Foucs hunting, 100-300 vs 75-300mm?

EarthQuake

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So I have the 100-300mm, and in general I like the lens, but it tends to hunt for focus quite a bit, even in decent light. I'm wondering if anyone has used both the Pana 100-300mm and the Oly 75-300mm can comment on whether the Oly hunts and more/less when focusing?

I originally got the 100-300mm because its a bit faster on the long end, but I wouldn't mind the size/weight savings of the Oly if the focus is a little better. Using an EM1 and EM5 btw.
 

dejongj

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I haven't got both. I have got the 75-300 mark II. It most definitely doesn't hunt. Focus is instant and super fast.

I'm using an E-P5


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Qiou87

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I used the Pana 100-300 on a friends GX7 and I have the 75-300 II on E-M5. The 75-300 on my Olympus body feels faster, and like dejongj I have not encountered any hunting even in poor light at ISO 6400. It just works, and its fast.
 

DennisC

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I normally use the Panasonic Lens on AF-s even for action shots with a pumping shutter action..
Can't say I'd noticed excessive hunting on my G3 or EM10
 

jnewell

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I've used the 100-300mm on several different Panasonic and Olympus bodies. I've never experienced focus hunting. In fact, the lens is fast enough focusing that I haven't missed CAF for shooting crew (rowing) photos.
 

EarthQuake

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Thanks for the comments.

I will clarify a little and say that the hunting is usually with small or distant objects. A distant bird on a blue sky for instance, the 100-300mm has a tough time focusing on it, it shoots back and forth, back and forth instead. Or a bird in a tree, it will sometimes hunt back and forth a couple times before getting a lock. With large objects or high contrast objects it doesn't have much trouble, and is generally very snappy to focus.
 

jnewell

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BIF is challenging even for pro lenses, and neither of the long m4/3 zooms are in that category, unfortunately. You probably know far more about BIF than I ever will, but would using the auto-select AF grid instead of a single AF point work better (or maybe you're already doing that)?
 

tomO2013

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This I had never heard of.
Thanks for the tip. I don't have my camera here beside me , but does it make a significant difference?? Also do you know why it makes such a difference? I would have thought such a setting was specific to the EVF and not the AF mechanism. But if it works I'm happy to give it a shot :)

* Use smaller focus points
* Set EVF to sample rate to high. (it also improves AF)
 

pellicle

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Hi

...say that the hunting is usually with small or distant objects. A distant bird on a blue sky for instance, the 100-300mm has a tough time focusing on it, it shoots back and forth, back and forth instead
Ahh, I see the problem, you have been attempting to use Auto Focus (known as AF). In this situation you need to use Magic Focus (or MF).

MF engages a much more powerful processing unit, which is connected to the camera using a massive array of optical sensors and takes control of the lens using a system of (almost nano technology) myofibrils and nerves. All under control of a massively parallel neural net (which like all neural nets of course requires training). Best yet, this system is entirely silent is has its own independent power supply.

Once upon a time all cameras came equipped with this system.

I began training my Photographer MF system with pre-focusing on something which was at about the same distance as I knew the bird was and then in conjunction with an aperture of say f5.6 would usually be pretty bang on.

Standardising on MF lenses which rotate in consistent manners for focus distant <> focus closer greatly improves the MF Ai neural net system to train, and in almost no time you will begin to see that this system does full time focus tuning and follow focus. My MF system has been quite consistent in results under situations which would fool all AF systems

Subscribe to see EXIF info for this image (if available)


even under difficult low light conditions
Subscribe to see EXIF info for this image (if available)


Give it a go ... you never know, you may like MF and find that it has a place in your repertoire

:-D
 

barry13

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Hi,

MF engages a much more powerful processing unit, which is connected to the camera using a massive array of optical sensors and takes control of the lens using a system of (almost nano technology) myofibrils and nerves. All under control of a massively parallel neural net (which like all neural nets of course requires training). Best yet, this system is entirely silent is has its own independent power supply.
"The single most important component of a camera is the twelve inches behind it." – Ansel Adams
:tongue:

Standardising on MF lenses which rotate in consistent manners for focus distant <> focus closer greatly improves the MF Ai neural net
Are there some lenses which should be avoided because they don't have consistent focus methods?

I'm planning to get the Oly 12-40mm 2.8 and the 17mm 1.8... right now have 2 kit lenses (14-42 II, 40-150 R), and several ZD 4/3 lenses.

Considering the following for later:
Pana 35-100mm F2.8
OR
Oly 75-300mm F4.8-6.7 II

7-14mm F2.8 m43 Pro

Maybe a good fisheye (If I sell my 4/3 ZD 8mm)

25mm F1.8 Oly
60mm F2.8 1:1 Macro
45mm F1.8 Oly
75mm F1.8 Oly
85mm F1.4 Samyang

40-150mm F2.8 Pro
OR
50-200mm F/2.8-3.5 std or SWD ZD 4/3


Thanks
Barry
 

pellicle

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Hi

"The single most important component of a camera is the twelve inches behind it." – Ansel Adams
:tongue:
great quote :-D


Are there some lenses which should be avoided because they don't have consistent focus methods?
well avoided seems strong, but its just that different brands focus in different directions. If you mix n match brands it can do your head in.

For instance my FD series operate both focus and aperture in different directions to my OM lenses. I had intended to standardise on OM lenses as they work on my EOS system (and the FD do not), but my FD300mm f4 is just so much nicer to use than my OM 300 is I sold it and now try not to use the OM stuff on the micro4/3 and only use my OM lenses on EOS.
 

