1 and 2 the way you did it - and I can also live with that.

I am much more worried about the color artifacts (CA ?) and how to deal with that - it seems to be everywhere once your eyes are tuned in.

It is still there in your moiré reduction 3 image.

Maybe someone here with more experience can give a hint on how to deal with these artifacts (different backs and different software).

Regarding the Contax 35mm - the one I tested was very sharp also at the corners at F11. In my testing the Hasselblad 35, Contax 35 and Schneider 35 Digitar were almost equal. The Mamiya 35 was not as sharp as the others. All tested on F11, tripod and mirror lock up.

Best

Torben Eskerod
[a href=\"index.php?act=findpost&pid=89583\"][{POST_SNAPBACK}][/a]

I have heard from a rep who works for Phase that at their international sales managment conference a few weeks back they did a simialr test amongst the Mamiya 645 w/ 35mm , H2 w/35mm , not sure about thre contax, but they compared them to a CamboWide with a 35mm Digitar and the results were expected similar to what you have seen.

There is definitly a quality difference between the schneider/rodenstock digital lenses vs the regular lenses from on the 645MF systems.

I have asked for the sample files so they can be posted. It is intersting becuase they also compared H3D w/35mm vs P45 on H2 w/35mm and the P45 image had less CA. The image that was shot with the H3D looked better with their DCA tool turned off.

One of my collegues who just purchased a p45+ was able to take advantage of a worldwide promo that Phase One is doing until the end of the year in which he was able to purchase a Cambo Wide DS w/ 35mm Rodenstock HR lense for $3500 as a bundle with either the P25+ or P45+. Compare that to the list price of a Hasselblad 35mm HC lense at about $3050. He is able to have movements today and a nice piece of glass . No need to wait for that "t/s" lense from hassy that has been talked about for so long and who knows if they will supporrt it with 3rd party backs!
He also had the option of also pre-ordering the new Horseman SWDII Pro, and also if he wanted to could have opted for the 24mm Digitar for a price of $4000.


dg
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: qoo3 on December 10, 2006, 02:27:18 am
Quote
I am much more worried about the color artifacts (CA ?) and how to deal with that - it seems to be everywhere once your eyes are tuned in.

It is still there in your moiré reduction 3 image.

I found the color artifacts in my moire_reduction_3 image is caused by sharpening process. I disable the default sharpening option in LC10 and get much better result....
Maybe we should not sharpen such area in Photoshop.

(http://www.pbase.com/image/71433736/original.jpg)
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: qoo3 on December 10, 2006, 02:31:06 am
Quote
I have heard from a rep who works for Phase that at their international sales managment conference a few weeks back they did a simialr test amongst the Mamiya 645 w/ 35mm , H2 w/35mm , not sure about thre contax, but they compared them to a CamboWide with a 35mm Digitar and the results were expected similar to what you have seen.

There is definitly a quality difference between the schneider/rodenstock digital lenses vs the regular lenses from on the 645MF systems.

I have asked for the sample files so they can be posted. It is intersting becuase they also compared H3D w/35mm vs P45 on H2 w/35mm and the P45 image had less CA. The image that was shot with the H3D looked better with their DCA tool turned off.

Thanks! I wish I can see your sample files to make me more focus on ALPA+Rodenstock/Schneider digital lenses in the future.....
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: BJNY on December 10, 2006, 06:17:11 am
Torben,
Digital capture makes it SO easy to zoom in at 100 percent and inspect.  How does film compare at the same magnification....do you see color artifacts?
Billy
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: TorbenEskerod on December 10, 2006, 09:43:26 am
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Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: eronald on December 10, 2006, 10:04:43 am
The shots above, the "yellow zones" don't look like simple moiré (frequency aliasing) to me - maybe Newton Rings or some interference phenomenon inside the back. I suggest the shots of the building be forwarded to some *experts* at the back company.

Edmund
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: TorbenEskerod on December 10, 2006, 10:09:27 am
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Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: TorbenEskerod on December 10, 2006, 10:18:13 am
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Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: eronald on December 10, 2006, 04:49:46 pm
Quote
Hi Edmund

"yellow zones" ??

