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Author Topic: Measuring Megabytes  (Read 26298 times)
BernardLanguillier
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« Reply #20 on: May 16, 2006, 06:14:17 PM »
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I've been meaning to bring up this very subject.  How close can you get with a stitched 5D/1Ds2 shot compared to the MF digital backs?

It's certainly not a viable alternative in every circumstance, I am just curious if with the right subject (Horseshoe Bend?) how similar a large print of 30x40" would be.
[a href=\"index.php?act=findpost&pid=65680\"][{POST_SNAPBACK}][/a]

Well, it is difficult to answer in a rigorous way since stitching was not part of this comparison, but my view is that for those subject that allow it, stitching is difficult to beat.

The longer the lens, the higher pixel density you will be able to reach. But using longer lenses has drawbacks like the inability to focus real close, more limited DoF...

In terms of attainable pixel count, the only 4 practical limitations I see for stitching are:

1. The stability of the spherical head as a function of the weight of the body + lens assembly and possibility to use a lens tripod collar to attach the assembly. Because you want to rotate around the entrance pupil point, that point has to be reasonnably close to the tripod collar location for practical reasons. The problem is a possibe loss of sharpness because of vibrations etc...

2. The accuracy of the markings of typical pano heads makes it hard to go beyond 300 mm lenses. Indeed, each portrait image will then cover only about 1.5 lateral degrees, and it becomes difficult to manage the overlap between frames in a reliable way,

3. Lenses in the 200/300 mm range will have too limited a DoF for wide looking images, which limit the interest of simulating a wide angle image by stitching many tele images together. Besides, wide angles images typically work thanks to some sort of near/far composition that is based on a short distance to the subject. This rules out most real tele designs... but not macro lenses like the Nikkor 105 mm VR for instance.

4. Computer resources... but that is not worse than dealing with drum scanned 4*5 files.

All things considered, I don't think that stitching with lenses longer than 300 mm is an option most of the time, and I wouldn't go longer than 50-70 mm for those stitched composition that will "look wide". Even then, reaching 100 MP is often possible with a resulting sharpness per pixel that doesn't look much worse than the P45 samples I saw.

You can of course always stitch using a MFDB as well, but:

- if you need to stitch, then the time it will take to stitch with a DSLR and MFDB won't be that different,
- the Hassy H1 is even heavier that a D2x/1ds2 and its RRS L bracket doesn't look sturdy enough (pure speculation at this stage). The lenses are even heavier still, and most don't have a tripod collar,
- the DSLR 3*2 image ratio results in the pixel density on the long end of the frame being higher than that of MFDB, which speeds up stitching since you will typically be able to shoot less images rows (even if you have more frames per row, that is not the time consuming part),

All things considered, stitching with a DSLR does appear to be the best method today to achieve those very high pixel counts for those subjects when stitching is an option.

Cheers,
Bernard
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BernardLanguillier
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« Reply #21 on: May 16, 2006, 06:22:59 PM »
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You don't think even 3600 US$ is a fortune ?  I'm sure many would disagree....

Photography - in the artistic sense - is rapidly losing grip on economic reality.
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3600 US$ is definitely a lot of money for 90% of the population of this planet, but is in fact reasonnable in photographic terms.

It is for instance about only 2/3 the price of a H1 film lens kit.

If you look at the average income in developping countries, you'll see that 40.000 US$ is clearly above the yearly income just about anywhere. On the other hand anyone willing to sacrifice his/her car for instance (as I have been doing for many years) should be able to spend 4000 US$ on gear a year without huge impact on other spendings.

Regards,
Bernard
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dmcginlay
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« Reply #22 on: May 16, 2006, 07:35:58 PM »
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Wow!

My bennie (Bentley) can out-perform your roller (Rolls Royce)!

Fill in the brackets with your favourite car.

Will I be able to afford one of these top-end systems? Probably not today, but you know my current car has all the features and capabilities of these originals - better know as the trickle down effect; even the cheapest systems, cars, cameras have what has been only available in top end systems previously.

I think this type of comparison is a good idea for various reasons; pure information, pure blast-off comparisons, I am considering buying one of these systems today, etc. - each person has there primary reasons for reading about these reviews.

Keep up the great work.

Satisfied subscriber.
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eyedias
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« Reply #23 on: May 16, 2006, 11:37:22 PM »
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Michael, thanks for publishing these comparisons. I think they are very useful for anyone interested in landscape photography, as I am.

I'm wondering at what dpi the 4x5 Velvia scans were originally made. In landscape photography, digital seems to have a definite cutoff point beyond which enlargements are no longer credible or satisfying, whereas film can be 'pushed' until the grain becomes prominent and still look good, at least to my sensibility.

I wonder, though, how many 4x5 fine art shooters drum scan their images. It would probably be interesting to a lot of people to include a comparison from a lesser, but more common scanner (is that what you left empty spaces for?  ).

