DOF On Four Thirds

[retrovox]

Was following the 2 threads in dpreview forum:

http://forums.dpreview.com/forums/re...hread=26073496

http://forums.dpreview.com/forums/re...hread=26180515

Interesting views and discussions in there. One of the observations made was that, for 4/3 to do very shallow DOF, it's possible. But very expensive. 150mm f2.0, 35-100 f2.0 etc. So far, there isn't any Zuiko digital lens that is brighter than f2.0. And judging from the prices of the above 2 lenses, I think any brighter lenses won't come cheap. In my opinion, I think Olympus should make more brighter, affordable lenses to compensate for the additional DOF (due to smaller sensor) as well as to entice more photographers into 4/3 system.

I'm also a 4/3 user. I do like shooting portraitures, but at times, I really hope there is a mid-telephoto lens that can allow me to do a half body or even a full body shot with shallow DOF, without breaking my bank.

[microcosm]

Originally Posted by retrovox Was following the 2 threads in dpreview forum: http://forums.dpreview.com/forums/re...hread=26073496 http://forums.dpreview.com/forums/re...hread=26180515 Interesting views and discussions in there. One of the observations made was that, for 4/3 to do very shallow DOF, it's possible. But very expensive. 150mm f2.0, 35-100 f2.0 etc. So far, there isn't any Zuiko digital lens that is brighter than f2.0. And judging from the prices of the above 2 lenses, I think any brighter lenses won't come cheap. In my opinion, I think Olympus should make more brighter, affordable lenses to compensate for the additional DOF (due to smaller sensor) as well as to entice more photographers into 4/3 system. I'm also a 4/3 user. I do like shooting portraitures, but at times, I really hope there is a mid-telephoto lens that can allow me to do a half body or even a full body shot with shallow DOF, without breaking my bank.

If you want out of the shelf solution, they will not come cheap, like those 85mm f1.4 lenses. But with some creativity using EX25, you can obtain almost unusable DOF... so shallow that it is a joke. And also, these days, you have photoshop to create more bokeh...

Ok, some of you guys are purists, so well...

But honestly, there is a limit to that crazy pursue of shallow DOF. It is more about knowing how each lens perform... just like ZD lens users claiming things that the other camera system cannot achieve. It will be a never ending story... sigh...

[halcy0n]

*looks at bank* Broken already....

truth is, its a fetish for bigger, faster lenses. One thing that did puzzle me is how the 35-100 is the only lens that breaks the panacea of four-thirds being smaller and lighter lenses. It is one stop faster than the usual 70-200/2.8 but it is also bigger and heavier, DOF may be comparable to 2.8, sharpness may be comparable.

Maybe Sigma will make more fast primes or a 35-100/2.8 that is lighter, smaller and sub $2,000.

[drakon09]

Sharpness comparable?...

I don't know about that - it's actually too bleedin' sharp for portraits! Ask marky...

[microcosm]

Originally Posted by halcy0n *looks at bank* Broken already.... truth is, its a fetish for bigger, faster lenses. One thing that did puzzle me is how the 35-100 is the only lens that breaks the panacea of four-thirds being smaller and lighter lenses. It is one stop faster than the usual 70-200/2.8 but it is also bigger and heavier, DOF may be comparable to 2.8, sharpness may be comparable. Maybe Sigma will make more fast primes or a 35-100/2.8 that is lighter, smaller and sub $2,000.

1. There is the 90-250, which is truly a monster.

2. Even if Sigma makes a 35-100 f2.0/2.8, the elements quality of Sigma will defeat the purpose of someone needing and wanting the ZD 35-100 f2.0. The MTF, colour richness, speed is the reason why I invested in the SHG lenses. Buying a Sigma (sorry Sigma fans) is always a compromise. In the end, you will end up buying a SHG. Why not take your time to save the money and shoot freelance jobs and let the gear pay for itself and buy the SHG lens eventually? This is a wiser way to go for gear investment.