If you are refering to this images I posted - the problem is that this moiré shows in every single back I tested (H3D/39, A22 and two A75). And there is no easy way to fix it.

I hope for better luck with P45 next week.

Best

Torben

[attachment=1328:attachment]
[a href=\"index.php?act=findpost&pid=89706\"][{POST_SNAPBACK}][/a]

Yes, what is shown here is clearly frequency aliasing, it's an unavoidable result of digital capture. The only way to avoid it is by blurring slightly at capture eg. by using a so-called low-pass filter, or defocusing the lens slightly. But on the buildings earlier, I thought it might be something else - I was wrong and apologize for a misleading comment. The moiré you see is in no way a defect of the back used.

Edmund
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: qoo3 on December 11, 2006, 09:44:58 am
Quote
I am testing the H3D/39 with 35mm and a H2/P45 35mm next week - It is the same scene as I shot with H2/A75 35mm and Arca/A75 35 Schneider digitar. 

I can mail you some images if you wish.

Best

Torben Eskerod
[a href=\"index.php?act=findpost&pid=89695\"][{POST_SNAPBACK}][/a]
Hi Torben,

Thanks! Please meil me those testing images if you can
my email is: jyc3kimo@yahoo.com.tw

Sincerely
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: made on February 20, 2007, 04:30:50 pm
Quote
Hi Billy

You are absolute right, testing is so much easier with digital and zooming in at 100%, and we all get more and more demanding.

The problem of testing is that the result depends on so many factors - you can get almost any result depending on your postproduction skills.

My problem is not knowing the software LC10 and Flexcolor that well - so I am dependent on the skills of the Reps.

If I had the time to work properly with my test shots I might come to a different conclusion.

I am an Architectural photographer and do demand a lot of my gear.

I don’t see these artifacts and moiré problems when I shoot film.

Maybe my problem is that I might be expecting too much of a MFD Back (in comparison to film and Canon). When I want to put down 40-50K for a MFD system I want the images to be perfect with NO moiré, CA and Color artifacts (unless it is easy to fix in raw development).

Best

Torben Eskerod
[{POST_SNAPBACK}][/a] (http://index.php?act=findpost&pid=89701\")


Hi,

have you solved your problem til now ?

best wishes

Thomas

[a href=\"http://www.koculak.de]My Webpage[/url]
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: John_Black on February 24, 2007, 03:21:10 am
I wonder if a P30 (or P30+) would have the same moire, or less?
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: Danijela D. Karic on February 24, 2007, 03:34:03 am
Quote
I am adding some of my own test:

1: The whole scene

2: Contax 35mm A75

3. Mamiya 35mm A22

4. H3D39 28mm (Sunny day)

I see the same moire / artifacts on all my test.

Please help me to figure out these artifacts (or whatever they are called)

I have asked the Reps from Hasselblad and Leaf to process the images the best possible way in Leaf 10 and Felxcolor (yes CA and lens Correction has been applied).

Best

Torben Eskerod

[attachment=1318:attachment][attachment=1319:attachment][attachment=1320:attachm
ent][attachment=1321:attachment]
[a href=\"index.php?act=findpost&pid=89565\"][{POST_SNAPBACK}][/a]
Hi Torben Eskerod,

I must admit, Nº2 is UGLY. Is there a new firmware for A75 that solves this disaster?

Regards
Danijela
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: fcicconi on February 28, 2007, 10:55:39 am
Quote
Hi Torben Eskerod,

I must admit, Nº2 is UGLY. Is there a new firmware for A75 that solves this disaster?

