100-300 Panasonic not as Sharp as i wanted

AllFlawed wrote:

jeffharris wrote:

AllFlawed wrote:

jeffharris wrote:

spike29 wrote:

F7.1 if i need the shutterspeed, f8 for starters and f9/11 for dof need

f9-f11 is squarely in the diffraction zone. Avoid using those, unless loss of sharpness and detail is what you’re looking for.

No diffraction below this? Instant onset of diffraction effect at f9? What exactly does diffraction zone mean?

Generally, after f5.6 diffraction begins. After that it gets worse the smaller the aperture used. Once you’ve passed the point where diffraction starts, I’d call that the diffraction zone.

That’s pretty simple, no?

If there’s a more official designation, enlighten me.

People do dig deep looking for diffraction sometimes and the blur from diffraction is a lot less than with anything but the subject itself being plain out of focus with a wider aperture. I think the diffraction side of things does overly scare people off from closing up the aperture when it is needed.

It depends on the subject and the lens, too.

When I first got my GH2 and 7-14mm f4 I was out shooting some landscapes… water, trees, etc.… and not being familiar with the camera, was relying on the camera to make exposure decisions. There were a bunch of shots at f9, f10, & f11 where foliage detail was obliterated using those apertures. I decided to go back to basics and shoot in M mode.

bclaff wrote:

Eric Nepean wrote:

...

Consider this:

Diffraction is caused by light passing through a hole, and the effect is proportional to the hole size over the wavelength of the light. The limiting hole in a well desgned lens is the aperture mechanism.

But we don't really know how big the aperture is - not easily

We see the entrance pupil, which is the aperture seen through all the optical elements in front of the aperture. For telephoto lenses, this is usually slightly smaller than the diameter of the front optical element. (clearly not the case for the 12-100/4 however)

The sensor "sees" the exit pupil, which is the aperture seen through all the optical elements behind the aperture. The diffracted light is also affected by the optical elements behind the aperture, as is the light which is not diffracted.

The front focal length is often different than the rear focal length.

I think we best post this in the Photo Science and Technology forum.

Focal length is focal length regardless of front/rear, you may be thinking of a different distance.

In your Optical bench you report a quantity called "Back Focal Length"

Perhaps I was imprecise in using "rear" instead of "back"

Don't have much time for research to day. but Wikipedia defines

• Front focal length (FFL) or front focal distance (FFD) (sF) is the distance from the front focal point of the system (F) to the vertex of the first optical surface (S1).[1][2]
• Back focal length (BFL) or back focal distance (BFD) (s′F′) is the distance from the vertex of the last optical surface of the system (S2) to the rear focal point (F′).[1][2]

True, this is only Wikepedia, but the references quoted seem pretty solid.

If there is a reason to distinguish FFL from BFL, that would only be because they are not necessarily the same value. At least one of them will sometimes not be the same as the Focal length printed on the lens and stated in the specifications.

I recall seeing an equation relating focal length to BFL and FFL to magnification.

In any case, the ratio of exit pupil size over entrance pupil size is called pupil magnification. And this does affect diffraction (and depth of field and other things. It's often overlooked.)

(I followed your recent post on the exit pupil size and relationship depth of field  and the ensuing discussion)

Even if the magnification is 1, is the Aperture diameter the same as the entrance pupil diameter? Seems unlikely with those optical elements in front of the aperture.

It wouldn't maater, except that we derive the diffraction based on  the ratio of aperture diameter to the wavelength, and magniication of of the aperture isn't going to scale the wavelength.

We don't often know this value but you can get a sense by visual inspection.

In general pupil magnification is around 1 for lenses with and angle of view of about 30 to 50 degrees.
Wide angle lenses can have pupil magnifications that are quite high.
Telephoto lenses are usually below 1.

I'm currently working on a survey article regarding pupil magnification across a large number of lenses. Stay tuned.

jeffharris wrote:

spike29 wrote:

F7.1 if i need the shutterspeed, f8 for starters and f9/11 for dof need

f9-f11 is squarely in the diffraction zone. Avoid using those, unless loss of sharpness and detail is what you’re looking for.