I use a Umax Powerlook 3000, which maxes out at 3048 dpi. I think you're familiar with it. A lot of others use the high end Epsons or Microteks. It would be interesting to see the difference between one of these and the P45. At least on the web site, if it's too late for the DVD.
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leonvick
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« Reply #24 on: May 17, 2006, 01:00:21 AM »
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I've ordered the DVD and look forward to running my own tests with it. Meanwhile, I think it's totally awesome that these guys went to the trouble of doing these comparisons and making the results available on the site and on the DVD.

When have we ever seen such a comparison done with top-caliber lenses or films or anything else to this scale, much less with accessible, unmanipulated data from which we can make our own evaluations? I would beg to see more of this kind of thing but the effort required can be so huge that I can only be grateful when it happens.

So thanks fellas. You done good!  
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« Reply #25 on: May 17, 2006, 02:44:52 AM »
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Well, it is difficult to answer in a rigorous way since stitching was not part of this comparison, but my view is that for those subject that allow it, stitching is difficult to beat.

The longer the lens, the higher pixel density you will be able to reach. But using longer lenses has drawbacks like the inability to focus real close, more limited DoF...

In terms of attainable pixel count, the only 4 practical limitations I see for stitching are:

1. The stability of the spherical head as a function of the weight of the body + lens assembly and possibility to use a lens tripod collar to attach the assembly. Because you want to rotate around the entrance pupil point, that point has to be reasonnably close to the tripod collar location for practical reasons. The problem is a possibe loss of sharpness because of vibrations etc...

2. The accuracy of the markings of typical pano heads makes it hard to go beyond 300 mm lenses. Indeed, each portrait image will then cover only about 1.5 lateral degrees, and it becomes difficult to manage the overlap between frames in a reliable way,

3. Lenses in the 200/300 mm range will have too limited a DoF for wide looking images, which limit the interest of simulating a wide angle image by stitching many tele images together. Besides, wide angles images typically work thanks to some sort of near/far composition that is based on a short distance to the subject. This rules out most real tele designs... but not macro lenses like the Nikkor 105 mm VR for instance.

4. Computer resources... but that is not worse than dealing with drum scanned 4*5 files.

All things considered, I don't think that stitching with lenses longer than 300 mm is an option most of the time, and I wouldn't go longer than 50-70 mm for those stitched composition that will "look wide". Even then, reaching 100 MP is often possible with a resulting sharpness per pixel that doesn't look much worse than the P45 samples I saw.

You can of course always stitch using a MFDB as well, but:

- if you need to stitch, then the time it will take to stitch with a DSLR and MFDB won't be that different,
- the Hassy H1 is even heavier that a D2x/1ds2 and its RRS L bracket doesn't look sturdy enough (pure speculation at this stage). The lenses are even heavier still, and most don't have a tripod collar,
- the DSLR 3*2 image ratio results in the pixel density on the long end of the frame being higher than that of MFDB, which speeds up stitching since you will typically be able to shoot less images rows (even if you have more frames per row, that is not the time consuming part),

All things considered, stitching with a DSLR does appear to be the best method today to achieve those very high pixel counts for those subjects when stitching is an option.

Cheers,
Bernard
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I don't know much about MFDB's but on dSLR flat-stitching is easily possible with the shift lenses. I have the shift 24 Canon as my all-purpose wide lens, and I'm told the shift 90 Canon is *excellent*. Whether it's worth the bother I don't know, but certainly the price is right and these lenses seem to have the right properties for flat-stitching. The best trick would be to fix the lens to the tripod and move the camera.

I believe (rumor) that the sharper Schneider shift 28 has distorsion which make flat stitch problematic, and I don't know about the Nikons. Some guys are using russian adapters and MF lenses, maybe they can comment ?

It used to be the alternative was between a digital back and a 1DsII, these days it's between a digital back and a sub$3K 5D, I think for anyone without a big revenue stream exploring these options makes sense. Unfortunately, my clients don't pay for reproduction of a quality sufficient that anything above what I have would matter to them.

Edmund
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John Camp
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« Reply #26 on: May 18, 2006, 11:31:22 AM »
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I thought this test was one of the best things I've ever seen about photography on the internet.

JC
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svein
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« Reply #27 on: May 19, 2006, 01:03:09 AM »
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Ordering the disk - or not.
Regarding Michael's comment on the number of people not ordering the disk after reading the article:
0.2% don't seem too surprising to me. I read the story with great interest and think it really describes "the state of the art". But the price of the equipment used is so far beyond what I can spend that working with the images on the disk just doesn't seem worth the effort. Also, even if I could afford it the size and weight would prevent me from taking advantage of it.
Assume the same applies to a lot of people.
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David Mantripp
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« Reply #28 on: May 19, 2006, 02:52:29 AM »
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Assume the same applies to a lot of people.
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I totally agree. I'm surprised Michael is "fascinated".  I would say 200 is a pretty good score, especially if those 200 are potential customers for the hardware.