Regards
Danijela
[a href=\"index.php?act=findpost&pid=102775\"][{POST_SNAPBACK}][/a]
Hi there are not a moire problem but I think chromatic optical aberration.
I made a test with p25 contax 35 1/60 f 9,5 and it's terrible .
I sent to PO support and they told me to change fola lens or diafram or nothing to do.
with A65 too have the same problem.
The lenses are the problem. Sigh!  
I attach my P25 test.[attachment=1945:attachment]
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: Danijela D. Karic on February 28, 2007, 11:40:48 am
Quote
Hi there are not a moire problem but I think chromatic optical aberration.
I made a test with p25 contax 35 1/60 f 9,5 and it's terrible .
I sent to PO support and they told me to change fola lens or diafram or nothing to do.
with A65 too have the same problem.
The lenses are the problem. Sigh!  
I attach my P25 test.[attachment=1945:attachment]
[a href=\"index.php?act=findpost&pid=103766\"][{POST_SNAPBACK}][/a]
I appreciate your response. I wish I didn't have to buy Digital Back, because purchasing Digital Back has proved to be such a waste of time. However, as I said, I will wait after the PMA and then decide.

Thank you

Regards
Danijela
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: godtfred on February 28, 2007, 12:04:33 pm
Quote
I have asked for the sample files so they can be posted. It is intersting becuase they also compared H3D w/35mm vs P45 on H2 w/35mm and the P45 image had less CA. The image that was shot with the H3D looked better with their DCA tool turned off.
[a href=\"index.php?act=findpost&pid=89632\"][{POST_SNAPBACK}][/a]
I think this is weird, as the lens is the same, the chip in the back is the same, and so the software must be the decisive factor (of course the mounting of the chip, and differences between chips could play a part, but one would think that this is negible.)

I think the DAC system in Flexcolor works magic, I'm attatching a shot from the other day (studio) that is downscaled but with a 100% cutout of the upper white mat, you can clearly see the effect of DAC working and the corrected image exibits a clear perfect line between the white and the green.

The distortion correction is easier to see if you load both images in f.ex. preview (mac) and switch back and forth between them...

The camera is an H2, back is CFH-39 and lens is 35mm HC.

-axel

Both images are copyright: Axel Bauer (and may not be used for anything other than viewing in this forum...)

[attachment=1946:attachment]
[attachment=1947:attachment]
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: TorbenEskerod on February 28, 2007, 12:57:39 pm
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Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: Danijela D. Karic on February 28, 2007, 12:59:00 pm
Quote
I think the DAC system in Flexcolor works magic, I'm attatching a shot from the other day (studio) that is downscaled but with a 100% cutout of the upper white mat, you can clearly see the effect of DAC working and the corrected image exibits a clear perfect line between the white and the green.

The distortion correction is easier to see if you load both images in f.ex. preview (mac) and switch back and forth between them...

The camera is an H2, back is CFH-39 and lens is 35mm HC.

-axel

Both images are copyright: Axel Bauer (and may not be used for anything other than viewing in this forum...)

[attachment=1946:attachment]
[attachment=1947:attachment]
[a href=\"index.php?act=findpost&pid=103778\"][{POST_SNAPBACK}][/a]
Hi Axel,

Thank you, I appreciate it very much. I heard that even if correction is applied on HC100mm, it will show the difference, very little but enough to fix.

I compared and switched back and forth between both images in PS, obvious difference. Very nice.

Regards
Danijela
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: godtfred on February 28, 2007, 01:57:12 pm
Quote
Gotfred – the problems I encountered with CA the DCA system in Flexcolor could not solve. I also see your 100% crop is loosing sharpness with the DCA filter.
[a href=\"index.php?act=findpost&pid=103786\"][{POST_SNAPBACK}][/a]
Yep, I see it too now that you mention it, irritating to say the least. I will do some tests with my other focal lengths to see how much it affects those (the distortion correction is much less with the 100, 120 and 210 that I have, so the sharpness loss should be less?)

I don't thinkt it is possible to avoid loss in sharpness though, with the 35 there is quite a lot of pixel shifting/stretching going on to remove the distortion, and this type of shifting would incur a loss in sharpness if you did it using the correction tools available in f.ex. photoshop. Anybody have a take on this, as I'm not sure how one would correct distortion in software without getting some other disadvantage?

Also I wonder if the DAC system would work better if the distortion correction was left off, and only CA correction was used (in the test against Phase One...) The files would be more comparable...