The majority of M4/3 lenses hit optimum sharpness at f4 or f5.6.

Of course at 100mm f7.1 or f6.3 is fine.

Actually, f7.1 is ideal, regardless of zoom range used.

It's al about Dof related sharpnesfield and AF point placement.

At f7.1, your equivalent f-stop is f14.2, so depth of field really isn’t (much of) an issue.

When shooting with the 100-300mm, the simplest way to ensure optimum image quality, is to simply set it at f7.1 and leave it there. Adjust shutter speed and ISO accordingly.

If you look at thread after thread in the forum (rotten search engine be damned), you’ll find the same technique recommended over and over. I was skeptical at first, but in real-world use, it proved to be accurate.

with the Oly 75-300 the ideal f stop seems to be f/9.....probably because it's a slower lens than the Panny 100-300.....max f stop at 300mm is f/6.7 on the Oly while it's f/5.6 on the Panny.  On these long zooms it is often recommended that the sweet spot for f stop is 1 stop slower than the max, so f/9 for the 75-300 would be along those lines.

AllFlawed wrote:

jeffharris wrote:

spike29 wrote:

F7.1 if i need the shutterspeed, f8 for starters and f9/11 for dof need

f9-f11 is squarely in the diffraction zone. Avoid using those, unless loss of sharpness and detail is what you’re looking for.

No diffraction below this? Instant onset of diffraction effect at f9? What exactly does diffraction zone mean?

I would though diffraction increases as aperture decreases and pin hole sharpening goes the other way and there is just an optimum point somewhere rather than any specific zone. Also given that the aperture will vary at different focal lengths for the same f number, with a different proportion of total light running over the aperture blades, the actual optimum points expressed in f numbers for such a long zoom lens seems difficult to understand,

The majority of M4/3 lenses hit optimum sharpness at f4 or f5.6.

Of course at 100mm f7.1 or f6.3 is fine.

Actually, f7.1 is ideal, regardless of zoom range used.

It's al about Dof related sharpnesfield and AF point placement.

At f7.1, your equivalent f-stop is f14.2, so depth of field really isn’t (much of) an issue.

When shooting with the 100-300mm, the simplest way to ensure optimum image quality, is to simply set it at f7.1 and leave it there. Adjust shutter speed and ISO accordingly.

If you look at thread after thread in the forum (rotten search engine be damned), you’ll find the same technique recommended over and over. I was skeptical at first, but in real-world use, it proved to be accurate.

well put!  for the Oly 75-300 the common wisdom seems to be that the sweet spot is one stop below max f stop....and since max is f/6.7 at the long end, f/9 would follow that rule, and I did about 64 GB worth of testing and that's what I confirmed.

bclaff wrote:

Eric Nepean wrote:

...

Consider this:

Diffraction is caused by light passing through a hole, and the effect is proportional to the hole size over the wavelength of the light. The limiting hole in a well desgned lens is the aperture mechanism.

But we don't really know how big the aperture is - not easily

We see the entrance pupil, which is the aperture seen through all the optical elements in front of the aperture. For telephoto lenses, this is usually slightly smaller than the diameter of the front optical element. (clearly not the case for the 12-100/4 however)

The sensor "sees" the exit pupil, which is the aperture seen through all the optical elements behind the aperture. The diffracted light is also affected by the optical elements behind the aperture, as is the light which is not diffracted.

The front focal length is often different than the rear focal length.

I think we best post this in the Photo Science and Technology forum.

Focal length is focal length regardless of front/rear, you may be thinking of a different distance.

In any case, the ratio of exit pupil size over entrance pupil size is called pupil magnification. And this does affect diffraction (and depth of field and other things. It's often overlooked.)

We don't often know this value but you can get a sense by visual inspection.

