What's the expected life (shutter actuation wise) for a Phase One P45+.
Also what is the best way to check shutter actuations?
What's the expected life (shutter actuation wise) for a Phase One P45+.
Also what is the best way to check shutter actuations?
The P45+ as a digital back, like all Phase One backs have very little in the way of mechanical things that could go wrong; there the locking to the body, the card door and release. The rest as far as I know are all electrical. That said, there's little from my understanding to actually wear out. But crap happens.
As far as telling how many image files have been captured you need to turn the back on and go to the menu. Look for the screen that shows the firmware and you'll see how many files have been processed.
Hope that helps.
So I guess my question is when would one start being concerned that the back is wearing out? I know 50k is barely breaking in a DSLR but my understanding is that MF backs aren't made for that kind of use? Or is that incorrect?
I think you've got it backwards. The medium format camera and its lenses are more similar to the DSLR in that they are subject to wear and tear with use. A MFDB has very few moving parts. I recall reading that the Phase One MFDBs or sensors are engineered more towards a million captures. No one will ever know, because here in Dante's Forum it's always customary to trade in our MFDBs and upgrade as soon as our wallets have recovered from the first time round.
Of course those same old MFDBs are still working, and you'd be surprised how many MFDBs are simply moving around back and forth exchanging ownership amongst the GetDPI family.
I'd place my money on a MFDB far outlasting any DSLR in use. Wear and tear on a medium format camera body is a different story.
Two totally separate things, a (any) DSLR vs. a (any) digital back. The camera body's weakest part is the shutter. There's also all types of mechanical things going on every time the shutter button is pressed. No so with a digital back where electrons are working to save the file (very simplistic point of view). Bottom line as far as I know and understand it a camera body will wear out much sooner than a digital back.
That said, if buying a used back it would be best to have it first checked out with a trusted dealer to insure everything is okay.
I'm now on my 4th digital back, and no none of them ever wore out. My first one was a P30+ I bought new then later traded/upgraded to a used P45+ which was later traded/upgraded to a used P65+ which was later traded/upgraded to a used IQ160. My current back will soon be traded/upgraded again to a used IQ180. While things certainly can go wrong the one thing I've never been concerned with is my digital back wearing out.
Ken responded will I was typing. I remember reading the same 1 million figure but didn't want to share it as I thought I had mis-remembered the figure.
You've now heard from 2-photographers. Hopefully Doug or Steve or someone how actually sells and has a company that offers customer service will chime in.
I was once invited to visit Phase One but I didn't go because I was told I'd be escorted the entire time by armed people and that I had to keep my hands in my pockets and a body search was to be made at the end. Took all the fun out of it.
All kidding aside digital backs (at least Phase One from personal experience) are like the engerizer bunny. They just keep going...
I have owned many digital backs (Leaf DDB I then II, Phase One H5, H10, H25, P25, P45+,P40+, P65+, Leaf Aptus 12, Phase One IQ180). I also spent 7 years as a senior manager in an organisation in Australia that owned and operated more than 30 backs in studios across the country that were deployed in shooting most of the retail catalogues for the big retailers in Australia. These backs were shooting hundreds of frames each day, in the case of some clients by multiple shifts working 2 and occasionally 3 eight -hour shifts a day. In the last ten years, my personal backs have been dragged through Arabian deserts in high summer, SE Asian jungles during the monsoon and high in the snow country in the Swiss Alps. What I can say is that I have NEVER seen a back become unreliable due to overuse. Mechanical parts sometimes fail. These include memory card doors, a couple of Leaf cooling fans (a miracle considering summer temps in Oz and the backs almost continual use) and once, a mount lock. All other repairs we had were due to being dropped or carelessness causing scratches to sensor protectors. The electronics/sensors seem to be pretty much bulletproof.
If your question relates to a potential purchase of a used P45+, the the primary concern I would have would be to satisfy myself that the back has not been physically abused. Usually, if a back has been banged and bashed around, the case will tell you pretty clearly. The P series cases are tough as nails (my P25+ was dropped on concrete floors and on rocks more times than I care to admit, though happily, none of my subsequent backs have bounced). The black paint can show some wear on corners and sharp corners but this is not so worrisome. On the other hand if there were any dings in metalwork, or gauges in paintwork that was clearly not ordinary wear on exposed edges, then I'd treat the back as if it had ebola.
Bottom line is, in my view, unless the back has a huge amount of exposures on it (for me, that grey area approaches in the 300-400k exposure zone, but you have to form your own view. My view is based on my own observations), I would consider buying it if it appears in good physical condition. A few test shots in various conditions should reveal any calibration issues, though these should have been mostly identified by first owners and sorted under warranty.