Apart from the well-known exceptions, this stuff is just FAR TOO EXPENSIVE for taking photos.

I would add that most of the people who are potential customers probably do not need these files or this report.  They already know what they want, they have PhaseOne reps (etc) on tap, and they're far too busy recouping the cost of their overheads to spend all day on the internet or peeping at pixels.  They just get their assistants to do it.

And now, back on Planet Earth....
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michael
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« Reply #29 on: May 19, 2006, 07:57:21 AM »
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David,

The reason for my "surprise" is the large number of emails that I receive on a constant basis asking how this back or camera compares to that back or camera.

I also get emails from people asking me if I "really' think that medium format backs are that much better than the D2x, 1Ds MKII, or whatever.

I also get a few people asking if they could have a raw file from this or that camera so that they could see for themselves.

I also frequently get criticised when I do product reviews and post image comparisons that I over sharpened, undersharpened, etc, etc, etc.

So, it seemd to me that to be able to get for $10 a disk with carefully produced raw files of the same subject under controlled conditions would be of appeal. Also the fact that the available files include not only some high end backs but also regular equipment in use by pros and others, seemed to me to provide something that would be of interest to a large audience.

Guess I was wrong (Not the first time).

As for the comment, Apart from the well-known exceptions, this stuff is just FAR TOO EXPENSIVE for taking photos, In have to say that this simply expresses a very narrow and parochial perspective.

There are tens of thousands of professional photographers as well as advanced amateurs for whom these aren't Ferraris or status symbols, but are rather the tools of the trade. Many of these photographers frequent this forum, and would be surprised at a comment that denegrates the tools that they use, and their particular needs.

Not everyone is an hobbiest on a budget. Please try and have a more inclusive perspective.

Michael
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Tyler Hawk
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« Reply #30 on: May 19, 2006, 09:48:45 AM »
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It's nice that all that work was put together but it will probably be archaic in two years.  Personally, as it has been said many times before, it's about the pictures.  If you can't take quality shots it doesn't matter how many MP's you throw out there.  

Take the same pic with a 10D and a 5D but give the 10D image to a skilled PS user and the 5D image to an average PS user and both make 11X14 prints on the same printer and I'll just about assure you most people will prefer the 10D image.

This whole MP thing reminds me of all those same guys who got into tizzies about the minutia of lens tests and film grains (same ISO comparisons) and yet couldn't produce a quality image if they fell on it.  Of course they could criticize and out wit the masses on engineering specs and baffle you with that BS.

I can't blame Michael for thinking there was a market for this - it seems a good portion of the posters here are into that and I probably would have made the same business decision.   For me the technology moves so fast that quibbling the difference in some of these DSLR's is pointless.  As for all the backs - if you need it, get it - but do you need it or are you compensating for something  

But again, it's about the pictures - always will be - digital or film.
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benInMA
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« Reply #31 on: May 19, 2006, 02:43:39 PM »
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Every successive test I see like this just re-emphasizes that we have finally gotten to a point where cameras are getting so good that the tools should not be the focus anymore.

Seems like digital created a temporary over-emphasis on the equipment and some of that has got to be fading at this point.

All this gear is so nearly perfect and the pictures are so hard to tell apart, even if I can see the difference if I had bought the RAW files, all the cameras are obviously capable of extremely good results.

I don't know 3 years ago this was definitely not true but today it seems like it's time to stop spending as much time worrying/wondering about equpment and instead start enjoying what you have!
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Fred Ragland
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« Reply #32 on: May 19, 2006, 05:40:17 PM »
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It depends.  I print large.  Incremental improvements in equipment, software and workflow make big differences in large prints.

And it depends on our orientation toward change.  I expect technology to continue producing rapid, significant changes in photography.  As they become available, many of us will incorporate them as welcome improvements, even if they seem incremental (at best) to others.
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David Mantripp
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« Reply #33 on: May 20, 2006, 05:01:00 AM »
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I have to say that this simply expresses a very narrow and parochial perspective.

Not everyone is an hobbiest on a budget. Please try and have a more inclusive perspective.
[a href=\"index.php?act=findpost&pid=66010\"][{POST_SNAPBACK}][/a]

Well Michael you have the right to say what you wish. Maybe in Toronto and California it would be parochial to question if "cost no object" articles are really somehow educational.  I doubt that working professionals who's business justifies these means are your audience, or need your lessons.  Your audience, I thought, was essentially people like me who are just captivated by photography, invest in it all they can (which maybe is not as much as you can afford - so what ?), and would like to learn how to do better. I'm not the only one who thinks you are really in danger of completely losing the plot.