In general pupil magnification is around 1 for lenses with and angle of view of about 30 to 50 degrees.
Wide angle lenses can have pupil magnifications that are quite high.
Telephoto lenses are usually below 1.

I'm currently working on a survey article regarding pupil magnification across a large number of lenses. Stay tuned.

Bill, I hope you do one for the Oly 75-300 lens.  I did 64 GB worth of testing and found f/9 to be the "sweet spot" at the long end.  It goes along with the general wisdom that the ideal f spot on these long teles is one f stop slower than max (which is f/6.7 on that lens.)

bclaff wrote:

Eric Nepean wrote:

bclaff wrote:

Eric Nepean wrote:

...

Consider this:

Diffraction is caused by light passing through a hole, and the effect is proportional to the hole size over the wavelength of the light. The limiting hole in a well desgned lens is the aperture mechanism.

But we don't really know how big the aperture is - not easily

We see the entrance pupil, which is the aperture seen through all the optical elements in front of the aperture. For telephoto lenses, this is usually slightly smaller than the diameter of the front optical element. (clearly not the case for the 12-100/4 however)

The sensor "sees" the exit pupil, which is the aperture seen through all the optical elements behind the aperture. The diffracted light is also affected by the optical elements behind the aperture, as is the light which is not diffracted.

The front focal length is often different than the rear focal length.

I think we best post this in the Photo Science and Technology forum.

Focal length is focal length regardless of front/rear, you may be thinking of a different distance.

In your Optical bench you report a quantity called "Back Focal Length"

Perhaps I was imprecise in using "rear" instead of "back"

Don't have much time for research to day. but Wikipedia defines

• Front focal length (FFL) or front focal distance (FFD) (sF) is the distance from the front focal point of the system (F) to the vertex of the first optical surface (S1).[1][2]
• Back focal length (BFL) or back focal distance (BFD) (s′F′) is the distance from the vertex of the last optical surface of the system (S2) to the rear focal point (F′).[1][2]

True, this is only Wikepedia, but the references quoted seem pretty solid.

If there is a reason to distinguish FFL from BFL, that would only be because they are not necessarily the same value. At least one of them will sometimes not be the same as the Focal length printed on the lens and stated in the specifications.

I recall seeing an equation relating focal length to BFL and FFL to magnification.

FFL and BFL are of no practical use in ordinary photography. They are optical design values.

In any case, the ratio of exit pupil size over entrance pupil size is called pupil magnification. And this does affect diffraction (and depth of field and other things. It's often overlooked.)

(I followed your recent post on the exit pupil size and relationship depth of field and the ensuing discussion)

Even if the magnification is 1, is the Aperture diameter the same as the entrance pupil diameter? Seems unlikely with those optical elements in front of the aperture.

No because pupil magnification is exit over entrance and has nothing to do with the physical diaphragm. However, see below.

It wouldn't matter, except that we derive the diffraction based on the ratio of aperture diameter to the wavelength, and magnification of of the aperture isn't going to scale the wavelength.

The Airy disc that originates at the physical diaphragm is projected onto the image plane as a different size. That size is not pupil magnification per se but as you allude to above exit pupil over diaphram.

...

Bill, with telescopes and eyepieces the airy disc is used to collimate and determine optical quality of the instruments being used. Can this be used with camera lenses too to determine their worthiness for astrophotography?  Is that why primes are better for this usage?

jeffharris wrote:

AllFlawed wrote:

jeffharris wrote:

AllFlawed wrote:

jeffharris wrote:

spike29 wrote:

F7.1 if i need the shutterspeed, f8 for starters and f9/11 for dof need

f9-f11 is squarely in the diffraction zone. Avoid using those, unless loss of sharpness and detail is what you’re looking for.

No diffraction below this? Instant onset of diffraction effect at f9? What exactly does diffraction zone mean?

Generally, after f5.6 diffraction begins. After that it gets worse the smaller the aperture used. Once you’ve passed the point where diffraction starts, I’d call that the diffraction zone.

That’s pretty simple, no?

