Canon T70 with FL lenses

[Berndt]

Does anybody have experience with operating a Canon T70 with old Canon FL lenses ?

I got one yesterday, but the manual is confusing to me
www.cameramanuals.org/canon_pdf/canon_t70-2.pdf

It only mentions the "stopped down AE-mode". I know, what "stopped down metering" is, but this mode is basically just an "aperture priority mode". It should be possible, to use old FL lenses in "shutter speed priority mode" as well, which basically means "manual mode" on this particular camera.

The important question now is: Does the lens need to be stopped down if measuring the light on this camera or not. I think not, but I am not sure, how this camera works.
Running the T70 in manual mode, you can set the shutter speed and the camera measures the light ( through the lens, I guess ) and suggests an aperture, which is displayed in the viewfinder. So, I actually just need to set the aperture manually on my lens to that f-stop AND ( as I tested ) ALL of my FL lenses are closing the aperture down to the right number WHILE taking the picture.

That would be actually the easiest way to use my old FL lenses on the T70 ... but it is not mentioned in the manual. So, there is something wrong with my way of thinking ?

[Rachel]

berndt,
Yes, you need to select Stopped Down AE mode to use FL lenses on the T70 but you have to set the lens to Manual aperture operation and then the camera will measure the available light at working aperture. You can't do open aperture metering as the FL lenses do not have the aperture follower cam so the camera cannot see what aperture your lens is set to.
I've not used my T70 for years now and had to look up the instructions for using non-coupled accessories on it. The camera will display the measured shutter speed in the top LCD but the display in the viewfinder is a little odd with faster speeds (higher then 1/90th) shown as H.L OR H.H.
BTW I was pleased to find that my T70 is still apparently working OK

[truls]

I guess the T70 works like EOS (film) with m42 lens, stop down metering, the camera choose correct shutter speed. A tip is to try this and compare readings from T70 from another light meter or camera.

[Berndt]

Rachel,

first of all, thanks a lot for your quick reply and digging up your T70 again

It's not, that I want to be right ... I would be just happy if I could understand, why I am wrong, but I still can not fully understand, why the "manual mode" wouldn't work.

In manual mode, you can set the shutter speed, right ? So, what the camera is measuring, must be the aperture, which is required to get a well exposed picture. Stopping the lens down at this point, wouldn't make any sense to me BUT IF the lens is fully open, the camera should be able to do just what it is supposed to do in that mode ... measuring the required aperture. If this will be set manually on the lens, no communication between lens and camera would be needed.

This is basically the procedure, described in the chapter "Manual Mode" on page 48 of the camera manual. "Remove the aperture ring from the "A" setting." is written there, which would actually turn any FD lens into a FL lens, wouldn't it. Ironically into a FL lens in "AUTO" mode though, because in AUTO mode, FL lenses do close the aperture to the set number just in the moment, the picture will be taken.

I still can not see any logical reason, why the manual mode on that camera wouldn't work with FL lenses ( without stop down metering ) too ... and that would be the way, I actually want to use the T70. I have many beautiful Canon FL lenses ( the 19R, the 58 mm, F:1.2, the 85 mm, F:1.8 and the 55-135 mm for example ) and have been searching for the perfect body for them. I tried an AE-1 and FTb, which are not really convenient to handle with FL lenses ... but if the manual mode would work on the T70, this would be the best solution for my "body problem", I think.

So, where is the node in my mind ?

I guess the T70 works like EOS (film) with m42 lens, stop down metering, the camera choose correct shutter speed.

That would be the suggested stop down metering mode, which is actually an "aperture priority mode". There are other techniques on other Canon SLRs, also working with FL lenses, where you can also set the shutter speed, stop the lens down and adjust the aperture in a way, that the needle in the viewfinder has to match a certain point on the scale ... but that doesn't work on the more electronically designed T70.

[hansz]

Berndt,teries...
I still have 2xFT QL bodies for sale... It is the original body meant for FL lenses, even the lightmeters work...
(that is, if you have the right voltage, which I still have, buying some of the last Varta Hg-batteries...)
Hans

[Berndt]

I still have 2xFT QL bodies for sale... It is the original body meant for FL lenses, even the lightmeters work...

I would seriously consider buying one from you, if the shipping costs wouldn't be higher then the price of those cameras here. Old Canon SLRs are mostly cheap in Japan, just those Voltage modified batteries are always some pain in the @ss somehow. So I found this Canon T70 in my favorite camera shop this week, which uses "normal" batteries and I thought the light meter might work even better than the one on the SLRs of the 60s. I paid less than 20 Euro for it in mint condition ;D

[John Farrell]

I used to use Zinc-air hearing aid batteries in my FT, but these days I just put an alkaline cell in the thing, and use the film speed setting to adjust the meter.

[Rachel]

Oct 6, 2012 8:15:45 GMT -5 Berndt said:

Rachel,

first of all, thanks a lot for your quick reply and digging up your T70 again

It's not, that I want to be right ... I would be just happy if I could understand, why I am wrong, but I still can not fully understand, why the "manual mode" wouldn't work.

In manual mode, you can set the shutter speed, right ? So, what the camera is measuring, must be the aperture, which is required to get a well exposed picture. Stopping the lens down at this point, wouldn't make any sense to me BUT IF the lens is fully open, the camera should be able to do just what it is supposed to do in that mode ... measuring the required aperture. If this will be set manually on the lens, no communication between lens and camera would be needed.

This is basically the procedure, described in the chapter "Manual Mode" on page 48 of the camera manual. "Remove the aperture ring from the "A" setting." is written there, which would actually turn any FD lens into a FL lens, wouldn't it. Ironically into a FL lens in "AUTO" mode though, because in AUTO mode, FL lenses do close the aperture to the set number just in the moment, the picture will be taken.

