Ad
Ad
Ad
Pages: « 1 [2] 3 »   Bottom of Page
Print
Author Topic: C645+D35/3.5 vs ALPA+Rodenstock 35/4 HR  (Read 22281 times)
godtfred
Sr. Member
****
Offline Offline

Posts: 293



WWW
« Reply #20 on: February 28, 2007, 11:04:33 AM »
ReplyReply

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]
« Last Edit: February 28, 2007, 11:55:24 AM by godtfred » Logged

Axel Bauer
godtfred.com
H2|M679CS|P45+
TorbenEskerod
Jr. Member
**
Offline Offline

Posts: 76


« Reply #21 on: February 28, 2007, 11:57:39 AM »
ReplyReply

xx
« Last Edit: January 20, 2008, 05:39:22 AM by TorbenEskerod » Logged
Danijela D. Karic
Full Member
***
Offline Offline

Posts: 221


« Reply #22 on: February 28, 2007, 11:59:00 AM »
ReplyReply

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
Logged
godtfred
Sr. Member
****
Offline Offline

Posts: 293



WWW
« Reply #23 on: February 28, 2007, 12:57:12 PM »
ReplyReply

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
« Last Edit: February 28, 2007, 12:58:34 PM by godtfred » Logged

Axel Bauer
godtfred.com
H2|M679CS|P45+
fcicconi
Newbie
*
Offline Offline

Posts: 41


WWW
« Reply #24 on: February 28, 2007, 01:09:44 PM »
ReplyReply

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
Logged
TorbenEskerod
Jr. Member
**
Offline Offline

Posts: 76


« Reply #25 on: February 28, 2007, 01:14:19 PM »
ReplyReply

xx
« Last Edit: January 20, 2008, 05:39:37 AM by TorbenEskerod » Logged
TorbenEskerod
Jr. Member
**
Offline Offline

Posts: 76


« Reply #26 on: February 28, 2007, 01:24:22 PM »
ReplyReply

xx
« Last Edit: January 20, 2008, 05:39:51 AM by TorbenEskerod » Logged
godtfred
Sr. Member
****
Offline Offline

Posts: 293



WWW
« Reply #27 on: February 28, 2007, 01:30:32 PM »
ReplyReply

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
Logged

Axel Bauer
godtfred.com
H2|M679CS|P45+
Danijela D. Karic
Full Member
***
Offline Offline

Posts: 221


« Reply #28 on: February 28, 2007, 03:18:22 PM »
ReplyReply

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
Logged
TorbenEskerod
Jr. Member
**
Offline Offline

Posts: 76


« Reply #29 on: February 28, 2007, 04:18:49 PM »
ReplyReply

xx
« Last Edit: January 20, 2008, 05:40:05 AM by TorbenEskerod » Logged
Danijela D. Karic
Full Member
***
Offline Offline

Posts: 221


« Reply #30 on: February 28, 2007, 04:41:37 PM »
ReplyReply

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
Logged
TorbenEskerod
Jr. Member
**
Offline Offline

Posts: 76


« Reply #31 on: March 01, 2007, 02:29:10 AM »
ReplyReply

xx
« Last Edit: January 20, 2008, 05:40:18 AM by TorbenEskerod » Logged
vgogolak
Sr. Member
****
Offline Offline

Posts: 337


WWW
« Reply #32 on: March 05, 2007, 10:54:17 AM »
ReplyReply

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!   :-)
Logged
massimodec
Newbie
*
Offline Offline

Posts: 3


« Reply #33 on: January 18, 2008, 01:22:59 PM »
ReplyReply

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.
Logged
jsch
Sr. Member
****
Offline Offline

Posts: 423


« Reply #34 on: January 18, 2008, 06:21:21 PM »
ReplyReply

Hello,

2 years ago I attended a talk by the former CTO of Schneider lenses, Dr. Karl Lenardt. He covered these things. There is an article where you can read all of that - I admit it is a bit technical and you have to wrap your brain around it. But it's worth it:

http://www.schneiderkreuznach.com/knowhow/digfoto_e.htm

Sorry, I forgot this one:

http://www.schneiderkreuznach.com/knowhow/opt_quali_e.htm

Best,
Johannes
« Last Edit: January 18, 2008, 06:24:58 PM by jsch » Logged
massimodec
Newbie
*
Offline Offline

Posts: 3


« Reply #35 on: January 18, 2008, 06:40:32 PM »
ReplyReply

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...
Logged
Mort54
Sr. Member
****
Offline Offline

Posts: 590


WWW
« Reply #36 on: January 18, 2008, 11:06:16 PM »
ReplyReply

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.
« Last Edit: January 18, 2008, 11:13:16 PM by Mort54 » Logged

I Reject Your Reality And Substitute My Own
HarperPhotos
Sr. Member
****
Offline Offline

Posts: 1242



WWW
« Reply #37 on: January 19, 2008, 12:47:35 AM »
ReplyReply

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

Cheers

Simon
« Last Edit: January 19, 2008, 02:33:36 AM by HarperPhotos » Logged

Simon Harper
Harper Photographics Ltd
http://www.harperphoto.com
http://www.facebook.com/harper.photographics

Auckland, New Zealand
rainer_v
Sr. Member
****
Offline Offline

Posts: 1130


WWW
« Reply #38 on: January 19, 2008, 07:47:47 AM »
ReplyReply

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.
« Last Edit: January 19, 2008, 07:49:24 AM by rainer_v » Logged

rainer viertlböck
architecture photographer
munich / germany

www.tangential.de
massimodec
Newbie
*
Offline Offline

Posts: 3


« Reply #39 on: January 19, 2008, 09:15:06 AM »
ReplyReply

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?
Logged
Pages: « 1 [2] 3 »   Top of Page
Print
Jump to:  

Ad
Ad
Ad