Best of luck.
Thanks for all the great advice!
The next question is how much is a P45+ in V mount worth?
seen from an technical standpoint, way less than any camera with the 36mp sony sensor.
- better dynamic range
- better iso performance
- better, smaller, more universal bodys
- can be lighter and more compact than any MF system
but there are reasons to buy such an digi back of course, for some people.
- updating an existing system
- they believe in the cmos color, or look, what ever that means... voodoo imo
- same as the above, but replace the cmos with lenses... voodoo imo
if you want an nice P45+, be prepared to pay about 4-5 times as much as an A7R goes for.
Last edited by mbn; 31st October 2014 at 08:23.
Shoot the Sony A7r and a MFDB system side by side, especially a nice compact technical camera.
Keep what gives you the most kicks, grins, and giggles.
Better yet, get both. I didn't like the A7r---felt like a fancy P&S. It sings as an IR camera though!
I'm currently using an IQ160 on both a DF and WRS and also have a Sony A7r converted to shoot full spectrum. To me and what I want and am looking for; the IQ beats the image files from the 7r. I have always preferred the files from any medium format back to any 35mm (and I've shot with the Ds, Ds II and Ds III) the nearest I've come was when I also shot with a Leica M9 while still using a P45+. But you use the tool that fits the location and hope for the best.
I'll be going to Moab and the South Rim in December and will in all likelihood take everything with me. If the conditions are perfect I have a hike planned that will require several hours and a lot of elevation change and since I'm getting lazy I plan on taking the 7r. I also have a few spots in mind that require just a little effort and will take the WRS. I also have another location where I'll in all likelihood take the DF. In the end I also have a close to 15 mile hike that I haven't been on before and since I'm uncertain what I'll be running into plan on going light in camera gear so I can take more water and plan to taking the 7r with a new (I should get it by then) 16-35.
In a perfect word where I had someone carrying my gear for me I'd never take anything other than medium format. In other words let the situation detect the equipment; not what other people feel is best.
I'd worry less about actuations and more about flight time in aeroplanes. Cosmic rays and other high energy particles will gradually kill off pixels etc over enough time. Seriously.
If it wasn't for the use of the word seriously I'd have thought you were trolling, but that's not a game I've ever seen you play Graham.
"In the end, it's all about the pictures"
I know it sounds fanciful but air travel and exposure to high energy particles such as gamma rays fries lcd, ccd, and memory chips over time. No, I'm not making this up. It's a cause for dropped pixels and memory bits.
Now should you wrap your camera in lead? No, don't bother.
But perhaps he is overstating its severity - consider that cameras on the Hubble Space Telescope have operated for up to a dozen years each before replacement, and that is in the much harsher radiation environment of space. I've worked with HST exposures that are so peppered with cosmic ray hits that it's hard to distinguish any of the real stars. This is one reason why very long exposures are subdivided into multiple shorter ones, and stacked with aggressive statistical thresholding.
1 Member(s) liked this post
Perhaps I should clarify my original post. I wouldn't be worried about the electrical effects of running a back with lots of actuations. I was actually being somewhat ironic about worrying more about cosmic rays as what I'd care about with a used back.
I do agree however that a high shot count probably is associated with more physical wear and tear such as sensor cleans, mount/unmount on camera bodies, button wear plus any associated wear on the connectors if it's been used for tethered shooting with cables being shoved in & out of the various orifices on the back.
The reality of sensor exposure to high altitude conditions is just that more pixels will end up being mapped out. You might even get dark/stuck pixels on the LCD too over time. Is it a serious reason to panic? Not in the slightest unless you're up in the space station.
I fly 150k+ miles a year and so I'm somewhat conscious of the health impacts of sitting in an aluminum tube at 36,000 ft for hours on end (8hrs today for example). That includes being irradiated, although not as much as being stuck around other people, jet lag, DVT risk, being turned into a raging alcoholic in first class etc.
Last edited by GrahamWelland; 1st November 2014 at 22:48.
My website3 Member(s) liked this post
Yes, it's amazing what you can do with a 57600 mm focal length telephoto!
Here's something I made with it many years ago...supernova remnant CTB80, an RGB tricolour composite with R = ionised Sulphur, G = ionised Hydrogen, and B = Stromgren y continuum band. The white circle marks the location of a radio pulsar that we were trying to locate in visible light.
I get a kick out of the fact that the Hubble has a native focal ratio of f/24, and many of its instrument modes increase that number, to as high as f/288. You can already picture a few photography "gurus" throwing up their hands in horror - "You mustn't shoot at such small f-stops - you'll get terrible diffraction softness!" - or even better - "Of course, the reason they use such slow f-ratios is to increase the depth of field"
I think the diffraction police just died.
