Mamiya 645 Pro TL + FE401 Prism Finder newbie

dblv

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This is very much a newbie dumb question that I still need to ask anyway. Brand new to medium format coming from 35mm and I just picked up a Mamiya 645 Pro TL with the FE401 Prism Finder. I shot my first roll with it yesterday (yet to be processed). I tend to purposely overexpose things a couple of stops by rating my iso half the box speed and metering from shadows. I know some people don't care for that but that's just the way I like to do it with film. What I ran into with this system is that when I wanted to shoot wider open for more shallow depth of field the Prism Finder would just blink OVER (I'm shooting auto-exposure by the way, since I tend to be shooting on the fly). So of course I'm aware that I'm overexposing, but when I do this with my 35mm camera it will still tell me the shutter speed. How do most people go about purposely overexposing with this system when shooting more wide open?
 

MattKing

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Welcome to APUG.
A flashing "OVER" indicates that the meter thinks that the light levels are so high that the shutter speed cannot be adjusted to a fast enough setting for correct exposure.
Your various choices may result in this, but it is also possible that the meter is not functioning correctly.
Which setting are you using on the meter - Averaging, Spot or Evaluative?
If your preference is to generally over-expose the film by 4 or more stops every time (which your description implies) I would suggest setting the EI to 1/4 the ISO and letting the meter do its work.
But before doing that, I would suggest learning more about the capabilities of this new-to-you medium, by metering and exposing the film "normally" (box speed) and evaluating whether controls available to you when printing will give you results you like.
 
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dblv

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Thank you Matt, I had rated Portra 400 as 200 and was still unable to open up to 2.8 or even 4 quite often without getting the flashing OVER. It was even an overcast day, although quite brightly overcast. Still, doesn't that does seem rather strange? Quite possibly there is something wrong with the meter. Or I can try rating it 100 or 50 to see if it's possible in that scenario.

Meanwhile, for that first roll I did end up using it as a test roll, rating it as box speed and stopping down until I got a proper reading. We'll see how those turn out, but I would like to be able to shoot wide open in bright situations.
 

MattKing

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In Texas, on an overcast day, one would expect something like a meter reading of 1/250 at f/11 for an EI of 200.
Which equates to 1/1000 at f/2.8.
The problem could also be with the film back, as that is where the film speed is set. Or with the connection between the back and the camera.
 
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dblv

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Thanks again, Matt. It could be I was just over that 1/1000 shutter speed limitation. How do folks typically get around that? Say I had rated it at 400 box speed and was wanting to take portraits wide open. I see examples of wide open portraits on sunny days from this camera and lens all over the place so I'm wondering what I'm missing here.

I will definitely have to investigate whether there is an issue with the camera as well. As I just acquired it, I don't doubt the connections between the back, camera and prism finder could all use a good cleaning just to be safe. And if the exposures from that test roll all come out wonky that'll be a good indication that something is wrong. Thanks!
 

MattKing

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dblv said:
Say I had rated it at 400 box speed and was wanting to take portraits wide open. I see examples of wide open portraits on sunny days from this camera and lens all over the place so I'm wondering what I'm missing here.
Click to expand...
You can always intentionally over-expose using manual. Or you could use the exposure compensation control to add over-exposure.
A polarizing filter cuts two stops of light.
Neutral density filters are available.
Portra 160 and Ektar 100 films can be used.
I usually use my 645 Pro and N meter prism either with manual metering or a hand-held meter (frequently in incident mode), but then again I rarely want to shoot wide open - I like a little bit of depth of field.
 
