Three identical cameras, but different exposure metering!

Beef · 2008-12-29T10:45:50+00:00

Hi Ich habe hier drei gleiche Revue-Spiegelreflexkameras: AC3s, AC3s und die normale AC3 (eigentlich gibt es keine Unterschiede) [ATTACHMENT NOT FOUND] Wi...

Beef

Hi I have three identical Revue SLR cameras here: AC3s, AC3s and the standard AC3 (there aren’t really any differences) [ATTACHMENT NOT FOUND] As I’ve since read, these cameras are identical in construction to the Chinon CP-5. When I meter a particular subject, I get different shutter speeds on all three cameras (with the same lens and aperture). The two AC3s give ‘APPROXIMATELY’ the same reading... with a few slight variations. The standard AC3, however, measures a full stop (and even tends to be a bit higher) differently to the other two (overexposure, compared to the other two). The AC3 has always been in the family, rarely used and very well looked after... and I remember that it always produced excellent pictures. With one of the AC3s (the one I’ve always used so far), I’ve noticed that I always have to perform some degree of overexposure. For example, I expose Fomapan 100 at 64 ASA. I therefore think that the result from the standard AC3 will be closest... though that’s uncertain again, as Fomapan 100 is known to require overexposure anyway (I use Rodinal) :lol: Yes, I know that light meter calibrations have tolerances and that you have to test films. But how can I find out which camera most closely matches ‘reality’? If, for example, I load a C41 colour film, perform the exposure and have it developed at a professional lab, the ‘correct’ image will come out with some camera... how can I easily determine which one without blowing loads of euros on film and development again? ;) I thought I’d compare the reading with a modern digital SLR, a Nikon D80... maybe the settings on today’s light meters are “more accurate” :lol: Or am I wrong about that? Regards Andi

HenningH

Hi Andi, I’m not familiar with these cameras, so just a few thoughts... - Do you have the ‘right’ batteries in all the cameras (mercury, silver oxide, alkaline, etc.)? - Do all the cameras have the same metering system (integral, centre-weighted, spot)? - Transparencies are the most sensitive to correct exposure. - A comparison with another light meter might be helpful. This could be an external one or the one on another camera. - It’s important that you measure relatively uniform objects. This could be a grey card or a similar single-colour surface. It’s also worth noting that different colours can yield different measurement results. - There is, of course, that old principle of using, if possible, just one camera, one film, one developer, ... - Some photographers who use multiple cameras carry an (external) light meter. Swinging regards Henning

Beef

Hi Henning - Yes, the batteries are the right ones and are all the same... they’re new too. - Yes, they all have the same metering system (integral AND centre-weighted) - Another camera? You’ve already got THREE :lol: Would a state-of-the-art DSLR be best, for example? - I’ve tried everything, always the same subject, sometimes consistent, sometimes not. Different apertures and lenses too... but ALWAYS the same focusing distance. - Yes, I actually wanted to stick to just one camera, but I thought that since I already have three of them and over ten lenses to go with them, I could use one or the other depending on the film... for example, one with colour, one without. - Hmm, with an external light meter, you just don’t have the ‘automatic luxury’ of the camera :lol: If I load an Agfa APX 100, take a test shot at 100 ASA with each camera and then develop it with Agfa Rodinal at exactly the specified temperature and time, I should achieve exactly the film’s 100 ASA, shouldn’t I? That way I can surely determine which camera has the most accurate exposure, can’t I? Regards Andi

rmrts

Hello, Have you ever tried taking a reading using a ‘grey card’ (a large piece of grey cardboard will do)? This helps to rule out any peculiarities of the subject. Best regards, Reinhold

HenningH

- Another camera? You’ve already got THREE ;) Would a state-of-the-art DSLR be best, for example?

You’re not supposed to buy another one, just to compare :lol:

- I’ve tried everything, always the same subject, sometimes with a uniform background, sometimes not. I’ve also tried different apertures and lenses... but ALWAYS the same focusing distance.

Try again with a truly uniform surface (grey card)!

- Yes, I actually wanted to stick to just one camera, but I thought that since I already have three of them and over ten lenses to go with them, I could use one or the other depending on the film... for example, one with colour, one without.

I see, but surely two would be enough, wouldn’t they? ;)

- Hmm, with an external light meter, you just don’t have the ‘luxury of auto’ that the camera offers :lol:

Automatic settings are for XP2 or CN400 users, after all. ;)

If I load an Agfa APX 100, take a test shot at 100 ASA with each camera and then develop it with Agfa Rodinal at exactly the specified temperature and time, I should achieve exactly the film’s 100 ASA, shouldn’t I? That way I can surely determine which camera has the most accurate exposure, can’t I?

Negative films are really very forgiving compared to transparencies when it comes to exposure. On top of that, your thermometer, your measuring scales, your agitation rhythm and your clock don’t necessarily give the same readings as those in the Agfa test lab... You’re better off using a cheap slide film! If the two AC3s are comparable, then why not stick to one of them... Regards Henning

Beef

Hi I don’t have a grey card. I always seem to be unlucky in that they’re suddenly out of stock whenever I try to order one :lol: I’ll just use a plain, uniform surface instead...

You’re not supposed to buy another one, just to compare rolleyes.gif

Yeah, I know... I meant that there are already THREE cameras to compare :) I’ll have a go at comparing it with a friend’s Nikon D80.

Sure, but surely two are enough, aren’t they?

Well, maybe one more with a different ISO value ;) ;) ;) And after all, even with TWO, I still need to figure out in which circumstances the measurement is incorrect :)

Automatic settings are for XP2 or CN400 users, aren’t they? biggrin.gif

I don’t get that :) Well, and with transparency film I’d have all that hassle again... I’d have to order it again and that’d take another MONTH ;) And I reckon you’d need a different developer (€)... I’ve heard something about REVERSAL developer. I’d have to spend days testing the new developer and new film again :lol: Cheers, Andi

HenningH

Well, and with transparency film I’m back to all that hassle again… I’d have to order it again and that takes another MONTH :lol: And I reckon you need a different developer for that (??)… I’ve heard something about a REVERSE developer. I’d have to spend days testing the new developer and the new film again :rolleyes:

Nah... Go to dm, Schlecker or somewhere like that, and get yourself a simple Sensia or Elitechrom (or something similar from AS, Paradies, ...) and have that developed at a large-scale lab; then you can more or less assume standardised conditions. You’d be better off saving the self-development of transparency film for later... H.

fotomaik

@Beef You’ve got no choice – go and buy some transparency from Schlecker, find a subject with even lighting, use the SAME lens, and take 10 shots with each camera, one series of exposure times for each. I reckon you’ll spot the differences; after all, the cameras aren’t exactly spring chickens anymore...(25 years old...) and then decide which camera ‘suits you’ I used those cameras myself back in the day; they’re fine, no question, but I reckon the Chinons can’t keep up with the exposure control on today’s SLRs... Regards Maik

TR

I don’t know your style, but I’m going to go out on a limb and say you’re not one of those few perfectionists for whom every detail matters. Your ‘test’ gave a 2:1 result, so I’d go for one of the two cameras that produced the same readings. If you want to “perfect” your work, you’ll need an external light meter anyway. I wouldn’t worry about such things, but would use it all the more in the darkroom later on? :rolleyes: Regards Thomas PS: I once worked with this camera too, and what I really liked about it (since we’re talking about exposure metering here) was the large exposure lock button, which was very easy to reach and hold down. My later Canon A1 had a mere shadow of that. Just as an aside...