My little corner on the internet.2 Member(s) liked this post
My point is that
(1) being diffraction limited is good - it cannot be improved upon; and
(2) what's more important than obsessing about a specific f/stop number is what your sampling of the PSF is. With chunky pixels, it's entirely appropriate to use f/[big number].
You seemed to be inferring earlier with your sarcastic "mustn't shoot at such small f-stops" comment that those who consider such things are somehow missing the bigger picture.
Regardless of "chunky pixels", there is no arguing whatsoever about the simple fact that because that image you are sharing was shot at such a small aperture, you are losing a huge quantity of information because of diffraction problems.
I'm not referring to the cross here - I'm referring to the fact that you have point sources of light that, due to diffraction issues that are exacerbated by the size of the chosen aperture, are masking data in the image.
Look at any of the "bright" stars in that image. Due to diffraction, they are destroying data that would (theoretically) otherwise be available.
Isn't that the reason why photography "gurus" take diffraction into consideration?
The case is that NASA is not stopping down, they use a barlow lens (tele extender) to increase the focal length. So f-stop is going down as it is diameter of the mirror divided the focal length.
To achieve a good spatial resolution on large pixels they need to have a large image. The angular resolution of the telescope is limited by the diameter of the lens (mirror), but an extended focal length is needed to utilise that angular resolution with fat pixel sensors. I guess that those pixels are large (200 microns?)
Now, why do they have that large pixels? Well my guess is that they try to catch photons from far away which are not very abundant. Increasing the area of a pixel increases the probability of detection.
Now let's assume that pixel size is something like 200 micron. That is 29 times the size of a P45+ pixel, but area would be 29x29 = 841 times larger. So if a p45+ pixel would collect 10 photons the 200 micron sensor would yield 8410 counts. Now, the P45+ has a readout noise of about 10 electron charge, so SNR would be 1, that is a barely usable signal. The sensor on Hubble may have much lower readout noise as it is in a very cold environment like 78K.
Last edited by ErikKaffehr; 5th November 2014 at 12:24.
- OP asked about P45+ lifetime
- Graham commented on lifetime effects of sensor and LCD aging by radiation exposure
- I agreed with Graham, but added that HST sensors last well despite intense radiation bombardment
- Erik commented that HST must be a great long telephoto
- I agreed, and showed an example from my own HST work...which reminded me of a time when someone who should have known better criticized NASA for using such large f/numbers, on the basis of the spectre of diffraction.
- and so here we are, talking about space telescope point-spread functions and diffraction, when we should be talking about the lifetime of a particular digital back.
What is the pixel size?
I was also a bit surprised to read that original sensor have been cooled by nitrogen, as it is quite cold out there. But than I realised that with near vacuum conditions there would not be any cooling by convection.
Nice picture, by the way! Surprised to see it in colour, though!
And even if the average sensor temperature was still very, very cold, any uncontrolled rise and fall in temperature, however small, is undesirable from the point of view of maintaining a stable instrument calibration during science programmes. In other words, just cooling isn't enough - it must be regulated cooling to a set point of temperature. So the WFPC2 was maintained at -88 Celcius.
The visible light cameras (like the WFPC2, ACS, and WFC3) actually don't use cryogenic coolants like nitrogen or helium - they use thermoelectric coolers instead. This gives them an essentially unlimited lifetime. OTOH, infrared cameras (like the NICMOS) require deeper cooling - otherwise the camera detects its own thermal infrared signature as an interfering background! - and that means cryogenics. However, the Helium boils off over time, which sets a limit to the useable lifetime of the camera - unless a servicing mission flies in to replace the dewar.
(And BTW, Ctein's rant about this, while interesting, misses the point: tricolour techniques are not at all confined to literally use red, green and blue filtration - any three spectral bandpasses can be used, from gamma rays down to radio waves).
Nice to hear about "unlimited lifetime". I guess that the HST is one of the most valuable resources to astronomers.
Well, my thinking was more like that HST time is pretty scarce, I guess. NASA publishes some images for sheer beauty, but I guess that many observations are monochrome. So I guess that if nice multispectral images needs to be shot, there needs to be a scientific need for that.
Thanks! It's in colour because I made a tricolour composite of grey images through 3 different filters. An old technique that dates back to James Clerk Maxwell in 1861.
BTW, It could be nice if you would elaborate a bit more on the PSF/diffraction and pixel size issue.
Last edited by ErikKaffehr; 6th November 2014 at 09:37.