EarthQuake

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Give it a go ... you never know, you may like MF and find that it has a place in your repertoire

:-D
Yes, I am aware of the concept of MF, and use it from time to time, often when AF fails. However, it doesn't help me with the issue at hand, what I would like to know is if the 75-300mm has any advantage with focus speed/accuracy/hunting over the 100-300, using the same technique, in the same conditions, etc.
 

pellicle

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Hi

what I would like to know is if the 75-300mm has any advantage with focus speed/accuracy/hunting over the 100-300, using the same technique, in the same conditions, etc.

I assumed you were aware of MF but I guess my tongue in cheek point calling it Magic Focus was that you were pehaps expecting too much of it. With so little data to clutch onto, any AF system is going to be totally stumped as to what its looking for and where. I don't think your problem is "hunting" but the inability of any system (phase or contrast based) to actually know what you're seeing and what you want it to focus on.

I agree with the ideas of making the AF point smaller (as small as possible) and then picking a single AF point. I would expect that since Pany seem to have a better mechanism for sensing AF than Oly that the 100-300 may have the edge (but I've never used either).
 

dejongj

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Why would you expect Panasonic to have a better AF mechanism than Oly? Man, the Oly is lightning quick in getting autofocus without hunting....And dare I say rather consistent in that approach with all their lenses opposed to the Panasonic equivalents where you have to pick out the gems....Very odd...

Several reviews have remarked on the hunting of the 100-300.....Some of my old Nikon format lenses were like that as well.....
 

EarthQuake

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Hi




I assumed you were aware of MF but I guess my tongue in cheek point calling it Magic Focus was that you were pehaps expecting too much of it. With so little data to clutch onto, any AF system is going to be totally stumped as to what its looking for and where. I don't think your problem is "hunting" but the inability of any system (phase or contrast based) to actually know what you're seeing and what you want it to focus on.

I agree with the ideas of making the AF point smaller (as small as possible) and then picking a single AF point. I would expect that since Pany seem to have a better mechanism for sensing AF than Oly that the 100-300 may have the edge (but I've never used either).
Well, lets take two lenses I have used as an example, the Pana 20/1.7 and the Oly 17/1.8. In the same shooting situations, (eg, low light) the Oly hunts way, way less and is much faster to get a lock, while the 20/1.7 will often fails to get a lock at all. So again, what I'm wondering is if there is a similar issue with the 100-300 vs the 75-300. I think the easy assumption to make is the 100-300mm is half a stop faster, so it should hunt less, but the 20/1.7 is faster than the 17/1.8 as well.

For what its worth, the small-AF point does help with the 100-300, and the EM1 is significantly better than the EM5 with that lens before the small AF point update on the EM5 (EM5 is better now but still not as good as the EM1).

I get the MF joke, its cute and all, but a bit like asking someone which car is faster, A or B, and they tell you "Well I don't drive but my feet get the best gas mileage". Sorry if my response seemed rude, I don't tend to have a good sense of humor in the morning.

Why would you expect Panasonic to have a better AF mechanism than Oly? Man, the Oly is lightning quick in getting autofocus without hunting....And dare I say rather consistent in that approach with all their lenses opposed to the Panasonic equivalents where you have to pick out the gems....Very odd...

Several reviews have remarked on the hunting of the 100-300.....Some of my old Nikon format lenses were like that as well.....
Thanks for the input, that sounds promising for the 75-300mm. Maybe I will just have to pick one of and see for myself. I am going on a trip to Japan this fall and the lighter weight would be a big advantage to me, I just don't want to lose any AF speed with the slower aperture of the 75-300.
 

pellicle

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Hi

Sorry if my response seemed rude, I don't tend to have a good sense of humor in the morning.
not at all. ASCII frequently fails to convey nuance.

Wrt the lenses you mentioned, I never found any hunting on Panasonic bodies with Panasonic lenses. I expect its possible. My EOS 300mm only ever hunted when it was given a task that was impossible for it. So I regard 'hunting' as a signal to the user that they don't get the way the AF system works. I developed an attitude that AF was like an assistant. It pulled focus but wasn't real smart. So if I pointed the focus point at a white wall or blue sky it would (expectably) fail.
I had to make its job easier by giving it something with strong vertical (and later horizontal) lines.

The exact nature of CDAF is different to Phase Detect but the underlying ideas are similar.

When the focus point is jumping all around the screen (as when using a telephoto and a bird) I consider it a miracle if it got anything as it wouldn't know which pixels to give weight to at any given time.

Hth
 

pellicle

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Hi
Why would you expect Panasonic to have a better AF mechanism than Oly?.
try reading this recent thread for instance:
https://www.mu-43.com/showthread.php?t=64316

and look for DFD

also
http://www.imaging-resource.com/PRODS/panasonic-gh4/panasonic-gh4A.HTM#DFD

I am not sure when Panasonic actually started putting it on cameras (although I know when they announced it). It would make sence for them to have some things in development in the field without letting people know about it till they were clear it worked. For my vision my GH1 snaps focus much faster with my 14-45 than the same vintage Oly cameras did. I also noticed that compared to my friends E-M5 last weekend my GH1 focused the 14-45 lens faster than his focused it.

I admit don't know and I'm just conjecturing. Have you done side by side tests similarly?

Personally I take many reviews with a grain of salt. For instance I read dpreview mainly because they standardise many things in their reviews. Their opinions are often barefaced marketing.
 
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