Is the future FF35?

[Tom Lowe]

I don't know anything about astrophotography, so I can't answer that. I would offer the layman's opinion that much of what is regarded as "astrophotography" has migrated to space based platforms - i.e., the Hubble telescope, deep space probes, etc. In those situations, electronic imaging is the only choice because you can't return a piece of physical film to earth electronically. I would also point out that on manned Shuttle missions, there is quite a bit of film shot. In fact, I attended a presentation recently regarding use of the IMAX camera aboard the Hubble "refurbishing" mission last year. It was sent up - at great expense - because it was felt by all involved - including NASA officials - to be the best image capture medium currently available. Not to mention the damage that can be and is done to electronic sensors by cosmic rays in the non-protected space environment, with no currently known method for prevention. However, my entire career has been spent doing "normal" photography, on sets and on location, and in that milieu, what I said is my opinion, which is generally in line with most industry professionals.

I'm talking about Earth-based astrophtography, with 35mm cameras. Nearly all of it is done on digital cameras now. I'm also going to guess that there is no other form of photography that requires as much ability to manipulate image as astrophotography. So you have to ask yourself. If there is more image information on film, why aren't astrophotographers using it?

I'm just posing the question.

BTW, this thread is now miles off track!

Sanjin, let me get some screenshots for you.

[M Most]

Why don't astrophotographers use film? My guess is reciprocity failure. Long exposures can make film response inaccurate/weird etc. Perhaps digital sensors are superior for long exposures.

Good point, I hadn't really considered that.

[Tom Lowe]

Again, though, I want to point out that there are other factors beyond DR. Is Stephen's image going to be as stable and flicker-free as mine? Will his S35 image match the detail and clarity of a FF35 RAW? Doubtful. Let's find out.

[M Most]

Again, though, I want to point out that there are other factors beyond DR. Is Stephen's image going to be as stable and flicker-free as mine? Will his S35 image match the detail and clarity of a FF35 RAW? Doubtful. Let's find out.

From Wikipedia (it can't possibly be wrong if it's in Wikipedia - Wikipedia knows everything...;-)):

Reciprocity failure is an important effect in the field of film-based astrophotography. Deep-sky objects such as galaxies and nebulae are often so faint that they are not visible to the un-aided eye. To make matters worse, many objects' spectra do not line up with the film emulsion's sensitivity curves. Many of these targets are small and require long focal lengths, which can push the focal ratio far above f/5. Combined, these parameters make these targets extremely difficult to capture with film; exposures from 30 minutes to well over an hour are typical. As a typical example, capturing an image of the Andromeda Galaxy at f/4 will take about 30 minutes; to get the same density at f/8 would require an exposure of about 200 minutes.
When a telescope is tracking an object, every minute is difficult; therefore, reciprocity failure is one of the biggest motivations for astronomers to switch to digital imaging. Electronic image sensors have their own limitation at long exposure time and low illuminance levels, not usually referred to as reciprocity failure, namely noise from dark current, but this effect can be controlled by cooling the sensor.

I think that answers your original question.

[Tom Lowe]

MMost, I already conceded from the very first post that film has more DR. No one disputes that.

So getting back to the topic of this thread, is Stephen's S35 timelapse going to be as stable, flicker-free, clear and as full of detail as my FF35 5.6K RAW? Putting DR aside, will his S35 timelapse match the image quality of my FF35 5.6K RAW?

[M Most]

So getting back to the topic of this thread, is Stephen's S35 timelapse going to be as stable, flicker-free, clear and as full of detail as my FF35 5.6K RAW? Putting DR aside, will his S35 timelapse match the image quality of my FF35 5.6K RAW?

Since the FF35 5.6K RAW doesn't exist yet, that's clearly a question that nobody can answer. However, since that 5.6K Bayer chip RAW image will likely represent about 4K of actual resolution once processed - assuming the optics in front of it are capable of passing that - my "quick" answer would probably be yes, based on what current film emulsions are capable of, once again given glass that can yield that. But, once again, this is conjecture because while one currently exists, the other does not. But there are other considerations. Timelapse is a specific case (much like astrophotography) in which certain characteristics of digital imagers have some advantages given certain conditions. One of the nice things about having high quality digital imagers today is that there are choices, and depending upon the specific imaging requirements, there are different tools that are available. It's not just film anymore. Instead of looking at these things as one being consistently superior to the other in every case and in every way, one should be looking at the plethora of tools available and matching their strengths and weaknesses to the requirements of the specific job. What works well for shooting explosions may not be the best choice for time lapse.

[Graeme Nattress]

5.6k is probably heading towards 4.5k measured resolution. Of course, only way to know for sure is to measure. Given that without the OLPF we can induce serious aliasing on the RED One with not the most expensive lens, I'd say that if you're aperture is reasonably set, the 5.6k resolution is probably not yet lens limited. But testing will tell us for sure.

Graeme

[Tom Lowe]

Since the FF35 5.6K RAW doesn't exist yet, that's clearly a question that nobody can answer.

Sure it exists. I shoot it all the time.

Here are two frames shot by Ron Fricke on 65mm film and scanned at 8K for the BARAKA Bluray. The other two were shot by me recently on a FF35mm 5.6K RAW 5D Mark II. These are screengrabs from similar H264 encodings.









Just to be clear, I am not comparing the shots, just the format. Everyone knows that I worship Ron Fricke.

When you watch these shots moving, the digital stuff is far, far more clean, stable, detailed and clear, even against the legendary 65mm, shot by a master.

[David Rasberry]

5.6k is probably heading towards 4.5k measured resolution. Of course, only way to know for sure is to measure. Given that without the OLPF we can induce serious aliasing on the RED One with not the most expensive lens, I'd say that if you're aperture is reasonably set, the 5.6k resolution is probably not yet lens limited. But testing will tell us for sure.

Graeme

One of the features of the new Leica S2 series is that they don't have an optical low pass filter, opting instead for software based variable low pass in the processing. Any opinion on how that might work for RED?

[Graeme Nattress]

One of the features of the new Leica S2 series is that they don't have an optical low pass filter, opting instead for software based variable low pass in the processing. Any opinion on how that might work for RED?

Software OLPF is bollocks, unfortunately. You can, to an extent, deal with chroma moire in software, but luma moire is "burned in" as the point of sampling and if it were easy to seamlessly remove afterwards, we'd all be doing it. Fact is, there's no way to remove it. There is some software that can do a ok guess - Hassy's raw software tries, but when it fails, and it does, it looks ugly. And there's no way it would stand up to motion.

In the end, the "correct" engineering and aesthetical approach is to optically ensure that the input signal to the sensor is sensibly band limited, and that there's enough photosites to get a reasonable degree of oversampling.

Graeme