which mfdb for long exposures ? seascape photography

[cooplixphotography]

hello to all, this is my first post ! (altough I'm a long time LL reader)

I'm slowly thinking of buying a mfd back for artwork purposes. I'm a pro photographer, focusing mainly on events, sports, corporate and architecture. Besides those activities, I'm also developing some sort of minimalist long exposure seaside artwork. see http://www.antoinerose.com for a few images. Wether you like or find this kind of photography is not really the scope of this post .
I request your advice for a choice of digital back that would handle this kind of images.  the main issue being the exposure that is often several minutes.
for the moment i'm using a nikon d3x which is quite impressive. A good nef properly developed can be printed on a durst lambda up to 120cmx 120cm.   As I'd like to print bigger and/or print at the same size while retaining more details or being able to crop, i'm looking to mfd backs in the 40mp range. The only one that seems to fit is the phase one p45+. All other backs are not able to go beyond 1 or 2 minutes of exposure.  The pentax 645 d would be an option but the nominal iso (200) is too high for this kind of photo.
is there any other options ? are the new iq backs, or hasselblad or leaf having hidden long exposure mode or "bulb" mode.  The achromatic frome p.one is too limiting for me. i'd love to have an iq160 with the price of a p45+ and more than a minute of exposure time
thanks for your feedback and experience. if you have some long expoure seascape shot on mfb, would be great to see them.

[Weldon Brewster]

You're on the right track with the P45+  I think that's the best bet for the type of work you do.  The only drawback is the P45+ takes an extra black frame (not sure exactly what it is called) that is equal to your original exposure.  A 5 min exposure plus 5 min black frame equals ten mins before you can see an image.  Super clean long exposures though.

[Graham Mitchell]

This is actually an area where film excels compared to digital. A 4x5 camera could produce the results you're looking for, without the huge capital investment. Of the medium format digital options, the P45+ is probably the best long exposure back. Is it not possible to stitch a few long exposures together using the D3X in most cases?

[Richard Man]

I bought a P30 (not the plus) back pretty much for long night exposure purpose. I think the only down side is as someone else has said: the back takes another exposure of the same length to do noise reduction and bad pixel mapping. The longest time I have done is just ~5 mins. Here are a couple samples:

http://www.5pmlight.com/?p=2136 <-- I think ~3.5 mins. I took 3 exposures, trying different ISO to see which one gives the best compromise between IQ and length of exposure. I think this is the ISO400 exposure.

http://www.5pmlight.com/?p=2145 (2nd shot of the SF Palace of Fine arts) <-- ~2 mins exposure.

I think the P30 may have problems with exposure longer than 10 mins or so, but I don't intend to do that kind of photography so it's OK with me.

[Murray Fredericks]

I agree with Graham,

This is about the one place film amy be a better option...

Cheers

Murray

[cooplixphotography]

I agree with the fact that film may be the best option, however not for me.
the size of a 4x5 view cam + the hassle of scanning, the time needed to go back and forth to a decent lab, is a blocking factor for me.
I have a pentax 67ii that sits in its bag since 2 years. My D3x is just so great to use, add a pc-e nikkor 24mm and you have a nice combo. Not to compare with alpa + rodenstock + back but not the same price.

for the stitching suggestion, i never tried. I'm not sure the result would be great with longer exposures. (moving clouds) but in some case it might be an option. Any recommendation on a good stitchi g tool ? I thing photoshop cs 5 has a built in tool for panorama but never tried.

Regarding the dark frame, can you disable it ? Is it really needed ? I have the same option on my nikon but never use it. in black and for the kind of photography i do, it is not mandatory.

A refurb phaseone + p45+ costs 13k eur in europe. the pentax at 9000 usd is also an interesting option except the native iso which is 200. It's a lot of money, I therfore need to carefully assess the different possibilities.

[TH_Alpa]

Yes, the dark reference file or dark calibration is necessary. If you don't apply this file to the image, it will show extrem noise.The dark file is shot at the same shooting time to get the resulting noise and then substract it from the image file itself.
I don't think one can disable this on any of the current available DBs, in fact am quite sure.

Thierry

Regarding the dark frame, can you disable it ? Is it really needed ? I have the same option on my nikon but never use it. in black and for the kind of photography i do, it is not mandatory.