If you want to run a high end site catering to very successful pros and very rich amateurs, go ahead and do it. But make it clear.

Inclusive perspectives apply both ways.  

Whatever. I'm wasting my breath.
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michael
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« Reply #34 on: May 20, 2006, 06:19:13 AM »
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Not to belabor the point, but once again your assumptions are incorrect.

This site is read by a great many professionals. Few have the time (or inclination) to join in forum discussions, but just like any photographer they are interested in the latest tools and techniques. I know this for two reasons. The first, is that I receive large number of emails from them, and the second is that I frequently do seminars that are focused on the needs of professionals, and the turn-out is always high.

In the end, I write about what interests me. For the magazines that I write for I am told what subjects are wanted. On my site, as you rightly point out, I write about anything and everyhting else. This ranges from the $20 Funkycam to high end equipment. This doesn't make this a high-end or a low end site. Hopefully it makes it one that is inclusive of a broad range of interests.

And as for the "Toronto and California" comment, in fact it's just the opposite. It's photographers working in more remote locales that tell me they benefit the most from these pieces, because they don't have retailers and VARs close by, or too many like minded colleagues to share experiences with.

Michael
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madmanchan
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« Reply #35 on: May 20, 2006, 06:21:35 AM »
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Quote from: drm,May 20 2006, 10:01 AM
Your audience, I thought, was essentially people like me who are just captivated by photography[\quote]

Yes, David, but consider the possibility that not every article on this site applies equally to every person who fits the description above.  Some articles cover basic photography technique.  Some articles cover expedition experiences.  And some, like this one, cover equipment, perhaps even high-end equipment.  If you feel the equipment is too expensive and isn't relevant to you, perhaps you ought to skip the article.

I thought Michael's "fascination" comment was appropriate, given the number of people who complain in the forums about invalid comparisons due to improperly or ineptly processed RAW files, etc.  The DVD containing the RAW files is a significant effort to overcome this issue.

Eric
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svein
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« Reply #36 on: May 20, 2006, 10:07:38 AM »
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I wrote the "original" (I think) comment about not being surprised by the lack of interest in the DVD.  I'm still not surprised even after Michael's additional comments about email requests etc.

I'm not a photo pro and don't have a website either, but I've studied and worked with computers since the early eighties. Specially before computer became as common as they are today I got questions about really advanced stuff that the people asking found "kind of interesting", but would never actually spend money on.  Just knowing they are talking to (or mailing) an expert seem to make some people ask all kinds of "advanced" questions. Wont speculate on why.

So, although the price of the DVD was very reasonable it would involve having to do something yourself, including trying to analyze the files better (or at least differently) than four "high-end" photo pros.

A last comment on the article. Although I didn't get the DVD I found the article really interesting. It's these kind of articles that set LL apart from other photosites. That I can't afford it isn't an issue for me at all.
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eyedias
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« Reply #37 on: May 20, 2006, 12:45:08 PM »
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I'm a part-time photographer who (after more than 20 years with 35mm) has just delved into the 4x5 view camera world. Although I'm on a limited budget, I like to keep my eye on the cutting edge. It helps me keep the price of my services fair and gives me a quality target to shoot for.

The comparison by these experienced photographers compares not only digital backs to film, but various lenses as well. Making the raw files available makes it even more valuable for those with high quality standards.

What would make the comparison interesting to an even broader range of artists would be a selection of scans from other scanners. The article teased us with the suggestion that most other scanners would fall below the P45 in resolution, but it would be fascinating to pixel peep that issue too, for me, and I'm sure many others.

If the range of scanners was broad enough, from inexpensive to high-end pro, it would, I'm guessing, have more long term appeal as a kind of guage of where you stand in the capture resolution world. For better or worse, I see an enduring fascination with this question on the forums.

Of course, I would understand completely if Michael says the scope of such a project would distract him from his own pursuits. It's just a idea.
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« Reply #38 on: May 20, 2006, 02:02:23 PM »
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What would make the comparison interesting to an even broader range of artists would be a selection of scans from other scanners.

Check out the following links for scanner compaisons.

http://www.largeformatphotography.info/scan-comparison/

http://www.terrapinphoto.com/jmdavis/

Enjoy!

Mike
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eyedias
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« Reply #39 on: May 20, 2006, 05:03:58 PM »
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Thanks, Mike, for those links. I've sent Leigh Perry a note that I would like my scanner included in his comparison (the largeformatphotography site). What makes it useful is that it uses the same image throughout. The other link uses a dozen different images of hugely varying quality and subject matter, making comparisons difficult. They both leave out digital backs. That's what makes Michael's comparison unique.

So it would still have been interesting to see other scanners added to Michael's comparison. I may still get the CD just to see what a print of a P45 file looks like.

- Victor
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