Used Backs: How Many Captures is Too Many?

[Juanito]

So my Leaf Aptus 22 sensor is on its way out and I need to replace it. I'm looking at the various used backs that are available on the market but, in purchasing one, I don't want to find myself back where I am now. So how many captures constitutes high use on a digital back? At what point does the likelihood of sensor failure start to increase? I'm looking at Leaf since I'm happy with my previous back but curious if there's a difference between backs.

Thanks,

John

[Peter Devos]

hi, as there are no moving parts in a back, (only the fan wich is not that expensive) i really think the actuations are of no importance. I really trust more a back that ran 25000 shots than one that only had 500 shots taken in 2 years or so. I have most backs seen failing always in the beginning of the purchase. I think 150000 shots is a good average to sell a back :-)

[John R Smith]

So my Leaf Aptus 22 sensor is on its way out and I need to replace it.

What is wrong with your Aptus 22 - are you sure it is a sensor fault (rather than ADC, circuit boards, etc). And have you had a quote for repair?

John

[Gary Ferguson]

I seem to recall Phase One running a test rig that automatically fired exposure after exposure, after running night and day for months they'd achieved millions of actuations, but found zero difference in image quality compared with a brand new back. It's testing my failing memory, but I think the exercise was to demonstrate the service life advantages of a fanless "heat sink" back design.

I once met a catalogue photographer, in the early P25 days, who had put multiple tens of thousands of actuations onto his back, again he reported zero degradation of image quality.

Personally I'd expect the sensor to be still going strong long after the mounting lugs had worn down to slivers, or the card eject button had broken off, or the back had suffered the actuarially inevitable catastrophic accident.

[Juanito]

What is wrong with your Aptus 22 - are you sure it is a sensor fault (rather than ADC, circuit boards, etc). And have you had a quote for repair?

Yes, I sent it to the MAC Group - they're handling repairs these days. I had long conversation with Pat in the repair department about the problems and whether they could fix it. The sensor is failing and the cost to replace the sensor would be about $10,000. Given that the back is worth about half that, it doesn't make sense to do the replacement. The back is on the way back to me (so I can't check) but I'm guessing it's got somewhere between 30k and 50k captures on it.

John

[John R Smith]

Personally I'd expect the sensor to be still going strong long after the mounting lugs had worn down to slivers, or the card eject button had broken off, or the back had suffered the actuarially inevitable catastrophic accident.

But not in this case. And $10,000 to replace the sensor? How in heaven can anyone justify that?

John

[TH_Alpa]

I second and can confirm this: there are backs out, even still some earlier 12 PMx DBs with 100s of thousands exposures and still working as from day 1.

Best regards
Thierry

I seem to recall Phase One running a test rig that automatically fired exposure after exposure, after running night and day for months they'd achieved millions of actuations, but found zero difference in image quality compared with a brand new back. It's testing my failing memory, but I think the exercise was to demonstrate the service life advantages of a fanless "heat sink" back design.

I once met a catalogue photographer, in the early P25 days, who had put multiple tens of thousands of actuations onto his back, again he reported zero degradation of image quality.

Personally I'd expect the sensor to be still going strong long after the mounting lugs had worn down to slivers, or the card eject button had broken off, or the back had suffered the actuarially inevitable catastrophic accident.

[amsp]

How does a sensor fail? I've never even heard of such a thing. There are plenty of backs, not to mention Canon/Nikons out there with hundreds of thousands of captures on them no problem. If sensors were "failing" even before the camera needed a new shutter I'm pretty sure people would be going back to film en masse. I would talk directly with Leaf/Phase One if I were you, see what they say.

[Juanito]

Here's the problem I'm having:



It's not a card issue or other problem. It's definitely the sensor.

John

[John R Smith]

Sensors do fail, alright. I had a Leica Digilux 2 / Panasonic LC-1 some years back, and sensors were failing on those after only 2-3 years service.

John

[Gary Ferguson]

I was chatting to a Phase One dealer recently and mentioned this point.

He's proven himself rigorously forthright (he advised me against the Phase One/Hartblei T&S lens, saying every one he'd sold had subsequently been returned, and he'll cheerfully tell you why you should get a second hand Mamiya 120mm macro rather than the more expensive Phase One version), but his view was that having been involved in MF digital since the start he couldn't remember ever having a customer who's MF sensor had failed through use.

That's not to say backs didn't fail or need repairing, almost always because of accidents or mishandling, but his view was that the market doesn't realise just how long MF back life expectancy could be. For him the bigger issue was the advance of companion technology (ie connection cables or memory cards or RAW developer updates) rendering a back unsupported and redundant.

It's a question that's particularly interesting given Canon's recent announcement regarding the 1Ds MkIII replacement. Everyone was expecting yet more pixels, but it seems the 35mm sensor battle is capping at. No one knows what the future holds, but if that trends persists then second hand MF backs, in particular the 39 mega pixel or larger backs, could be in strong demand for many many years to come, and questions about their long term reliability will become even more frequently asked.

[ced]

Juanito the image you posted doesn't look like sensor failure the problem looks more like electronic issues.
I am no expert on this but I have never seen a sensor give up the ghost it is more likely to be a peripheral contributor.

[TH_Alpa]

I second that, to me it is not a sensor problem, rather the electronics, circuitry, etc ...

Thierry

Juanito the image you posted doesn't look like sensor failure the problem looks more like electronic issues.
I am no expert on this but I have never seen a sensor give up the ghost it is more likely to be a peripheral contributor.

[marcman]

The studio where I work has been using the same Phase One H20 since they purchased it when it came out circa 2001. No idea how many actuations, and they used to have a second kit as well which was sold off, but I'd say its at least 500k, probably more. In the last 3 years the back has gone in once to replace the flash sync post which crapped out. Even then the back was still usable with a Y connector on the lens...

[Juanito]

Juanito the image you posted doesn't look like sensor failure the problem looks more like electronic issues.
I am no expert on this but I have never seen a sensor give up the ghost it is more likely to be a peripheral contributor.

I was told quite conclusively by Pat at MAC Group repair that this was a sensor issue. Yair has reached out to me on his own to follow up and see what exactly the situation is. I wasn't expecting that but am nonetheless thankful.

Thanks for all the responses. They've helped me to make a decision on how to proceed.

John

[ced]

Juanito please keep us posted on the outcome as it can be interesting.

[Graham Welland]

When it comes to electronics I'd agree with the feedback of others here in that the interface boards and componentry are most likely to fail as they eventually age. In this case it does look like an interface problem due to the regular nature of the error although I suspect it's totally moot as to whether that's on the sensor itself or the board that it is mounted to since you aren't likely to replace one or the other independently anyway.

With respect to image count, I think they are perhaps a better indicator of how many times the back has been handled, mounted & uncounted and generally exposed to the real world. The image quality may well be identical after 100k's of shots but it's just common sense that it'll get physically worn in the real world.

I had a Kodak DCS645M that failed electrically a while ago and that was also a case at the time where it was more cost effective to buy a used replacement for less than the repair/recalibration costs. In my case I found a replacement for $5k vs $7k for a fix back in 2002.

[sbernthal]

50k/yr is not unusual or stressful for a digital back.

The reasons for failure are not continuous shooting, but rather inserting and removing cable, battery and card, mounting and dismounting from camera, and lugging it around. If a back was used for 200K actuation but disconnected from a studio setup only once a month, then it will probably be in fine condition. However, a large number of exposures does statistically indicate other trauma that the back may have incurred.