-axel
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: fcicconi on February 28, 2007, 02:09:44 pm
I forgot to say that with contax 80mm there are not this problem.
iìm 95 % happy with my P25 and contax, I would like upgrade to p45 it colud be better.
I think that contax have perfect lenses for film but for digital there are problem.
Are mamiya better?

Rodnstock and schneider are the best but how use  an alpa camera for make portraits?

I asked wich are the best lenses for digital but nobody answered to me.

I wait other tests.
Thank you everybody
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: TorbenEskerod on February 28, 2007, 02:14:19 pm
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Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: TorbenEskerod on February 28, 2007, 02:24:22 pm
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Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: godtfred on February 28, 2007, 02:30:32 pm
Quote
Dont worry too much, I think this is 100% pixl peeping and nothing you will see in print or reproduction.
[a href=\"index.php?act=findpost&pid=103809\"][{POST_SNAPBACK}][/a]
So true. Im very pleased with the files out of my MFDB system, and the prints I get are beyond anything I would have dreamed about a couple of years back    

Quote
Regarding the DCA tool, we did try out different combinations but could not solve my CA problems so I am not really impressed by the Flexcolor CA tool. The distortion tool however is in my opinion a VERY good tool and I am very envious. I do hope that Phase in their new software will have a similar feature.
[a href=\"index.php?act=findpost&pid=103809\"][{POST_SNAPBACK}][/a]
I am on the other hand quite envious of the tilt/shift files you can get with the untethered Phase-One, so you are one function up on me there... the LLC funtion in flex wont work untethered before the next version (I guess that would be 4.6.7.)

Untethered shooting with the ImageBank as a power source on a view camera was a demand from me when I purchased my system, and as LLC is a must when doing this, my dealer wont be happy with my phonecall if it does not appear with the next FlexColor update. (It is said to do so, but one never knows...)

I also heard about P1 coming out with distortion correction from "somewhere other than the web", and hope you dont have to wait too long, it really is a killer feature.

-axel
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: Danijela D. Karic on February 28, 2007, 04:18:22 pm
Quote
Hi Thomas

YES I did solve my problems or rather Phase P45 solved it.   

With P45 NO color artifacts (CA), but still moiré (just a little less).

My last test was together with the Hasselblad Rep (H3D/39) and the Phase Rep (H2/P45) and comparing files together. The Hasselblad Rep was very fair and said: yes I can see the difference in file quality and at this moment we can’t match Phase in your test.

The same lens was used in the test so I think it is not the lens but the back that is the problem – or it could be that Phase has a better software dealing with the problem. I don’t really care as long as it is gone…..

Gotfred – the problems I encountered with CA the DCA system in Flexcolor could not solve. I also see your 100% crop is loosing sharpness with the DCA filter.

I have a very good friend using the Alpa XY and LEAF A75 he does not have CA problems I guess because of Schneider Digital lenses, and his files are amazing (Close to my P45   )

I did not test Sinar backs.

My final choice after testing and testing and testing and ........ was Phase P45, Contax 645 system and Cambo SWD.

Best

Torben
[a href=\"index.php?act=findpost&pid=103786\"][{POST_SNAPBACK}][/a]
Hi Torben E.

Very nice and encouraging thoughts!  

In what respect H3D/39 was not able to match H2/P45 file, was it the file it self or primarily sharpness? What should I pay more attention to?

Regards
Danijela
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: TorbenEskerod on February 28, 2007, 05:18:49 pm
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Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: Danijela D. Karic on February 28, 2007, 05:41:37 pm
Quote
Hi Danijela

Every system has its pros and cons (as you know by now) and in the end I think it comes down to personal preferences - I shoot mostly architecture and therefore have very high expectations to my gear.

Earlier in this thread a while ago I posted some images of the problems I encountered, when you do your own test you should look for similar artifacts (Moiré, CA, Noise etc.). I don’t think sharpness is any issue with any back as long as you use good lenses.

In the end you should trust your gut feeling and go for the system you fall in love with. 

Good luck

Best

T
[a href=\"index.php?act=findpost&pid=103857\"][{POST_SNAPBACK}][/a]
Hi Torben

I totally agree, I just thought there was something you found other then what we have seen previously.