[Murray Fredericks]

If Film is not an option then really one of the Phase Backs p45+ (or back with similar sensor) are you only choices. You should test though.  Some subjects will look fine at this time and others will not. While the long exposures are possible, there are various compensations made in the back to handle the noise and this will affect the overall image quality.

Generally a few minutes will be fine with most subjects.

m

[Doug Peterson]

4x5 film has some advantages and disadvantages for long exposures in the 5-10 minute range.

+/- Reciprocity failure leads to longer exposures than anticipated (actually somewhat of an advantage for the OP's specific needs but generally a negative)
- Reciprocity failure leads to color shifts in some/many emulsions (not a problem if you pick your emulsion appropriately or accurately counteract the shift)
+ It has no dark-calibration requirement
+ It has no hard exposure limit (other than decreasing sensitivity due to reciprocity)
- Dim scenes are hard to focus (bringing a flashlight and a stand to hold it if practical)
- Contrasty night scenes (the OP's scenes are not, but others are) are hard to calculate exposure for and you'll have no confirmation like you do with digital
- very dim scenes are hard to compose on gg, again no digital confirmation of framing
- The format requires you stop down roughly two stops more to gain the same DOF as a medium format back*
- The larger camera is more of a "sail in the wind" where there is wind meaning even with steady tripod a 5 min exposure is hard to get sharp
- Big/heavy to carry around (no problem for some, deal breaker for others)
- For color: Harder and harder to find places that not only process 4x5 color film but that are good at it and with whom you won't risk losing images because of their incompetence or issues due to low volume.
- For B+W: you must select your tonal sensitivities (red filter, yellow filter etc) in advance, you must process your own film or find a good lab you trust with your hours/days of travel/work**

*Now in this case the OP is asking about achieving a set length of time to smooth out the ocean. So the disadvantage of requiring a higher f-stop to get the same DOF is largely moot.
**I enjoyed B+W film processing - so obviously this one will be personal
**

---------------------------
Now onto medium format digital which based on where the user is coming from I strongly suspect he will be using:

http://www.captureintegration.com/phase-one/phase-one-tech-specs/

Note that most of the non plus backs are NOT rated for several minutes. The P45 non plus is rated for several minutes. Now a back's rating is only applicable for:
- room temperature
- processing in native software (LR will not do as good for long exposures)
- a particular person/companies' definition of "usable"

Regarding temperature: check out the chart of temperature vs. exposure length on the link I sent you. This means one user who uses the back in the cold winter morning and a user who shoots in a hot desert just after sunset will have RADICALLY different opinions on what the longest usable exposure of a given back is.

Regarding the definition of "usable": as you expose longer and longer (depending on the kind of sensor) you'll notice (roughly in order):
- loss of shadow color accuracy
- stuck/hot pixels
- increased luminance noise
- loss of shadow detail
- overall color issues
- strong color issues
- loss of contrast and tonal smoothness

Loss of shadow color accuracy isn't meaningless in B+W since your conversion still counts on determining tone based on the original color, but it's also not a deal-killer. Single stuck/hot pixels are pretty easy for software to remove; at some point as they become excessive you lose detail and fine texture, but for your smooth seascapes that's also maybe not a deal killer.

So you might be able to use a back for a bit longer than the stated manufacturer spec (and longer than other people who shoot e.g. color commercial work with lots of critical fine detail. But of course it's best if your work doesn't take your back to the absolute limits of it's capabilities.

Note that the 65+ is NOT a long exposure back (see our link again). It's spec'd for 60 seconds max.

So on net it's really hard to suggest anything other than a P45+. This back will not flinch at any of the exposures you're talking about; producing images at many minutes with great color and great detail and very high resolution with minimal effort. You'd never be limited by your gear (which is a terrible feeling IMO - especially if it's 2am and you've just walked a half mile in the dark to set up an image).

Doug Peterson (e-mail Me)
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[KevinA]

This is actually an area where film excels compared to digital. A 4x5 camera could produce the results you're looking for, without the huge capital investment. Of the medium format digital options, the P45+ is probably the best long exposure back. Is it not possible to stitch a few long exposures together using the D3X in most cases?

I would second that and if you are happy with one lens and no movements something like the Razzledog folding 5x4 would be ideal http://homepages.ihug.com.au/~razzle/

Kevin.

