This is what the problem looks like, is totally unacceptable and one way or another, I had to make it go away, somehow.
Do not be mistaken that this problem is isolated to only Canon imagePROGRAF iPF8400 printers or due to the fact that they were no longer made in Japan. Apparently, there were quality issues when Canon shifted manufacturing to China, but those are unrelated. I now know the problem had already existed on older, made-in-Japan printers, and also on other printers from all of the Big Three (Canon, Epson & HP).
Canon Japan eventually made an official statement via the Southeast Asia regional headquarters to me that any printer using rollers to feed paper will definitely leave marks from said rollers, which will inevitably be more obvious for softer papers, and they do not consider it a machine defect. Read: they cannot do anything at all to help you. Don’t expect any different from the other Big Threes. There have been tens of thousands of online exchanges for well over a decade that perfectly demonstrate this point. Open a case with them at the risk of your sanity.
The iPF8400 shares the same pinch roller mechanism (identical replacement part number specification; it is identical) as all iPF 8xx0 and iPF9xx0 printers, dating back over a decade and half of this platform. The new Canon imagePROGRAF PRO-2000/2100 and 4000/4100 printers share a similar though not identical pinch roller design and are potentially vulnerable to the same flaw. I’ve not heard of any complaints, but then I didn’t either at the time of purchase for my iPF8100 and iPF8400 which I both owned and operated for several years. Watch out.Continue Reading…
Choosing lenses for astrophotography
Establishing some standards
Your camera’s sensor is crooked
Adjusting the camera
Adjusting the lenses
Yet more alignment pitfalls
Possibly another method
In December 2017, it was first suggested to me by my friend and esteemed colleague, Joseph Holmes, that my Sony α7R II’s (or more commonly written as a7R II) sensor might be crooked relative to its bayonet mount. Don’t laugh yet, it’s not a problem exclusive to Sony. I had previously known about the same problem with digital medium format backs from precisely the same person, who put out two extensive articles on the topic over a decade ago, here and here. Neither of us wanted to believe this initially. One would certainly like to assume that 35mm format camera manufacturers, making single-unit camera bodies rather than modular system digital backs, could hold the sensors to tight enough tolerances with today’s technology. Alas, we discovered that it was not quite good enough for what we wanted from our cameras.
A diffuse and complex story unfurls, necessary for the explanation of small details in great detail. For anyone wanting the very best out of their powerful, modern, wide-aperture, breathtakingly-sharp lenses, on equally modern, high-resolution (read: highly revealing of alignment errors) digital cameras, photographing the most optically demanding subject matter in the known universe – the starry night sky – you will want to sit up and pay attention. It’s entirely fine if one does not care about subtle differences between what’s in-focus and out-of-focus. I would not soon be forgetting how many failed to appreciate the camera-shake induced blurring from the original Sony a7R violent shutter mechanism. If one only wants photos displayed no larger than Instagram thumbnails, none of this is pertinent and you should stop reading now. Alright then, some good news! We have fortunately found reasonable solutions to the worst problems. I share them below freely.