With regards to sharpness, I thought that the sharpness could be the first and obvious difference as it was for me. I found out later, when you open the files in C1 that they get sharpened by a default which I rather like, but anyway it can be turned off if not desired, that's all.

So far I like everything about P45+ except the additional wake-up call cable when used with ALPA and other associated cameras. If I go with Phase, I guess I would have to live with that.

Regards
Danijela
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: TorbenEskerod on March 01, 2007, 03:29:10 am
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Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: vgogolak on March 05, 2007, 11:54:17 am
I must say I am also pleased with the contax lenses. Here is a 80mm 100% crop from a P45
the image in the eye, to rt of the larger highlight, is
ME!   :-)
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: massimodec on January 18, 2008, 02:22:59 pm
Hi to everybody!  
I just have fallen into this post following images with Apo Sironars and I read all your ashtonished posts about the moire effect.

I do not know if in the meanwhile somebody said what I'm going to say.

I have a different idea from you all: I think that it is not the lens, it is not the cable, it is not the software. The moire effect is given by the digital system in its whole.

In my opinion the effect is given by the existence of a GRID in the image (the wall with white bricks) that mixes itself with the grid of the CCD chip.
If the grids are different (as always of course) the black or gray lines of the image collide with the chip's grid creating spaces and lines that have all the mathematical fractioning spaces, that could be measured in Angstrom.
So the effect is raimbow light interference...
Dont forget that the best spectroscope prisms are micro prism thin less that a hair cutted in optical glass, one next another, just like in CCDs.

The only way to avoid colouring and moire, is to use film.

Please, let me know if this topic had other developments; my email decristofaro11@gmail.com
I'm very interested it this subject.
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: massimodec on January 18, 2008, 07:40:32 pm
Thank you.
I know the matter, and I see the first article says exactly what I was saying: the black and white bands image from the lens can mix with the texture of the sensor.

The overlapping of a pattern of lines "almost" squared, as a wall of white bricks, on the perfectly squared pattern of the sensor, creates a series of nouances in  which you can read the magnified image of the grid.

You can see this effect taking two equal grids on a plastic transparent sheet; if you shift them a little apart, you will see the pattern of the "shadows"...

Or the same happens when you acquire a magazine printed image with a scannner.

I think this is an actual limitation of digital photography...
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: Mort54 on January 19, 2008, 12:06:16 am
Quote
I think this is an actual limitation of digital photography...
Moire is an aliasing artefact caused by the regular sampling pattern of digital sensors. This is well understood. All digital signal processing systems sampling on regular intervals are subject to aliasing of one sort or another, so this isn't unexpected, and in fact is taught in undergraduate digital signal processing classes.
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: HarperPhotos on January 19, 2008, 01:47:35 am
Hello,

When I got my Aptus 75 the first thing I experienced when photographing
The All Blacks (a rugby team) that I was getting Moire in there black jerseys.

Since then when I am doing my test shots (polaroids in the old days) if  I see any Moire I use Caprock Anti Moire filters which just slid into my Lee lens shade.

There is a very minable loss of resolution but they reduce the Moire effect dramatically and with a bit more sharpening it doesn't matter.

http://www.caprockdev.com/antimoire.htm (http://www.caprockdev.com/antimoire.htm)

Cheers

Simon
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: rainer_v on January 19, 2008, 08:47:47 am
i have a box of them to sell ...
i used them together with the kodak slr which hasnt had an aa filter and just 14mp. with the 33mp sensor in my field of work it is a rarely appearng issue which i could allways resolve easy ( more or less ) in postpro. with the 22mp sensor it appears more often.
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: massimodec on January 19, 2008, 10:15:06 am
Quote
Moire is an aliasing artefact caused by the regular sampling pattern of digital sensors. This is well understood. All digital signal processing systems sampling on regular intervals are subject to aliasing of one sort or another, so this isn't unexpected, ...
[a href=\"index.php?act=findpost&pid=168097\"][{POST_SNAPBACK}][/a]

This I was thinking, but if you read the previous posts, they are all surprised, and they are blaming the lenses, the cables, etc.
The filter should be a sort of "mixer" that softs edges...
But in architecture textures, patterns and lines of light are the only elements that allow us to see 3D space in a flat image.