[mtomalty]

"Yes, the dark reference file or dark calibration is necessary. If you don't apply this file to the image, it will show extrem noise.The dark file is shot at the same shooting time to get the resulting noise and then substract it from the image file itself."

Would it be possible, with current technologies and manufacturer willingness, to have the dark frame exposure captured,stored, and applied in the way  that LCC corrections are applied within Cap One ?

As an example, if i know I routinely expose a certain type of image for 15 minutes would it not be possible to have an archive of black frames subtraction frames to apply as I do with LCC corrections?
Obviously, there would be some variance due to ambient temperatures and other influences but to be able to disable the black frame exposure at the time of capture could make the
shoot more productive in these conditions


Mark
www.marktomalty.com

[Bart_van_der_Wolf]

Would it be possible, with current technologies and manufacturer willingness, to have the dark frame exposure captured,stored, and applied in the way  that LCC corrections are applied within Cap One ?

Hi Mark,

That would be most welcome. In addition it would allow to improve the quality of long exposures by allowing to use the average of multiple darkframes. By subtracting a single darkframe one can reduce the systematic noise which is more or less repeatable and could even exhibit a pattern. Unfortunately it also increases the non-systematic read noise, upon subtraction. By averaging multiple darkframes the readnoise gets eliminated (it averages out to zero SD). The resulting average of the darkframe could be called a Darkframe master, and be reused given similar temperature and exposure time conditions.

As an example, if i know I routinely expose a certain type of image for 15 minutes would it not be possible to have an archive of black frames subtraction frames to apply as I do with LCC corrections?
Obviously, there would be some variance due to ambient temperatures and other influences but to be able to disable the black frame exposure at the time of capture could make the
shoot more productive in these conditions

Indeed, it would allow to speed up the image taking by reducing the interval between long exposures, and one could average multiple long exposures as well to improve on the shotnoise and ISO gain noise effects.

So, image averaging and Darkframe subtraction would be welcome additions to Capture One or similar Raw converters.

Cheers,
Bart

[Sussex Landscapes]

If you where thinking of the Pentax and you are limited to base iso of 200, why not get a 1 - 2 stop nd filter? or have i missed something?

[julienlanoo]

I must follow the P45+ line,
or any phase one that has a + signe... ( as in Sensor Plus technologie)
( i love the P45+)


Do not use Leaf for long exposures, this, not because it's a bad back, ( i've also got a leaf a valeo, for product & skin and some web stuff ),
Simply because, it's strong point is it's weakness at long exposures... the ventilator, that makes micro vibrations...

My P45+ becomes quite HOT when doing realy long expousers, no stress apparently it's normal, only don't make 5 in row, i don't know if it would do some thing to the back but i try to save it a bit some times...

[TH_Alpa]

Bart

Would such not be very difficult to implement? It would mean to have such average dark files for different exposures times x by different temperatures, since the resulting noise is highly dependent on the temperature? In addition to that, the temperature of the back, resp. the sensor (different, depending how many times in a raw one takes frames) would also change the noise.

That would be many variables to take in account and many files to have at hand and saved, isn't it?

Best regards
Thierry

That would be most welcome.
Indeed, it would allow to speed up the image taking by reducing the interval between long exposures, and one could average multiple long exposures as well to improve on the shotnoise and ISO gain noise effects.

Bart

[Bart_van_der_Wolf]

Bart

Would such not be very difficult to implement? It would mean to have such average dark files for different exposures times x by different temperatures, since the resulting noise is highly dependent on the temperature? In addition to that, the temperature of the back, resp. the sensor (different, depending how many times in a raw one takes frames) would also change the noise.

That would be many variables to take in account and many files to have at hand and saved, isn't it?

Hi Thierry,

You are correct that for a technically perfect operation there are many variables that play a role. However, there is always an option to not get it perfect but good enough, and certainly much better than without it.

What I'm hinting at is that while the dark noise is (besides time) dependent on temperature (mostly inside the camera), it does not continue to rise with exposure time. The camera will sooner or later reach a temperature equilibrium (at a given outside temperature and a given cooling scenario).  Besides, the dilemma is also there with a single darkframe. When the darkframe 'exposure' is taken following the actual exposure, then the camera is probably a fraction hotter than at the actual exposure.

