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Base ISO, long exposure times, and nighttime panoramas

carstenw

Active member
I was doing a test HDR panorama at dusk in a park near my house today, and using the M8 since I haven't got a DB for my Contax 645 yet, and was shocked to find that my longest exposure time was 32 seconds, and I wasn't even really getting the shadows, it wasn't fully dark yet, and this at the M8's base ISO of 160.

The back I am planning to buy is the Sinar eMotion 54 LV, but it has a longest exposure time of 32s, which today would not have been enough. I am now wondering if I have done something wrong, or if there is some way to get around this.

I was shooting three images of each location, in a 360 degree panorama, one at 1s, one at 4s, and I was supposed to shoot one at 32s for the darker areas ( but not the shadows in those areas), but I didn't have a stopwatch nor a cable release, so I settled for 4s at ISO 640, and was hoping that the HDR blend would iron out some of the minor noise this would introduce. This was at f8 with the 28 Cron, at dusk, in a park with a view of the three streets surrounding it, with restaurants and cafés. Annoyingly my battery conked out about 1/2 way through the last pass, so I was never able to complete it, but this was a dry-run anyway, in anticipation of the panorama work I will do soon with the kit I have ordered.

So, given the above information, is there some way I could have worked around the darkness, with a maximum exposure time of 32s? Should I just have accepted the noise resulting from jacking up the ISO to 200 for the last sweep? How do you guys do the long exposures on a camera which doesn't allow setting a speed of slower than 8s (Contax 645)?
 

scatesmd

Workshop Member
Hi Carsten,

This issue came up with me and the M8 at the recent Moab workshop. I tried increasing the ISO, but the noise was too much in the light I had. Ultimately, Guy borrowed Jack's cable release and I timed the shot on the B setting, which worked fine. Others here know far more than I do, but we weren't able to get past 32 sec without the cable release; we couldn't find a setting to bypass the limit.

Thanks, steve
 

carstenw

Active member
So, this would be the same problem with a DB with a 32s max exposure time. My fear is that it wasn't even that dark, and I was already hitting the limit with the M8 at ISO 160. With a DB with 32s max exposure time, and a base ISO of 50, I would have to boost the ISO to 200 to get the exposure at all, and fiddle with the resulting noise. As mentioned, this was at dusk, and I can easily imagine wanting to do exposures at later times.

For those of you with Phase One backs who do city nighttime panoramas, how often do you find yourself doing long exposures? 32s used to seem like a really long time to me, but when doing panoramas, it might be quite easy to hit it, because it is always dark *somewhere*, even if it isn't the main subject of interest.

Which back were you using, by the way?
 

Guy Mancuso

Administrator, Instructor
Bulb , Cable release and say a pray you don't get noise and lot's of it. Most sensors will not handle long exposures and outside the Phase backs maybe a minute is the limit for any 35mm or MF backs. Heat is one reason, dark frames is another. I don't know all the tech reasons but you will be limited and your Sinar back you are planning on is 32 seconds unless something has changed. If this is really important than you need evaluate all your needs here.
 

Jack

Sr. Administrator
Staff member
Carsten:

While the M8 can go longer than 32 seconds by going to B with a cable release, you'll start to see a *bunch* of noise pile up in a hurry. Also yes, all digital backs except the Phase are going to be limited to 30 seconds or one minute, depending on the back. (Though I have heard a rumor that Hassy may be adding a 2 minute setting in the next firmware.) So to answer your basic question, yes that image capture would have been an impossible task with the Sinar back you mentioned...

Now, as to how often I go beyond 30 seconds with my Mamiya... I actually know the answer because 30 seconds is the max limit for exposures on my Mamiya before I have to go to bulb. I shoot landscape and am usually out well before sunrise and well after susnest, and as such find myself going beyond 30 seconds fairly regularly at those times of day. But as a percentage of total images captured, it's going to be fairly low -- a few frames out of every few hundred, so call it 1% of the time. But then the images you get with those longer than 30 second exposures are fairly uncommon too ;)

Here are two recent examples, both from our workshop. The first one is obvious, and a total of 30 minutes:



The next was only around 40 seconds IIRC so in all honesty probably cold have made it work at 30:



Best,
 

carstenw

Active member
Ouch, I was hoping this wasn't the case. I'll have to do more tests and see what I really need here. I was really looking forward to getting the Sinar, with adapters for Contax and Hasselblad V. I don't suppose there is any way to use a Phase back in the same way, switching back and forth?
 

Jack

Sr. Administrator
Staff member
I don't suppose there is any way to use a Phase back in the same way, switching back and forth?
Nope. Easy to do between your main MFSLR body and a tech camera like the Alpa or Cambo as you can swap mounts on them, but not going to be practical swapping between differing MFSLR bodies with a Phase back...
 

carstenw

Active member
Sigh. So, I have the choice of staying with the Sinar, and not being able to some of the HDR panoramas which are part of the reason I wanted to move to MF in the first place, or going with a Phase, and not being able to use my V equipment, which I was also looking forward to. Damned if I do, damned if I don't.