If there’s a more official designation, enlighten me.

People do dig deep looking for diffraction sometimes and the blur from diffraction is a lot less than with anything but the subject itself being plain out of focus with a wider aperture. I think the diffraction side of things does overly scare people off from closing up the aperture when it is needed.

It depends on the subject and the lens, too.

When I first got my GH2 and 7-14mm f4 I was out shooting some landscapes… water, trees, etc.… and not being familiar with the camera, was relying on the camera to make exposure decisions. There were a bunch of shots at f9, f10, & f11 where foliage detail was obliterated using those apertures. I decided to go back to basics and shoot in M mode.

But thats a much faster lens than these long teles, where one stop below max aperture is often recommended.  Thats how I got f/9 at 300mm with my 75-300mm lens which is f/6.7 max at the tele end.  I confirmed it after doing about 64 GB worth of testing.....f/9 seemed to produce the most detailed images.

Wigelii wrote:

AdamT wrote:

Wigelii wrote:

AdamT wrote:

Nothing wrong with those whatsoever for a lens which is a 1st generation design and can be bought for as little as just over £200 secondhand ......

I`ve seen worse examples from the expensive PanaLeica 100-400 (which has a very Polarised reputation)

Is the 100-400 not worth buying?

opinion on whether its worth the money is polarised also whether or not its sharp at 400mm wideopen given that it`s already 1/3 of a stop too slow at F6.3 (even F5,6 is starting into diffraction) and not exactly cheap at £1100

I have no personal opinion on it, I live in the UK where its dull 90% of the time, F2.8 rules here - LOL

Same here in Belgium (that's in Europe 😉)

Is it now?  

But I have to disagree; as so-so the weather in Belgium is, my experience of the UK is worse. Beer not as great either but they make it up with the  Scottish whisky...

Wigelii wrote:

spike29 wrote:

The one with no goverment?

We ,north of you , offer a change to be free and be "brabant zuid" 😂

I think that's a very good idea. Unfortunately there are not so many people in Belgium that like your food and your beer, so I am not sure we'll find enough people in favour😀

And by the way, this country seems to work better without government than with a government. Maybe we just send our politicians your way and we stay independent (well.... servants of France and Germany)

Hum, might be a good idea that.... But then we stay servants - or more so - to Trump Country...

Or you live in the south part then your eh bound to a larger type of Europain country.

Carlo11 wrote:

Thanks for quick and positive respons. Havn’t had such a long lens before. Didn’t know What to expect . Glad to Hear There is nothing wrong with The lens. I Will be happy with it now thanks to you all!!!

it’s not The 1st generation, its The mark ii (480 euro’s)

i Will try to shoot raw! GOOD TIP. Havn’t done That before. I Will find Out.... lots of tips on this forum i suppose.

The G85 is oké, but maybe i Will look for a g9. Pinpoint focussing Will be more accurate i think.

one thing i noticed is the Need for relative fast shutter speeds with these subjects. Stabilisation is useless with moving animals. So with low light it can be difficult to get Sharp images.

Yes, technique is everything with this lens. Although the MkII improved the OIS, the weather sealing and autofocus, optically it is the same as the original 100-300 from 2010. So on a good,recent camera, I would suggest shooting at 800 ISO most of the time and F7.1 or F8 at the long end. Notice that your 3rd shot at 800 ISO seems the sharpest...

BTW, your G85 should provide you with pinpoint focusing as my older G3 did that already. And also BTW, I seldom use pin-pont but rather the smaller focusing "box" as it provides more area for the contrast-detect focusing to work on.

pannumon wrote:

Carlo11 wrote:

Thanks for quick and positive respons. Havn’t had such a long lens before. Didn’t know What to expect . Glad to Hear There is nothing wrong with The lens. I Will be happy with it now thanks to you all!!!

it’s not The 1st generation, its The mark ii (480 euro’s)

i Will try to shoot raw! GOOD TIP. Havn’t done That before. I Will find Out.... lots of tips on this forum i suppose.

