Focusing with the IQ180

[vjbelle]

I have found that a combination of the focus overlay and a 3X MF loupe to be the fastest and most accurate focus workflow. The focus mask, for me, is just too unreliable to be used exclusively - I have seen images obviously out of focus showing an in-focus line with the mask. An image at 100% on the back and viewed with a loupe can pinpoint the focus area accurately and repeatidly. A combination of the two makes a lot of sense to me..... however I think that ultimately verifying the focus with the loupe is necessary for complete accuracy...... other than its a pita to carry around. So, for me, compose - rough focus/auto focus at 5.6 - check focus mask - verify focus line with loupe - make adjustments - verify with focus mask - double check with loupe - take image at desired apeture. The loupe can't be fooled!

Victor

 

[Terry]

What sensitivity do you set the focus mask to?

 

[dougpeterson]

One of the best parts of the focus mask is it's ability to show you progressions

In other words for checking exact focus position it gets a B+ from me. Darn good but far from perfect. For observing the focus move and/or swing/tilt as you rack focus or apply movements it gets an A.

As Terry says the sensitivity you set it to is critical. The back doesn't know if you're looking for 6-foot-detailed-landscape-prints levels of detail/focus or wide-open-portrait-with-old-soft-lens levels of detail/focus.

If you set the focus mask to a high value (less sensitive) it will very rarely indicate a false-positive. Though of course some times the image will be in focus and it won't be able to confirm it for you.

Doug Peterson (e-mail Me)
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[vjbelle]

What sensitivity do you set the focus mask to?

Terry,

The sensitivity isn't the issue. As I understand it the focus mask checks for contrast variations. So....the image could be slightly out of focus but have enough contrast variations that it would trigger the focus mask to say something was in focus when, in fact, it wasn't. My loupe verification workflow method eliminates this error. At 100% the image through the loupe is so clear that its almost impossible, unless REALLY vision impaired, to not see where the focus point is in the image.

Victor

 

[tashley]

Terry,

The sensitivity isn't the issue. As I understand it the focus mask checks for contrast variations. So....the image could be slightly out of focus but have enough contrast variations that it would trigger the focus mask to say something was in focus when, in fact, it wasn't. My loupe verification workflow method eliminates this error. At 100% the image through the loupe is so clear that its almost impossible, unless REALLY vision impaired, to not see where the focus point is in the image.

Victor

Hmmm...which loupe do you use? And is it really better than just zooming in further?

 

[dougpeterson]

Hmmm...which loupe do you use? And is it really better than just zooming in further?

I strongly suspect the answer to that question depends on how bright it is outside and how good your eyes are.

The IQ screen is very clear, but in glare from direct sunlight it (like even an iPhone 4) benefits from the shading inherent in a loupe (or a hood). And a loupe can be set with a diopeter adjustment for viewing without glasses (obviously depending on the eyes and the loupe).

Doug Peterson (e-mail Me)
__________________

Head of Technical Services, Capture Integration
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National: 877.217.9870 *| *Cell: 740.707.2183
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[Guy Mancuso]

Aperture, diffraction , setting and contrast all play a role in Focus mask. Like if your in a foggy day forget it, you may not even see it. The more light the better it sees just like us. It's not full proof but 100 percent view would be the the better answer for sure. Question is do you need a loupe, I say no but certainly would not hurt at all and would actually help. If it helps you than by all means use one. There are no rules here do whatever is going to work best for you and your style of shooting. For me i don't need a loupe and i view focus mask as a confirmation tool not a absolute measurement. If i really want to know i will zoom in to 100 percent but I like what the focus mask does and that is create speed in the confirmation of focus. Its up in 2 seconds on the 160. That tells me a lot right away

 

[Jack]

Terry,

The sensitivity isn't the issue.

Yes it is. Try setting it higher, like to 50 and report back. 50 will rarely generate a false positive unless your lens is diffraction limited, in which case try 75 or 80 and I guarantee you'll have no false positives -- but 75 may not show any indication on the best focus for your poorer lenses. It's a tool, not a perfect tool , but a very good tool, and you need to spend the time to learn how to use it...

 

[Christopher]

I think it would be great to have some presets. I don't like to change the settings with a slider everytime I change from f4 to f16 or from one lens to another. I think 3-5 presets, which one can set up would be great.

 

[Jack]

I think it would be great to have some presets. I don't like to change the settings with a slider everytime I change from f4 to f16 or from one lens to another. I think 3-5 presets, which one can set up would be great.

Good idea! I am regularly using 40 for my Schneider LS lenses, but need like 60 for my 40HR-W.

 

[vjbelle]

Hmmm...which loupe do you use? And is it really better than just zooming in further?

Well, that really will be up to you! I prefer to use a loupe and find it to be fool proof. I happen to use a Schneider that has a 3X magnification but I think any of the LCD loups would work just fine.

Victor