H0w to examine the digiback when purchasing a second hand product?

[parkn123]

Dear experience digiback users,
  Since I am new to digiback, would you like to give some advices any checkings when purchasing a second hand digiback ?
  Many many thanks.

Wilbur

[Gel]

Check the focus is accurate on your back.

Check the IR filter is scratch free from idiotic cleaning techniques (more tricky)

Shot 50 frames in fast succession (preferably with studio light)

There's other things I'm sure but look at the back in general. Knocks, dings, signs of impact may not effect the back now but could well do over time.

[parkn123]

Check the focus is accurate on your back.

Check the IR filter is scratch free from idiotic cleaning techniques (more tricky)

How ??

Shot 50 frames in fast succession (preferably with studio light)

WHat is the purpose of doing this??

There's other things I'm sure but look at the back in general. Knocks, dings, signs of impact may not effect the back now but could well do over time.

[Gel]

Magnifying glass and holding the back at an an angle in daylight

50 shots in quick succession will test the back for lockups and consistency in the image I had an 80mm lens that locked up every 6,7 or 8th shot.
I also had a back that randomly had image corruption, always with flash though.

Big expensive items require more diligent testing.

I had a 100mm HC lens I bought secondhand, after only shooting 170+ frames did it need £1200 worth of repairs. I could replace the whole lens for that.

I am speaking from experience, I had a leaf back that needed sending to Israel for a £700 calibrate because it was out enough to cause severe front focusing.

[Ken Doo]

There really is only so much you can do here----and that's assuming you're already familiar with the MFDB and it's workflow.  If you aren't, how would you know if something is amiss?  There aren't many moving parts on a MFDB, and outside of examining the sensor, you really can't be sure of a MFDBs condition absent knowing personally who the seller is or some in depth knowledge of the MFDB you're interested in purchasing. 

This is exactly why a authorized dealer can be so valuable---as they can offer "certified" used MFDBs as well as warranties.  Not to mention answering questions about using the MFDB and workflow.  Even a used MFDB can command a good chunk of change.  A good dealer can help insure that your money spent is a good investment in a suitable MFDB and camera platform that is right for you, and not a really really expensive doorstop.

And no, Ebay is not an authorized dealer.   

ken

[parkn123]

You are correct ; But MFDB is not properly product & as a new comer also want some advices , better than nothing .
Would you like to give constructive advice?

Regards.

[FredBGG]

I am speaking from experience, I had a leaf back that needed sending to Israel for a £700 calibrate because it was out enough to cause severe front focusing.

$ 1,100 for a focus adjustment on a back. That's steep.

[ErikKaffehr]

Hi,

I would not comment on the cost. Also I have no experience with digital backs. Just doing some reading.

Some equipment can be user shimmed, that may be worth some consideration.

This article is worth reading: http://www.josephholmes.com/news-medformatprecision.html

This article is much about focusing: http://www.josephholmes.com/news-sharpmediumformat.html

I'd suggest DSLRs have similar issues, but they need to work with f/1.4 lenses so tolerances may be tighter. All modern DSLRs have live view which essentially warranties correct focus if properly used. Even live view doesn't help if lens axis is not perpendicular to sensor plane.

Whatever you buy, TEST. It is much easier to have things returned/replaced in a reasonable time frame after purchase than after some time and after wear has occurred.

Best regards
Erik

$ 1,100 for a focus adjustment on a back. That's steep.

[Gel]

$ 1,100 for a focus adjustment on a back. That's steep.

That includes all the shipping with a cut for the third party I used in the UK.

Admittedly, it came back fully serviced, they replaced a couple of missing covers and accidentally replaced the IR filter when we said not to, so there was a £700 freebie right there. It was perfect when it came back.

But you know I quickly came to realize MF servicing isn't anything like Canon Platinum CPS, no 2-3 day turnaround. Most annoying when stuff needs to go to Sweden, Israel etc. I guess that's why I'm with Hasselblad, I can drive to the HQ in under two hours.

