[toni-a]

Among first things we learned is shutter speed at least 1/focal, that was in film days when rare looked at their pictures zoomed 200% on a screen.

We know that rule is approximative and is not enough if you want ultimate sharpness.

Now let's talk about some new lenses like sigma 135mmf1.8 handheld at 1/200s how close would it get you to lab MTF values ? Will we be able to exploit its details resolution potential?

How much in real world, real life settings do you think we can exploit lenses potential?

[wim]

Hi toni-a,

 

It really depends on what you;d consider enough in resolution.

In order to really maximize the resolution, you'd need total shock, movement and shake free operation, which effectively is only possible in a lab environment.

 

To get as close as is possible shooting handheld, you'd need a much higher shutter speed than the 1/FL rule anyway, as that originally was the advice for LF photography, not really for FF photography, although this was partially inspired by people etc. moving as well during exposure.

 

In addition, it depends a lot on the operator too. Some peoplr are more shake or tremble free than others, so they can get away with longer shutter speeds.

 

Having said all this, I reckon that if you'd go beyond, say 1/(4*FL), you will not see a lot of improvement anymore, regardless of whether you are in a lab environment or not - providing you are standing still that is . This based on personal experiments.

 

However, the gain over 1/(2*FL) is really very little, to me anyway, so I use whatever I think is appropriate. In the end a photograph is better than none.

 

Oh, all of this of course without taking IS into account. With IS you can get a lot lower, but that still does not help with movement of subjects. I find that with people you need at least 1/100 s, with children often faster shutter speeds, as is the case with (smaller) pets.

 

Do note that (very) high MP counts also add to the equation. A 5Ds or 5DsR requires a much faster shutter speed for optimum sharpness than a camera with half the MP does.

 

In general I think you can say that for MP increase you need an MP factor in shutter speed increase, and the same is probably true for higher resolution lenses. Translated, this means that for a doubling of MPs you'd need a 2x faster shuitter speed, and for a lens that has, say, 1.2x the resolution of a lens youd normally use, you need a 'quadratic increase or 1.4x factor faster shutter speed in addition. Just recommendations, mind you, not a hard and fast rule.

 

HTH, kind regards, Wim

 

[toni-a]

You're 100% correct from a technical point of view, however in the field, in real life how many times you manage to get those shutter speeds at low ISO, I already struggle with my 100mm lens.

Let's talk about a 135mm portrait Lens, how many times do you shoot portraits in bright sunlight ??

Shooting in the shade you need easily ISO 400 to have shutter speed at 1/250 that if you lose the lens wide open.

Using flash you are at the limit of x sync already.

So my point is we won't be able to exploit the potential of super sharp Tele lenses, I am sure sharpness wise, if you use handheld any 135mm lens what will define sharpness is not the lens but the quantity of light available.

Stepped down in the lab they get sharper, try it handheld at 1/300s f1.8 vs 1/150s f2.8 and tell me if it will get any sharper ?

[wim]

Actually, under the same circumstances, everything else being the same, a sharper lens will always provide more sharpness (or resolution if you prefer). Whether you shoot at 1/100s or 1/1000s is immaterial in that case.

 

IOW, it is always worth it from a resolution POV. There are many factors for which it may not be worth it, like weight, size, budget/price, etc.

 

As to higher iso, if you really still care about the difference between, say 100 iso and 800 iso in digital, you should only be using a very sturdy tripod. People talk about noise as if it is a zillion times worse: it actually isn't. And compared to film it is completely laughable to worry about noise up to 6400 iso at least, and that is taking 7 year old cameras into account too..

 

As to x-sync, sorry, but if you use flash you will in principle always have a sharp image, as flash duration is very short, unless you use it purely as fill-in flash.

 

Funnily enough, I never struggle - I use whatever iso is required for a certain shooting situation. That has nothing to do with sharpness, unless you get to really high noise levels, enough to diminish or obliterate sharpness.

 

As to 1/300s with F/1.8 vs 1/150s at F/2.8: whether it gets sharper depends. How much DoF do you need to get the everything you want in focus? How much sharper is the lens at F/1.8 vs F/2.8? Is that what yoiu are looking for in your final image?

 

You were talking about getting the most sharpness out of it, and in that case it requires certain steps and procedures.  If you do not intend to follow those, the benefit is still there, but it will not be maximum sharpness. BTW, you NEVER get close to lab MTF values, unless you do lab testing.

 

I don't see your point either. As mentioned, a sharper lens will always give sharper images provided the circumstances stay the same, so you do benefit from sharper glass. Quantity of light has nothing to do with it. It si about the same circumstances.

 

The real question is whether you personally will benefit enough from it to make it worthwhile to you. For me personally it isn't, to be very honest. I own a 135L, and that lens is very very sharp from wide open, it renders beautifully, and is not terribly heavy, and according to lab tests the Sigma is only marginally better. In short, I will not "upgrade".

 

Kind regards, Wim

[toni-a]

I don't see your point either. As mentioned, a sharper lens will always give sharper images provided the circumstances stay the same, so you do benefit from sharper glass. Quantity of light has nothing to do with it. It si about the same circumstances.

 

The real question is whether you personally will benefit enough from it to make it worthwhile to you. For me personally it isn't, to be very honest. I own a 135L, and that lens is very very sharp from wide open, it renders beautifully, and is not terribly heavy, and according to lab tests the Sigma is only marginally better. In short, I will not "upgrade".

 

Kind regards, Wim

 

While I didn't want to go into the details, my point is that handheld you won't in most cases exploit the full potential of a lens, unless you are in ideal conditions. The influence of poor lighting on image quality handheld, is greater  than lens quality  itself.

 

Aside that I totally agree with you "marginally better in lab tests" doesn't really mean any difference in quality would be noticeable on prints.

[wim]

While I didn't want to go into the details, my point is that handheld you won't in most cases exploit the full potential of a lens, unless you are in ideal conditions. The influence of poor lighting on image quality handheld, is greater  than lens quality  itself.

 

Aside that I totally agree with you "marginally better in lab tests" doesn't really mean any difference in quality would be noticeable on prints.

 

As to your first point: that is true indeed, with any camera, any lens.

 

As to seeing differences in print: I am sure you will see more difference from a camera with 50 MP vs a camera with 25 MP, using the same lens, in print, than from a lens wihich is marginally better. What a lot of people still do not realize, is that sensors are not as sharp, resolution wise, as most (reasonable to good) lenses. As a result, upping sensor resolution provides more detail .

 

Kind regards, Wim

[obican]

Oh btw, all those "shutter shock" and "you can't hold this in your hand and get sharp results" discussion also happened in the film era too. Never with 35mm though. Just search for some Pentax 67 threads  

 

Also, a monopod makes an amazing difference in the field .