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dblv

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Once again, thanks so much Matt. I have some playing around to do, and probably a pack of Portra 160 to buy. And just to be clear I like a little bit of depth of field as well. It's just nice to have the option of shallowing it out as well!
 

ac12

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Your question indicates to me that you need to learn more about exposure.
And you need to understand equivalent exposure.
  • Shadow exposure:
    Question, is the shadow only ONE stop less light than the lighted subject, or is it more?
    The problem with metering shadow, is there is a wide range of shadows from light to deep.
  • Equivalent exposure:
    Using a base exposure with sunny 16 rule; 1/ISO speed @ f/16.
    Then determine the equivalent exposure settings that will give you the same exposure.
    Example for ISO=200
    • 1/250 @ f/16
    • 1/500 @ f/11
    • 1/1000 @ f/8
    • 1/2000 @ f/5.6
    • 1/4000 @ f/4
    • 1/8000 @ f/2.8
  • Practical equivalent exposure:
    You are limited by the max shutter speed and max and min aperture settings of your camera. You CANNOT just set the aperture or shutter speed at whatever setting you want to shoot at. That setting may be outside the limits of the equivalent exposure for your camera and lens.
    Example: Using the above table at ISO 200. To shoot at f/2.8, you have to set the shutter speed to 1/8000 sec. Can your cameras shutter speed get up that high? Mine cannot. With a max shutter speed of 1/500 sec, I can only open up to f/11.
  • Metering:
    If you are going to have the camera auto adjust the exposure for you, you need to trick the camera by changing the ISO setting to match what you want to expose at. Because auto generally means the CAMERA will set the exposure, not you. So if it says OVER, I expect it to be overexposed by an unknown amount. I do not know how the metering works on the Mamiya 645 so cannot be specific. So here you need to READ the camera manual and understand how the metering works. If you do not have the manual, get it.
  • Film and ISO levels
    You ran head on into the reason that I do not like 400 speed film.
    You cannot get any kind of exposure flexibility when you are or are almost maxed out at 1/500 sec at f/16 during the day (sunny 16 rule).

    Today, I generally use medium speed film about ASA/ISO 100.
    But even at ISO 100, I cannot open the aperture to f2.8. At f2.8, I need a shutter speed of 1/4000 sec. This is way faster than the max shutter speed on my camera.

    There is no ONE film that will let you shoot everything you want at any time of the day in any lighting condition. This is why there are different speed films. It is your duty as the photographer to select the film (speed) to match your shooting conditions.
If you want to shoot at f/2.8 during the day, you need to look at how to make it work.
  • SLOW film, that will give you a usable equivalent exposure at f/2.8
  • Reduce the amount of light hitting the lens (with a ND filter of the proper value) to get the light level down to where it is within the equivalent exposure range settings of your camera. If your max shutter speed is 1/500 sec, then you need at least a 4 stop ND filter.
  • Combination of the above.
BTW, I don't mean to be a smart a$$, but when you go off "auto" mode on the camera, you really need to know about exposure and YOUR camera.

So learn about exposure and read the camera manual.

Gud Luk
 
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Huss

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I use the same camera.
First off, as others have shown, you are outside the operating envelope of the camera if your subject is standing in broad daylight with the sun directly on her/him.
Those outdoor portraits tend to either have the subject in shade, with the background in bright daylight, or their back to the sun. This way you immediately gain 4 stops to play with for a 'regular' exposure (depending if they are in the shade or back to the sun). And can add a stop or two for high key.
You can also just switch to manual, and ignore the meter readings. You could also use a slower film. You could also use ND filters but this I would not recommend for portraits as it makes the camera much harder to focus.
When I do this kind of work, I either use the camera in manual mode, or AEL and take a spot meter reading and hold it.
 

bain

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Welcome to the 645 Pro TL club!

Firstly, I love this system, but I barely see the need to shoot wide open with these lenses.
(I'm assuming you're using the common 80mm 2.8)
If you're a quick shooter, which it sounds like you are, shooting at f/2.8 without a tripod I've found will almost guarantee that I'll miss focus just enough to irk me. Shooting at f/4 or even 5.6 will still have great fall off and but obviously keep it easier to hit focus.