I'd like to get an extended warranty on my H4D50 but Hasselblad don't do those, which is a shame.

[Dustbak]

I'd like to get an extended warranty on my H4D50 but Hasselblad don't do those, which is a shame.

Yes, they do. It is called Care Plan Coverage. You can apply for it via the login section on their website if you have registered your equipment.

[Gel]

Thanks, I found it.

£2100 GBP per year though. Not worth it tbh, the most any body repair has cost so far is £330

In fact, it's downright cheeky at that price.

[studio347]

After examine the censor surface using loupe(holding backward), try to shoot a LCC shot and examine the LCC file using 100% or more and level tool(in the capture software, and to exaggerate any possible problems) to see any issues such as dead pixels or scratches.
And something to keep in mind...digital backs can be dropped on floor. I saw it for myself when a sleepy digital tech did it, and I heard at least 2 other cases from close friends. The effect of dropping is not clear. But I'd avoid the dropped backs. I heard that the typical sign is the corner metal part would be damaged when dropped even if slightly. I can guess that a rental house digital back might have more chance for this accident. And the rental house digital backs might have a lot of shot count. scratches, dead pixels, any dust or cleaning tissue paper fiber under the glass.

[esox]

The answer is simple : take one with a 6 month warranty.

[parkn123]

The answer is simple : take one with a 6 month warranty.

Yes, I am.

[lance_schad]

After examine the censor surface using loupe(holding backward), try to shoot a LCC shot and examine the LCC file using 100% or more and level tool(in the capture software, and to exaggerate any possible problems) to see any issues such as dead pixels or scratches.
And something to keep in mind...digital backs can be dropped on floor. I saw it for myself when a sleepy digital tech did it, and I heard at least 2 other cases from close friends. The effect of dropping is not clear. But I'd avoid the dropped backs. I heard that the typical sign is the corner metal part would be damaged when dropped even if slightly. I can guess that a rental house digital back might have more chance for this accident. And the rental house digital backs might have a lot of shot count. scratches, dead pixels, any dust or cleaning tissue paper fiber under the glass.

As mentioned above one of the things that often gets overlooked during a purchase of a used back via a private sale is looking for dead pixels/faulty columns and also scratches on the filter. Both repairs can be costly in some instances. A replacement filter on a Phase One runs about $1250 and the unit has to go back to Denmark. For a recalibration (on a Phase One) sometimes a the authorized dealer can accommodate this via getting a RAW file from the back and having it analyzed where a new calibration can be made then uploaded to the back for a couple of hundred dollars, but in some cases it has to be sent back to Denmark.

When we sell refurbished/pre-owned systems we not only do a Physical Inspection , but also the above diagnostics as well as include all new cables & accessories and provide some sort of warranty whether it is the manufacturers or our own.

Lance

[esox]

I did also and that was a real great idea : I bought a package P65+/645DF/80mm used, the body was out of order in fact and the dealer simply changed it for a brand new 645DF... Very happy about warranty.

[Doug Peterson]

I did also and that was a real great idea : I bought a package P65+/645DF/80mm used, the body was out of order in fact and the dealer simply changed it for a brand new 645DF... Very happy about warranty.

Dealers, even good ones, and warranties cannot guarantee you have no problem. They can only guarantee that if and when you have a problem it is addressed immediately, completely, and with as little hassle as possible.

[jerome_m]

As mentioned above one of the things that often gets overlooked during a purchase of a used back via a private sale is looking for dead pixels/faulty columns and also scratches on the filter. Both repairs can be costly in some instances. A replacement filter on a Phase One runs about $1250 and the unit has to go back to Denmark.

According to the Hasselblad web site, CCD cleaning and calibration, which involves removing the IR filter costs 326€ (431€ for the 60 MP back). The unit has to go back to Sweden.