Semicircles in the image (Canon T70)

Photux · 2021-01-02T00:44:18+00:00

Hallo zusammen, ich habe mit der T70 das Problem, dass bei manchen Bildern (meist Motiven mit reichlich Licht, aber auch da nicht immer) an einer oder beide...

Photux

Hello everyone, I’m having a problem with the T70 where, in some photos (mostly those taken in bright light, though not always), light or dark semi-circles appear on one or both of the short sides. I’m quite at a loss as to where these might be coming from. In some photos where the problem occurs, it’s fairly easy to ignore, but others are practically ruined by it. I’ll attach a few recent sample images; that will probably say it all. What I can already rule out: - the type of film (occurs with different ones) - the prints (I scan the negatives directly) - the process (it occurs with both self-developed b/w and lab-developed C41 films) - the scanning (the problem does not occur with negatives exposed during exposure in other cameras) - the lenses (it occurs with different lenses) - a manufacturing defect (I can’t find anything comparable to this camera model online) So effectively, the only possible cause left is the camera itself. My guess would be some sort of reflection, but I can’t find anything clearly ‘suspicious’ when examining the light path. The contact plate also looks unremarkable. Logically, light leaks can’t be the cause either, given the dark semicircles. Perhaps one of you has an idea – I’d be very grateful for any tips, as the T70 is currently my most ‘usable’ and reliable camera – and, in my opinion, also underrated once you’ve got used to its ugly exterior. Best regards Daria

KlausWehner

Hello Daria, The "semicircle" is always in the same place on the negative. That’s why I suspect there’s something in the mirror box near the shutter that’s casting a shadow onto the negative (perhaps a hair). Here’s how you can check: Remove the lens, open the back cover, set the shutter to "B", and press the shutter release. With the shutter open, you can now look through the camera and may spot a hair, which should be somewhere near the shutter plane. You’ll need to remove this carefully. Good luck! Best regards, Klaus

Photux

Hi Klaus, The idea is actually so simple that I hadn’t thought of it myself. I did lift the mirror up carefully once, but with the shutter closed. I’ll have a look at that – thanks for the tip! Best wishes, Daria

Photux

I’ve finally taken the time to have a proper look at it. And I found… nothing. Not a hair or anything like that, nor anything else. So it remains a mystery for now. At the same time, I’m toying with the idea of getting a T60 as the ‘last of the line’. Unfortunately, because of the collection of lenses I’ve accumulated over the years, I’m relatively tied to the Canon FD system.

gertfritsche

Hi photux, If you're after a T70: I think I've got two left here, one of which should still be working. As I'm trying to sort through my stuff and streamline my collection of gadgets: I'll have a look if you're interested. Reimbursement of postage would be enough for me. Cheers Gert PS: Of course, no guarantees...

KlausWehner

Hi Daria, If the view through the mirror box of your T 70 is clear again, the problem should certainly be sorted. Perhaps you could check this out with a test roll of film when you get the chance. Just as quickly as a hair can get into the mirror box, it can fall out again. Best regards, Klaus [hr] Hi Gert, A Canon T 70 is my ‘lab camera’ for test shots. However, it has recently had a few technical issues, so I’m looking for a replacement. If your camera is still available, I’d be interested. Thanks and best regards Klaus

Photux

Gert Fritsche wrote : Hi Photux, If you’re after a T70: I think I’ve still got two of them here, one of which should still be working. As I’m trying to sort through my stuff and streamline my collection of gadgets: I’ll have a look if you’re interested. I’d be happy with a refund of the postage costs.

Hi Gert, I certainly wouldn’t say no to that! But as Klaus asked first, I’d be happy to let him have first refusal if necessary. The look of the whole T-series is... well, it takes some getting used to, but in itself the T70 is – for my purposes – a good ‘workhorse’ for everyday use. I don’t need autofocus or any fancy automatic exposure systems; I prefer to set everything manually anyway. :)

Klaus Wehner wrote Hi Daria, if the view through the mirror housing of your T 70 is clear again now, the problem should certainly be sorted. Perhaps you could check it out with a test roll of film when you get the chance. Just as quickly as a hair can get into the mirror housing, it can fall out again.

Hi Klaus, the problem had been recurring for quite a while now, so that would be a strange coincidence... but who knows, I really have no choice but to give it a go! Best regards, Daria

gertfritsche

Hi everyone, I’ve had a bit of a rummage: one T70 is dead! The second one works. It does have a sort of Newtonian pattern on the display, but that doesn’t really bother me. I think. I’d say: please agree amongst yourselves who needs it most. I don’t really mind either way. I could send the loser a Speedlite as a consolation prize – without a warranty, of course – but it worked right up until the end. One thing struck me: is it normal in TV mode for the camera to automatically correct the exposure time with frantic flashing when the exposure is running low? I was a bit surprised by that earlier. Deliberately setting it wrong (or making your own decision) is probably only possible in manual mode. So: get in touch once you’ve reached a decision. Gert