I try to avoid digital photography if I can, also for these problems.
But I know that I would not be able to resist so long.

So, now I would like  to pose questions to which I would like also to have answers, because I do not know well:
how is the "gamma" of digital images?
how can we avoid the "interpolation" of color zones that become "medium" color spots?
how good are those digital big and expensive backs for large format?
is enough to make the 3 exposures, oe for each color, to reach a good result?
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: HarperPhotos on January 19, 2008, 04:35:42 pm
Quote
i have a box of them to sell ...
i used them together with the kodak slr which hasnt had an aa filter and just 14mp. with the 33mp sensor in my field of work it is a rarely appearng issue which i could allways resolve easy ( more or less ) in postpro. with the 22mp sensor it appears more often.
[a href=\"index.php?act=findpost&pid=168139\"][{POST_SNAPBACK}][/a]




Hi Rainer,

I to owned a Kodak SLR-n about 3 years ago.

My therapist has told me that that one more session and I should be over the experience.

Cheers

Simon
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: Ron Steinberg on January 23, 2008, 07:03:06 pm
Quote
Hello,

When I got my Aptus 75 the first thing I experienced when photographing
The All Blacks (a rugby team) that I was getting Moire in there black jerseys.

Since then when I am doing my test shots (polaroids in the old days) if  I see any Moire I use Caprock Anti Moire filters which just slid into my Lee lens shade.

There is a very minable loss of resolution but they reduce the Moire effect dramatically and with a bit more sharpening it doesn't matter.

http://www.caprockdev.com/antimoire.htm (http://www.caprockdev.com/antimoire.htm)

Cheers

Simon
[a href=\"index.php?act=findpost&pid=168104\"][{POST_SNAPBACK}][/a]

Simon and Rainer,

Can either one of you post a shot comparing the use of the Caprock filters (with and without), preferably on some sort of fabric? Trying to eliminate some moire in a very difficult situation and would like to know that these expensive filters work before I invest in them.

Thanks!
Ron
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: David WM on January 23, 2008, 08:16:57 pm
Hi Ron

I have just done some tests using a Caprock 5.6 glass 4"sq filter.

I set up a scene where I deliberately found the subject to camera distance which gave me bad moire. I used a H1 with a 120mm macro at F11 and a Sinar eMotion22 DB. Once I had the moire working bad I dropped the filter over the lens to see the difference.
I have attached the result.
No sharpening applied. Processed in Sinar Captureshop, no Moire reduction etc applied. I intended to test the filter, not software.
regards

David


Quote
Simon and Rainer,

Can either one of you post a shot comparing the use of the Caprock filters (with and without), preferably on some sort of fabric? Trying to eliminate some moire in a very difficult situation and would like to know that these expensive filters work before I invest in them.

Thanks!
Ron
[a href=\"index.php?act=findpost&pid=169101\"][{POST_SNAPBACK}][/a]
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: Ron Steinberg on January 23, 2008, 08:22:59 pm
Quote
Hi Ron

I have just done some tests using a Caprock 5.6 glass 4"sq filter.

I set up a scene where I deliberately found the subject to camera distance which gave me bad moire. I used a H1 with a 120mm macro at F11 and a Sinar eMotion22 DB. Once I had the moire working bad I dropped the filter over the lens to see the difference.
I have attached the result.
No sharpening applied. Processed in Sinar Captureshop, no Moire reduction etc applied. I intended to test the filter, not software.
regards

David
[a href=\"index.php?act=findpost&pid=169112\"][{POST_SNAPBACK}][/a]

Hi David,

Your attachments didn't show up, can you try again?