The G85 is oké, but maybe i Will look for a g9. Pinpoint focussing Will be more accurate i think.

one thing i noticed is the Need for relative fast shutter speeds with these subjects. Stabilisation is useless with moving animals. So with low light it can be difficult to get Sharp images.

If you have someone to give you good advice, you will get better results by using raw with a half day training, but that is very very positive thinking. Raw simplifies things, but developing your own workflow takes some time. Also, raw development won't do miracles, but saving the results of careful analysis of lens/shutter speed/ISO combinations makes it quick and easy in the future. In principle, but I think it's also good to understand what's going on with the processing.

I beg to differ. Since I crossed from the 36 exposure 35mm film era to the "all-you-can-eat" digital era, I found that the number of pics I took on any given trip was mind-boggling. Just the classifying and renaming of the pics takes days. If I were to shoot everything in RAW + JPEG, it would take me years of PP per month of travel. Even doing RAW on very specific venues is almost overwhelming and defeats the purpose of having fun with your photography. Now ideally, if I could get back to the time when every shot - out of 36 - counted, then, yeah, I'd be a RAW fan. With 3000 pics?

For static subjects there is no reason to upgrade to G9. G85 is already really good. G9 is better for sure, but it's also larger and heavier and more expensive.

bclaff wrote:

OutsideTheMatrix wrote:

...

Bill, I hope you do one for the Oly 75-300 lens. ...

Sure. If I ever locate an appropriate patent.

I dont know how to find that either, I was hoping it was in the EXIF info somewhere.

rashid7 wrote:

OutsideTheMatrix wrote:

kbouk wrote:

I have the same lens, you have to be careful when you have long distances targets , use 280mm rather 300mm and crop after or if you use 300mm close the aperture 1-2 clicks. Do a comparison to see how your lens copy behaves.
No problem at 300mm with open aperture when the target is close enough. From 100-240mm my copy gives very good results wide open. I’m very satisfy with lens performance and I have compare it with more expensive lenses (old 50-200/2.8-3.5 SWD, LEICA 200/2.8 with 1.4X TC)

I like the closing aperture trick (for max resolution too). I find on the Oly 75-300 you need to close it down to f/9 for best results. Have you done tests with the Panny, and what did you find was its best aperture setting at the tele end? What did you need to close it down to to completely remove shadows from the corners? With the 75-300 I needed to go all the way to f/10 to completely remove shadows, but the best resolution was actually at f/9 so I keep it there, getting a slight amount of corner shadowing.

be careful w/ m4/3 lenses. Closing down more than 1 stop seldom works best. (even aside from the reduction of light!)

Central sharpness almost always suffers! And you need every bit of light u can get from a long lens. F7.1 would be the smallest f-stop to use on 100-300, and only at 300mm in good light

unfortunately the Oly 75-300 lens is rather slow and max aperture is only f/6.7 at 300mm, so f/9 ends up being just about 1 stop less.

jeffharris wrote:

spike29 wrote:

F7.1 if i need the shutterspeed, f8 for starters and f9/11 for dof need

f9-f11 is squarely in the diffraction zone. Avoid using those, unless loss of sharpness and detail is what you’re looking for.

The majority of M4/3 lenses hit optimum sharpness at f4 or f5.6.

Of course at 100mm f7.1 or f6.3 is fine.

Actually, f7.1 is ideal, regardless of zoom range used.

It's al about Dof related sharpnesfield and AF point placement.

At f7.1, your equivalent f-stop is f14.2, so depth of field really isn’t (much of) an issue.

When shooting with the 100-300mm, the simplest way to ensure optimum image quality, is to simply set it at f7.1 and leave it there. Adjust shutter speed and ISO accordingly.

If you look at thread after thread in the forum (rotten search engine be damned), you’ll find the same technique recommended over and over. I was skeptical at first, but in real-world use, it proved to be accurate.

Ditto! Mine is set at F7.1, 800 ISO, grain be damned !