In addition, successful results have been produced by interpolating between the 'master darkframes' of different exposure times, but for that there first needs to be darkframe averaging to reduce the random noise of a single darkframe. What remains is hot pixels and pattern noise caused by the so-called dark-count, and read noise from a 'hotter than usual' sensor, without the randomness of a single darkframe. Since the overall generation of the 'dark count' is very predictable along the time scale, it can be utilized for calculating intermediate exposure times. It probably won't be exact, but it will be quite usable.

These principles are being used on a daily basis by those who practice astrophotography, and they achieve 'stellar' results (pun intended).

Besides, a capability to average multiple exposures will also reduce the noise in shorter exposure times. Photoshop Extended offers that capability for already Raw converted files, but the benefit will be even higher when employed on the Raw data before demosaicing, the Raw conversion will be more accurate. That's why such an exposure averaging feature would be so useful to add to Capture One or other Raw converters. We will be faced with similar challenges of stability and stationary subjects as on a multishot sensor, but when executed well the results cannot be beaten. Dark frames can not suffer from subject or camera movement, so they are a relatively simple subject to average.

Cheers,
Bart

[TH_Alpa]

Thanks Bart, for your precise and enlightened answer.

Cheers too
Thierry

You are correct that for a technically perfect operation there are many variables that play a role. ... probably won't be exact, but it will be quite usable.
Bart

[SeanBK]

Try renting a Phase back & a Hassey back just for a day. take sample shots, then decide. That's what I'd do for a specific solution & a major investment.

[cooplixphotography]

If you where thinking of the Pentax and you are limited to base iso of 200, why not get a 1 - 2 stop nd filter? or have i missed something?

hello,
I'm often shooting when the luminosity is still high. I don't wake up t 2am in the morning to take pics. Therefore, I'm using a b&w nd1000 which is fine when the clouds are moving quickly and the water is choppy.
Sometimes a nd1000 is not enough shooting at a base iso (100 for my d3x). In this case, having 50 iso native is an advantage, while 200 iso is a disadvantage in this specific case. I tried once to stack a nd1000 with an additionnal 2 or 3 stops filters but the results were sub-par. I try to stick to a nd400 or nd1000 (bw or hoya) + nd grad from lee filts. by the way, anybody tried the Lee big stopper ? how does it compare to bw nd1000 ?

[DanielStone]

OP: Are you able to set up your photographs during the day/early evening? This way, you'd have more light to accurately compose/frame your photograph.

A Toyo 45A/II, or a Technika IV/V w/ 1-2 lenses can be a very versatile, "lightweight", super high quality option. Just FYI, a friend just purchased a Toyo 45AII, with 3 modern Rodenstock lenses for under $1500. He got a 90mm Grandagon(superb WA), 150mm APO-Sironar S, and a 210mm APO-Sironar S. Combine this with a lighter aluminum tripod from Gitzo or Manfrotto, maybe with a 10lb sandbag(like a "Boa" bag, steel shot rather than sand, so its smaller size-wise), and you've got a very steady platform for shooting from.

-If you want to shoot color only, then I'd go with Provia 100F.
-Black and white film: Fuji Acros 100(or Tmax 100). Acros/Provia have virtually ZERO reciprocity failure out to around 20min or so from my "field tests".

-Get the film processed by Samy's in Santa Barbara(E-6 is $1.70/sheet for 4x5, can't remember B+W pricing). I use their services for 4x5 and 8x10 E-6/C-41, and I've never had a problem with them. They happily do mail order, that's how I send to them.

-Scanning(if you're in the USA): You have LOTS of options for people. James Beck  http://www.jamesbeckdigital.com/jbdscans/drumscan.html  , Lenny Eiger  http://www.eigerphoto.com/services_technology_ep.php, and many other independent people offer super high-quality drum scans. I mention the above two, since I've used both of them for scans, and have ALWAYS been very happy with their services.

Lastly, I've found that when shooting with the larger view-camera, I tend to be more "choosy" with my photographs taken. I can shoot digital if I want(5d II), but I find myself using my 8x10, 4x5, or sometimes the Hassy kit to shoot long(ish) exposures.

To me, the whole P1 "dark frame" can be limiting, especially if you have 5min+ exposure times, and would like to photograph multiple angles(or scenes) in a single evening. To me, this is more limiting than hefting another 15lbs of kit from the car into the field, or loading up some film holders in the darkened bathroom before heading out. Just sayin

-Dan