Thanks!
Ron
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: David WM on January 23, 2008, 08:35:37 pm
I couldn't seem to get the attachments to work, so I have put it on my web site here

http://members.iinet.net.au/~imagery/moire/Caprocktest.jpg (http://members.iinet.net.au/~imagery/moire/Caprocktest.jpg)

hope this works
David
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: Ron Steinberg on January 23, 2008, 08:41:56 pm
Quote
I couldn't seem to get the attachments to work, so I have put it on my web site here

http://members.iinet.net.au/~imagery/moire/Caprocktest.jpg (http://members.iinet.net.au/~imagery/moire/Caprocktest.jpg)

hope this works
David
[a href=\"index.php?act=findpost&pid=169119\"][{POST_SNAPBACK}][/a]

Looks like the Caprock filter made things worse?! See left third of middle frame vs. top frame.

Ron
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: David WM on January 23, 2008, 08:51:00 pm
Quote
Looks like the Caprock filter made things worse?! See left third of middle frame vs. top frame.

Ron
[a href=\"index.php?act=findpost&pid=169120\"][{POST_SNAPBACK}][/a]


Sorry, I've mis- labeled them. There was a slight improvement with the filter.

I have reposted the image it is now correct with the unfiltered crop at the top.

David
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: Ron Steinberg on January 23, 2008, 08:57:01 pm
Quote
Sorry, I've mis- labeled them. There was a slight improvement with the filter.

I will re-label and repost the image if you wait a few minutes.
[a href=\"index.php?act=findpost&pid=169123\"][{POST_SNAPBACK}][/a]

In that case the filter did make an improvement, but not overall. Still the left third of the frame  looks much better. To what do you attribute the lack of effectiveness of the filter on the right side of the frame?

Please do let us know if you experiment more with this filter, perhaps on fabrics that do not have as many folds or sheen to them.

Thanks!
Ron
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: David WM on January 23, 2008, 09:07:06 pm
I put the folds in the fabric because I wanted to test the filter with a variety of moires. They seem to happen so randomly. When shooting still life you can try different things like changing magnification, lighting, angle, F stop etc. But the issue which is worst is when shooting people when the moire can pop up at any time as the weave on the fabric of clothes varies so much. I was hoping it might be good enough just to leave the filter on in these situations.

The Caprock filters come in different strengths, which relate to the size of the circles on the filter. The 5.6 is the second strongest (ie second largest circles). I did have the idea that maybe the least powerful filter (smallest circles) may be better suited to these high MP backs (I say high MP because I think they were designed in the days of 6MP dig backs). I would like to try some of the others, but at around $US200 each (once shipped), the results of this test is not encouraging enough at this stage to keep spending.

I don't know why the moire varies.  It just seems to be the way the light catches the weave of the fabric.

I did send the test results to Caprock and asked their opinion, but got no response apart from suggesting opening up wide to get some softening. That is not a very practical suggestion for general shooting.

David
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: HarperPhotos on January 24, 2008, 12:39:50 am
Hi Ron,

Here are some shots taken just this minute.

I have used this shirt as a test for colour moire before to show reps from Leaf and Phase .

Stats:

Mamiya RZ 140mm macro lens

60th sec f11.0  50asa

Leaf Aptus 75

Processed in Adode Bridge CS3

No Sharpening

Image#1: Full frame no filter

Image#2: No filter

Image#3: Caprock filter_4.0

Image#4: Caprock filter_5.6

Image#5: Caprock filter_8.0

I use these filters to remove colour moire when I am shooting fashion or when this affect appears.

Feel free to drag and drop these images and have a go at sharpening them.

Cheers

Simon
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: Ron Steinberg on January 24, 2008, 12:41:53 pm
Thank you David and Simon for posting your sample images, it's been of great help.

Cheers,
Ron
Title: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR
Post by: narikin on January 25, 2008, 11:20:32 am
Quote
Today I made some comparison between C645 Distagon 35/3.5 and Rodenstock 35/4 APO-Sironar digital HR.

I found Rodenstock can create more clear and higher resolution image than Distagon. Especially at the edge and corner.


I haven't read all this thread as its got long, but you really cant compare these lenses - one is retrofocus (for mfSLR) and the other is not.  Its Distagon vs Biogon, and a Biogon is always going to be better as its a purer design.

you have to decide which camera type you prefer/need to use (SLR or viewfinder), and then make the best of it.  end of story.