Also, that 2nd dial on top of the prism will allow you to keep your ISO set correctly and trick the meter into under/over exposing by up to 3 stops, or as finely as 1/3rd of a stop increments. This keeps it easy to remember just how much you're over/under exposing without having to do all the maths. And finally, don't forget to make use of the spot (SP) meter function on the prism finder! that will make your shadowy metering reading technique... whatever you're doing... easier.

Whatever you do just enjoy shooting! and if you use a lab don't go cheap on the scans! Shooting Medium Format is pointless if you only have 10mb files in the end.
 

mynewcolour

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Others have mentioned it ... you can use ND filters.

Usually better* is to stop down to f4, move into half or full shade or shoot when the sun is lower.

*this is a creative call really.
 

Pablo Villegas

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There’s nothing wrong with your settings or your theory.

The finder is faulty, remove it, and clean the contacts on the finder and the camera. All of them and reinsert it.

That just happened today on one I bought online. I thought it was faulty, but it’s the contacts.

It would work with the crank and lot the motor grip. And then the opposite, when that happens I just remove it and clean the contacts and it works. It gives a correct reading also. Just checked it with my handheld meter.
 

LensGrinder

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I’m new here, I’m an old timer renewing my interest in film cameras. This summer I purchased a Mamyia ProTL with the FE401 finder an a 55-110mm zoom. Yup it’s heavy n awkward.

The Meter was working fine when it was unboxed several months ago, and the last time played with it (I’ve not shot film yet because I’m still acquiring darkroom supplies. I used to shoot film as a teen, but can’t find much of the old tools)

Tonight I have same symptoms as the thread author. All shutter speed and aperature invoke a flashing “OVER” at top left of view finder. It’s very possible contacts could be bad. It really hasn’t been used much yet.

What or where can I find a procedure for cleaning contacts? Thanks
 

MattKing

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Welcome to Photrio.
First, I would suggest new batteries. Buy more than one, because most of us have had experiences with apparently new batteries being partially discharged right out of the package. The silver-oxide versions are preferable, but the alkaline versions are cheap and relatively easy to get. I wouldn't leave them in though if I wasn't using the camera for a while.
For cleaning contacts, I start first with just rubbing them with a clean, soft cloth. Next I try a clean, soft pencil eraser followed by the cloth.
 

Sirius Glass

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I use a Hasselblad which is similar to your camera. From the start I did not like the left right reversal and put on a focusing prism just as you have. I find it works for me like a large 35mm camera. Very comfortable to use.

If you want to shoot with the lens wide open or more open, rather than over expose the film, put a Neutral Density filter on your camera such as a ND2 or ND3. I think that the ND3 will get to wider opening with ISO 400 film shot at ISO 400, such as Portra 400. On a bright sunny day instead of f/16 at 1/500 second, a ND3 would give you f/5.6 at 1/500 second. An overcast day you get you f/2 at 1/500 second. OR use an ISO 160 film like Portra 160 on a bright sunny day instead of f/8-f/11 at 1/500 second, a ND3 would give you f/2.8-f/4 at 1/500 second. An overcast day you get you f/2-f/1.2 at 1/500 second.








Welcome to APUG Photrio!!​
 

LensGrinder

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Thanks for the reply’s.
PabloV and MattK understood my issue and thank you. One worries allot when an expensive piece of gear doesn’t work like it should

Night before last when I published the question I used a modified Pablo technique and I just rubbed a finger on all contacts as a … well let’s just try this… and it worked. The “OVER” stopped and metering resumed. Some of the contacts are metal nubs …some are spring loaded pins. I think it was contacts on the film back that was the trouble maker. So like what PabloV says “do all the contacts”.

I know my finger was the wrong tool for the job, right now I’m happy that it’s resumed functioning two days in a row.

That said, I should do a proper contact cleaning. Does anyone use an electrical contact cleaner like DeOxit or WD 40 has an electrical contact cleaner (it’s different that just the generic WD40, I think is called Specialist???) on a cloth. I’m happy with just a dry rag because that works in the field. This camera has not had a deep clean since unboxing.

A BIG Thank You to this Forum.
 
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