I still can not see any logical reason, why the manual mode on that camera wouldn't work with FL lenses ( without stop down metering ) too ... and that would be the way, I actually want to use the T70. I have many beautiful Canon FL lenses ( the 19R, the 58 mm, F:1.2, the 85 mm, F:1.8 and the 55-135 mm for example ) and have been searching for the perfect body for them. I tried an AE-1 and FTb, which are not really convenient to handle with FL lenses ... but if the manual mode would work on the T70, this would be the best solution for my "body problem", I think.

So, where is the node in my mind ?

Hi berndt.

If you set an FD lens to Manual mode it doesn't set the lens to stop down mode. It just tells the camera which aperture you have selected. It adjusts the light measurement from the fully open lens with the aperture information to give a correct exposure.

An FL lens has no way to tell the camera which aperture is selected as it doesn't have the appropriate cam on the back of the lens. You have to set the lens to Manual mode and meter at working aperture. That's why you have to use the Stopped-down AE mode.

EOS cameras are different. If they detect a non-EF lens they just select a shutter speed for whatever light the lens is passing with no adjustment and assume it's at working aperture.

[Berndt]

An FL lens has no way to tell the camera which aperture is selected as it doesn't have the appropriate cam on the back of the lens.

Right, but it doesn't have to. No matter if a FD or FL lens is mounted, the T70 measures the light at an open lens and just suggests the correct aperture ( at a certain chosen shutter speed ), which needs to be selected manually on the lens. The camera does not need any information from the lens in manual mode. It is just important, that the lens is closing down at the selected aperture in the moment, the picture will be taken. So, from what I noticed and tested, FL lenses in AUTO mode ( AUTO on the lens, NOT the camera ) do behave exactly the same as FD lenses in Manual Mode ( here again: on the lens, NOT the camera ). Any AUTO mode on the camera should of course not work with FL lenses, because there is, as you said correctly, no communication possible between camera and FL lens.

However, the stop down metering simulates some kind of auto mode ( an aperture priority mode ), because then, the T70 measures the light at the right ( stopped down ) aperture and choose a shutter time automatically. But for me, this method doesn't make much sense in reality. If it is not all about wanting a certain DOF, we mostly want to know the right aperture at a save shutter speed ( 1/125 sec for example ) PLUS focussing with a stopped down lens is not really easy. Much easier and faster to select a certain shutter speed, focus and read the suggested aperture in the viewfinder at a full open lens, set the aperture on the lens and press the shutter button.

I am actually more and more convinced, that this should work with FL lenses as same as with FD lenses, even the manual tells something different.

[Rachel]

Hi berndt. You are doing my head in over this
Your idea sounds a good one but it doesn't work.

I have tried your idea with two 50mm f1.8 lenses; one FL and one FD. I set the camera to TV mode (shutter priority) ; FL lens to A(uto) mode so that the lens aperture stays fully open; FD lens to f1.8 ... it makes no difference what aperture setting you set the FD lens to (as long as it is not on A) as it always stays fully open and the camera ignores which aperture you have set it to. The aperture suggested by the camera for the two lenses is very different.

There are two extra pins (as the manual calls them) on the back of an FD lens; 1) the aperture follower but we can ignore that for TV mode; 2) a pin which tells the camera exposure system the maximum aperture of the lens .... this is probably what is messing up the exposure readings.

[Berndt]

Hi berndt. You are doing my head in over this

I am not familiar with this English expression. Does it mean something like: "I make you crazy with this" ? If so, I have to apologize

The aperture suggested by the camera for the two lenses is very different.

And that should actually be ... impossible ? I tried a few readings with different FL lenses today. What I did as some kind of hardcore test before waisting a roll of film was, taking pictures with my digital GH1, using the settings ( aperture, shutter speed ), given by the T70. The readings have been quite precise.

2) a pin which tells the camera exposure system the maximum aperture of the lens .... this is probably what is messing up the exposure readings.

But you have been talking about FD lenses, right ? So there shouldn't be anything, messing something up, because the manual mode on the T70 is made for FD lenses, isn't it.

I also couldn't verify your experiences yet. I tried an exposure metering on a FL 58 mm F:1.2 and a FD 35-70 mm lens ... no difference. The readings have been exactly the same, even the lenses are totally different.

Aaaaaaah ... very strange all this

[truls]

I think you have two options. Full manual exposure, you deside shutter speed and aperture. Second I assume you can use aperture priority, you pick an aperture, and the camera choose shutter speed. I remember the T70 displays selected shutter speed in the top display, not in the viewfinder.

[Rachel]

Well ........ I give up on this Just take some photos berndt.

[Berndt]

Full manual exposure, you deside shutter speed and aperture.

That's the mode, I want to use with my FL lenses.

Well ........ I give up on this Just take some photos berndt.

I'll do so but ... thanks anyway. Reflecting thoughts with others always helps !!!

I also might consider to use my FD 35-70 mm with it as well. I think, this "Tele program AE" looks also interesting. In that mode, the T70 claims to choose always the fastest possible shutter speed, which should mean in other words "the shallowest DOF".

The thing is just ... so many cameras are still waiting in line to become tested ... hahaha ... the curse of a camera collector

[Berndt]

The aperture suggested by the camera for the two lenses is very different.

Rachel, it did not let me in peace, why your result has been different from mine. I think, I was just lucky. The Canon FL 58 mm lens shows ( accidentally ? ) the same readings as a FD lens in manual mode ... BUT you are also right. I tried other lenses and made the same experiences as you. However ... technically still hard for me to understand, why all this is so At least my favorite FL 58 mm 1.2 lens seems to work, for others, I might be able to adjust the difference simply by changing the ASA.