Stephen Gordon

You know what Mark? I didn't know that. And the manual I found online for my L-308 didn't explain that properly, if at all. I clearly have a lot to learn about reflected readings, but your starters-for-ten are super-useful - thanks so much! As for the venerable Mr Mullen, I spent a good part of lockdown working my way through every page of 'Ask David Mullen anything' on REDUSER.net (I feel sure you will know it well yourself). An astonishing resource. Doesn't hurt that I've loved every piece of work of his that I've been able to acquire...

Thanks Mark - I've sent myself to the foot of our stairs. I didn't know, though, that that this was the exact difference to expect, so thanks for making that point clear and continuing my education! I've always found your posts among the most enlightening on this forum - your replies here have been no exception to that rule.

I woke up last night realising I may have made a rookie error: my Canon 518AZ is taking a reflected reading, but I was taking incident readings with my external meter! Oops. Will do some more tests this weekend to establish whether or not this accounts for the large discrepancies, which in that case will not actually be discrepancies at all.

Thanks Mark - I will follow your advice. Shane - your reply is appreciated, and I am reassured by your experience with the stock! Dom - thanks very much: the Sekonic L-308B meter provides readings which exactly match my recently-serviced Sekonic L-398, so I'm happy to rule that line of enquiry out. The camera meter batteries are new, and the correct voltage (2 x 1.35v) but I'm interested in your theory that the calibration has simply drifted after so many years, and your other point about the optics is also good. You also seem to agree with Mark's original idea. I'm very grateful to you all for your time. I've just retrieved another 518 AZ I own which was at work - I will try comparing readings from the two cameras and see if I can garner any useful additional data!

Thanks Mark - I will follow your advice. Shane - your reply is appreciated, and I am reassured by your experience with the stock! Dom - thanks very much: the Sekonic L-308B meter provides readings which exactly match my recently-serviced Sekonic L-398, so I'm happy to rule that line of enquiry out. The camera meter batteries are new, and the correct voltage (2 x 1.35v) but I'm interested in your theory that the calibration has simply drifted after so many years, and your other point about the optics is also good. You also seem to agree with Mark's original idea. I'm very grateful to you all for your time. I've just retrieved another 518 AZ I own which was at work - I will try comparing readings from the two cameras and see if I can garner any useful additional data!

Thanks Mark - Yes, I've read about the light loss from the beam-splitter but was puzzled that the reading was smaller. You seem to be suggesting that the camera's meter may be showing a misleading f-stop while nevertheless providing the correct exposure? I never thought of that - thanks. Anyone else have any other ideas..?

I've just been comparing the auto-exposure readings from my Canon 518 Auto Zoom to those taken with a Sekonic L-308B light meter set to 100 ASA and 18fps. Camera was loaded with Ektachrome 100D, so no filter engaged, and set to 18fps. In all the lighting conditions in which I tested and compared results, the camera's internal meter (set to auto) showed an aperture two full stops less than the external meter. So: if external meter read f/2, camera would say f/4. I understand that reversal stock has very little latitude for over/under exposure, so these results seem to suggest that using an external meter with this camera is not a good idea, as the film will be highly over-exposed. I wondered if anyone more technically savvy than me might be able to suggest a reason for this huge difference? I have to say that when I have exposed reversal stock in this camera on auto-exposure the results have been pretty spot on, but the difference between the two readings is very puzzling indeed! I wonder what Martin Baumgarten might have to say..? All replies welcome - thanks for reading.

Thanks Mark - sound advice for sure, but unfortunately the charges are already paid. Half the roll was used to test another camera, however, so 50% chance of getting something usable back! Looking again on ebay, it seems the Canon 518 Auto Zooms are going for more than I paid for mine even when they are sold 'spares or repair'! The one I had previously worked fine except the auto zoom buttons died, as did the 36fps. Hence my selling it in order to replace with one sold as supposedly fully functioning. To be fair to the seller, I asked every question except whether if it had been tested with film - caveat emptor indeed! Still, I'm hopeful of selling mine as spares or repairs in order to partially cover the cost of an 814 Auto Zoom - which seem pretty sturdy according to folks on this forum...

Great to hear about your positive results, Shane! I have a cartridge of 100D waiting to be exposed as soon as we have some consistently sunny weather here in the UK, so your advice about optimum conditions under which to shoot is very welcome indeed. I will also be projecting, on my recently-acquired Eumig projector, which also has a 150W bulb. I hope it will work out as well for me! Did you also get a scan, and if so, would you care to upload to youtube or vimeo so we can see what you mean..?

Thanks very much Dom - It's clear you are in broad agreement with Mark, and your comments are equally helpful in my understanding of what is causing the intermittent overexposure - the possibility that the film was intermittently jamming and so double or triple exposing occasional frames had not occurred to me. I had already shot another cartridge before I got this one back and saw the problem, so if I get the same result I think I can be pretty sure you are both right and it is the camera. If all is well, I would have to suspect an occasionally jamming cartridge (although, as I've said, I don't remember reading here about anyone having had that problem before). I'm very grateful for the huge experience and highly analytical minds of the members of this forum!

Your analysis of the potential problem is much appreciated. I was puzzled because I hadn't come across this problem before, or read about anyone else having it during the seven years I've been following this forum. Your theory would certainly account for the occasional double image, and the shutter staying open too long would certainly account for the overexposure. I think it is the intermittent and random nature of the problem which most perplexed me in identifying a cause. Thanks again for taking time to look and respond! Would any other members care to chip in, as Mark suggests? (I'm not sure I can really go back to the seller given the several months which have now elapsed since the sale)

Thanks again Mark - I just uploaded the screen grabs to Imgur.com - site says they should be available to view shortly. Link here: https://imgur.com/gallery/6KY2gFo

By the way: I checked the sections shot at 36fps frame-by-frame in VLC and there are no visible flashes that I can see...

Thanks very much for taking a look Mark! You are right about the footage being scanned at 25 fps. I have taken some snapshots in VLC before, after and during the flash as you suggested, but it seems I can only upload 0.29Mb of files and each screen grab is 4.5Mb! Or am I missing something..?

I bought a Canon 814 Auto Zoom in excellent condition, with all functions apparently working, on ebay in April 2019. In May I shot a test cartridge of Kodak Vision 3 200T at the Lickey Hills near Birmingham. The results were very disappointing, with what seems like random, frequent flashes of extreme overexposure throughout, except for a couple of short sequences shot at 36fps which have consistent exposure. The film was processed by Andec and scanned by Gauge Film. I've had no previous problems with any work done by either company, so I think the problem must be with the camera. I am hoping that those with much greater experience of this system and these cameras might be able to take a moment to look at the uploaded footage and offer me any suggestions they may have as to the likely cause of the problem. You can find the footage here: https://www.youtube.com/watch?v=M0xmeKgPj9Y&feature=youtu.be Thanks in advance to the incredibly knowledgeable contributors here! Stephen