Got it! Now some questions (Mamiya 645 Pro)

So, got me a Mamiya 645 Pro with 2 backs, winder, prism and 2 really nice lenses the 55mm f2.8 & 110mm f2.8 therefore HNCD to me!!!!

Some initial questions pls:

1. I sometimes find It difficult to distinguish the metering numbers through the prism. I always use my 20/20 eye and even though most of the times they are crystal clear sometimes they seem to be out of focus. Any ideas?

2. Lens diffraction. Never had a MF prime so not really sure if they suffer as much and from what fstop. Pls advice.

3. What kind of strap do you use? The original is quite expensive any cheaper alternatives?

4. What is the procedure in order to change a back mid-roll? I plan on having B&W in one and color in the other (yeah big surprise) so if possible pls let me know the steps with the winder in place.

Many thanks in advance!

hoakin1981 said:

1. I sometimes find It difficult to distinguish the metering numbers through the prism. I always use my 20/20 eye and even though most of the times they are crystal clear sometimes they seem to be out of focus. Any ideas?

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I've got crap eyesight but even with glasses or contacts I haven't had a problem reading them, so can't help with this one. You might be able to get a diopter adjustment that fits the eyepeice, it looks like it takes one.

2. Lens diffraction. Never had a MF prime so not really sure if they suffer as much and from what fstop. Pls advice.

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every lens will be different. Never worried about this myself, I use what I need and accept what I get.

3. What kind of strap do you use? The original is quite expensive any cheaper alternatives?

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don't have a strap. Haven't dropped it yet

4. What is the procedure in order to change a back mid-roll? I plan on having B&W in one and color in the other (yeah big surprise) so if possible pls let me know the steps with the winder in place.

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You take the darkslide out of the holder in the filmback door (assuming that's where it is while you've been using that back) and put it in the slot between filmback and camera then remove the back by pushing the release button while sliding the lock button (I use my thumb to do both at once). Wack the other back on before you poke something thru the shutter

hoakin1981 said:

So, got me a Mamiya 645 Pro with 2 backs, winder, prism and 2 really nice lenses the 55mm f2.8 & 110mm f2.8 therefore HNCD to me!!!!

Some initial questions pls:

3. What kind of strap do you use? The original is quite expensive any cheaper alternatives?

Many thanks in advance!

Click to expand...

Did you get a power winder or the crank winder? I have a very thin strap which is not very useful except for briefly resting the camera when I need to use my hand for something. I normally just carry it with the power winder, partly because of my small strap and partly because it doesn't really hang well due to its bulk. If you want a wider strap that is cheaper than a Mamiya one, look at the Op/Tech straps.

According to the DoF calculator Dead Link Removed, blur due to diffraction only starts to kick in at f22. I use 0.02mm as the 35mm equivalent CoC, a bit more critical than the traditional 0.03mm. If you use 0.01mm for the 35mm equivalent CoC, then blur due to diffraction starts to become dominant at f11. All related to the 645 format and regardless of the focal length of the lens.

For the strap, I use a wrist strap that came with the camera. It's connected to the right side of the camera where the winder is. I normally hold the camera at the winder with the strap around the wrist. Works well for me. I'm not a fan of dangling cameras on a neck strap.

Diffraction is rarely an issue for me. If you have a situation where depth of field doesn't really matter a lot, and you can choose any aperture, something around f/8 or f/11 will probably give you optimum results. There are lens tests out there somewhere on the internet, but you may have trouble finding them for the 110 mm lens.

I use a Mamiya strap with a hand crank or the winder N. The strap itself may be over-priced, but the Mamiya clips that work with the camera are worth the price. You need something special, because the interaction between the clip and the winder is important - the winder can get in the way.

As to #4 - remember the holders keep your frame count, not the winders. Just don't forget the dark slide!

If the 645 uses the same strap as the RB67 Optech makes a strap for about $20.00