[germar]

It seems to be an accepted truth that you WANT a 6x7 series camera with MLU, and the price of non-MLU bodies is significantly lower than those with it. But what are the real world results of not using mirror lock up?

I absolutely do not dispute it's value, as Pentax spent a lot of development time putting the feature in. But I've only read passing comments about "you need this on certain tele shots" but not much else. Is it only a feature useful for telephoto work? What is it's impact on wide angle shots, or long exposure work?

Can someone post an example of a photo that was impacted by not using MLU?

I'm trying to understand this feature and use it correctly.

Thanks in advance for your opinions.

Germar

[Dario79]

As I understand MLU is useful on long exposures and extrem telephoto because mirror it self can create vibration when it slaps during proces of taking photograph. So when you lock up the mirror you eliminate even those minor vibrations and that gives us sharper pictures. Please corect me if I'm wrong.

[Digitalis]

The mirror isn't the only problem with the Pentax 67. Mirror lock up is most useful around the 1/30th to 1" shutter speed ranges - where the camera is most vulnerable to vibrations. Just using MLU sometimes simply isn't enough, the shutter has considerable amount of mass as well. Shutter bounce is problematic on the Pentax 67, it commonly visible at the 1/8th to 1/2" shutter speeds. To reduce it using a tripod that weighs at least twice the weight of the camera/lens combo you plan on using helps keep it under control.

[carrrlangas]

I found the best explanation in this article:

Common Obstacles in Night Photography

Look at the "influence of MLU" section. I guess MLU is even more important in bigger formats. (bigger mirror -> stronger/longer vibration)

[blackcloudbrew]

carrrlangas - that's an excellent reference! +1

[carrrlangas]

carrrlangas - that's an excellent reference! +1

Glad it helps! check out that web. The tutorials are great! I think I got the best info from it. And it covers lots of topics..

[tuco]

I'd bump up Digitalis's shutter range to 1/60 in practice. Those shutter speeds I'm typically using a tripod too. For long exposures I'd think any vibration is too short of a duration compared to the overall exposure to be recorded.

[gofour3]

I would recommend skipping the older 6x7 cameras and going for a 67 or 67II. These two models both have MLU and you will have a better chance of getting a clean body with no issues.

Phil.

[Digitalis]

For long exposures I'd think any vibration is too short of a duration compared to the overall exposure to be recorded.

that is accurate for anything over 5 seconds - anything under that and vibrations can still be an issue.

[desertscape]

If you are only going to own one P67, I suggest getting the MLU type. If you plan on owning two or more, the non MLU can work in certain situations ( like handheld work and wide lens work on a tripod). Although I have used mine successfully for long exposure shots, the MLU version is better for this. The shutter causes more problems than the mirror actually.

[Silent Street]

There is never an exposure made on my 67 when mirror lock-up is not engaged. I exercise great care with each and every one of my exposures and it shows with zero vibration visible through the use of a tripod and mirror-lock up, even down to 45 second exposures. Mirror lock-up is just one problem you are able to deal with: the slap of the mirror. The second, which cannot really be dealth with other than solidly bracing the camera, is the shutter whack.

Remember that on all 67 bodies mirror lock-up is a drain on the battery; compose, focus, meter, mirror-up then shoot; leaving the mirror up will flatten the battery in around 4-5 hours.

[Digitalis]

The shutter causes more problems than the mirror actually.

+1 this.