As I understand it, the P-series only has a max exposure time of "several minutes". What does that mean, and how does the IQ at these times compare to the P+ series?
 

Jack

Sr. Administrator
Staff member
But via the appropriate LENS adapter, you CAN use your V glass on the Contax to the exact same image result -- and what's so bad about that?

P non-plus are rated to 60 seconds but you can usually eek 120 or so in cooler weather without hitting a noise issue. However, the plus series can do 60 minutes in moderate temperatures, even more in cooler temps.

It should also be mentioned lest you aren't aware that there is a black-frame subtraction, so any long exposure is effectively doubled for total capture time --- IOW a 30 minute exposure will need an added 30 minutes to process before the camera is ready to fire again...
 

carstenw

Active member
Okay. That is the same as the M8 and other cameras I know, with long exposures, so I am familiar with that. So a P+ back would be the only one which could do what I want. Does anyone know what a used or refurbished P25+ back would set me back at the moment (Contax mount)?
 

Guy Mancuso

Administrator, Instructor
Carsten if you want to use the Contax body it can take a variety of glass I am pretty sure with adapters . Can the Contax do bulb or a T setting. Also on the market right now is a P30 plus for Contax I saw on LL for a decent price. The P30 plus can do a one hour exposure and you can use your V lenses. Plus all those Contax and Hassy lenses are in C1 for there lens corrections. Personally I still think C1 rocks.
 

dougpeterson

Workshop Member
How do you guys do the long exposures on a camera which doesn't allow setting a speed of slower than 8s (Contax 645)?
You can use our Multi-Pop / Long Exposure Device with a Phase One digital back (link) to take longer than 32s exposures on the Contax. You'll need a very heavy duty tripod and diligent workflow to ensure zero movement between exposures (then again, you need such a tripod for most any very long exposure).

Doug Peterson (e-mail Me)
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Jack

Sr. Administrator
Staff member
I know of a P25+ back that *may* be for sale as well, but it is in Mamiya mount. Obviously this would mean you'd need to switch to Mamiya as the main system, but could still use your hassy V glass on it.
 

carstenw

Active member
Guy, I have a V-lens adapter for the Contax, and originally bought the FE110/2 to use this way, but I liked the lens so much that I picked up a 2000FC/M to use with it, for film. I was hoping to somehow also be able to use it with a back, but in the end, I guess it is not such a big deal. Just a bit disappointing.

The Contax 645 has bulb, and a mechanical as well as electronic coupling for cable releases, which is very nice, as it doesn't need battery when used with the mechanical relelase.

Doug, does the multi-pop/long exposure device work with the mechanical release socket? I don't have a heavy-duty tripod yet (I have a Manfrotto 055C and was planning to test it to see how it goes), but I just ordered a BH-55, so I guess the head is covered. I might pick up a Berlebach tripod if the 055C is not good enough. The workflow is something I plan to learn :)

What are some rough current prices for P25+ and P30+ backs, used and refurbished, just to get an idea?
 

carstenw

Active member
Jack, I am quite enamoured with the Contax, and have a waist-level finder for it, which I plan to use for some things. Thanks in any case. Oh, and I don't have the money at this time, but hope to have it saved for later this spring :)
 

carstenw

Active member
Is that your P25+, by the way? I have the feeling from reading your recent posts that you are considering the P45+. Anyway, I understand that Phase doesn't actually change mounts, but gets the back on hand, and waits for one with the correct mount to come in, and then swaps them. I am not sure I would want to wait around for that, as for the less common Contax (in the Phase/Mamiya world) it could take some time. I have heard of people waiting months...

I already have 35mm/3.5, 80mm/2, 120mm/4 Macro, Hartblei 45mm/3.5 and a fun Arsat 30mm/3.5, all in Contax mount, so switching to any other system at this point looks distinctly unattractive. Apart from that, I really like the system.

The 35mm lens is 35mm-equivalent to a 21mm on 645 FF, 25mm on a P25+ and a 28mm on the P30+, all of which seem reasonable for my uses. 25mm is preferable over 28mm, but of course, 31MP is preferable to 22MP. Hmm.
 

carstenw

Active member
Guy, the guy who is selling the P30+ is including a camera kit, and won't sell outside the States in any case. Additionally, I still don't have the money yet :) Once I do, if he didn't sell yet, maybe at that point he is desperate enough to consider a European sale, or maybe I could hop on a plane and pick it up. Anyway, time to save some money.

All this is just me planning ahead, getting the kit together bit by bit. I still probably will need a better tripod, maybe some more pano components for multi-row, and then the back, plus perhaps some cable releases, like the multi-pop or something else (great name, by the way :)).
 
"You can use our Multi-Pop / Long Exposure Device with a Phase One digital back"

Doug,

Have you tried this? I have never been able to use the B setting on my Contax 645 with a P45 because of some error between the electronics in the Contax grip and the P45. 32 seconds on auto is the longest I have ever been able to utilize. Does the multi-pop device counteract this?
 

carstenw

Active member
Argh, more roadblocks! Are there other Contax users here who can chime in about long exposures with Phase P+ backs?
 
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