*MTF shows that the Sigma is "half the lens" of a ZD SHG... and the yellow cast on the Sigma drives me bananas... some of you might even remember I using the 30mm f1.4 as a peperweight at one time... I hardly use that lens at all, and when I eventually donate/sell it off, it still look brand new... yes, f1.4 can be useful at times, but now with IS, things are a lot better. In such extremely low lighting condition, I rather go the other way of thought and think of creative use of flash instead.

Just something that I want to share so that you guys don't burn your hard earned money on things that you really do not need, and when there is a piece of gear that you are lusting after, it is wiser that you save slowly and taking the time to finally then decide if you really need it when you have the money in your pocket at the camera store.

Else, you will be wasting your money.

Don't get bitten by the BBB bug... it is very painful...

[VSonic06]

Originally Posted by halcy0n One thing that did puzzle me is how the 35-100 is the only lens that breaks the panacea of four-thirds being smaller and lighter lenses. It is one stop faster than the usual 70-200/2.8 but it is also bigger and heavier, DOF may be comparable to 2.8, sharpness may be comparable. =

35-100/2 isn't the only monster lens compared to other DSLR systems. The ZD 8mm/3.5 is also chunkier and pricier than the competition yet does not deliver significantly better image quality.

[microcosm]

Originally Posted by VSonic06 35-100/2 isn't the only monster lens compared to other DSLR systems. The ZD 8mm/3.5 is also chunkier and pricier than the competition yet does not deliver significantly better image quality.

Yes and no. The 8mm has a very usable "centre" which yields very nice images as compared to some of the competition. Depends on the photographer, really... I have shot a lot of stuff on the 8mm and so have "marky" as well as you can see in his gallery. I would still consider the 8mm a "value for money" lens and the build quality is really good. I do have to comment on the purple fringing on the 8mm fisheye though, but that is something that can be easily fixed in post. So that does not really bother me much.

[olymac]

Originally Posted by retrovox ....... In my opinion, I think Olympus should make more brighter, affordable lenses to compensate for the additional DOF (due to smaller sensor) as well as to entice more photographers into 4/3 system. I'm also a 4/3 user. I do like shooting portraitures, but at times, I really hope there is a mid-telephoto lens that can allow me to do a half body or even a full body shot with shallow DOF, without breaking my bank.

You mean something like this ......?

http://www.cameraquest.com/top30028.htm

[halcy0n]

Originally Posted by olymac You mean something like this ......? http://www.cameraquest.com/top30028.htm

That lens is too expensive, because after I buy it, I need to buy a pickup to move it around.

[Kirika]

hmm...they may seem numerically similar (with a goodly 600++ bucks price difference), but one is a prime and one is a zoom. Perhaps there is a reason for this design choice?

[VSonic06]

I've used both the Pentax 10-17 and ZD 8mm extensively (the ZD 8mm came first), both are just as sharp, both have good flare control and both suffer the same amount of PF. But I do find the Pentax has better contrast and color thanks to the SMC coating.

Its not so much about 'value for money' or 'usable centre' when it comes to fisheye on FourThids as the ZD8mm is pretty much the only option available unless one is willing to put up with Pelengs or use adaptors.

[microcosm]

Originally Posted by VSonic06 I've used both the Pentax 10-17 and ZD 8mm extensively (the ZD 8mm came first), both are just as sharp, both have good flare control and both suffer the same amount of PF. But I do find the Pentax has better contrast and color thanks to the SMC coating. Its not so much about 'value for money' or 'usable centre' when it comes to fisheye on FourThids as the ZD8mm is pretty much the only option available unless one is willing to put up with Pelengs or use adaptors.

There is always the option of using adapters and other brands of FE lenses... you really cannot go wrong with focusing with a FE lens...

[VSonic06]

Originally Posted by Kirika hmm...they may seem numerically similar (with a goodly 600++ bucks price difference), but one is a prime and one is a zoom. Perhaps there is a reason for this design choice?

I presume you're refer to the ZD 8mm v Pentax 10-17mm fisheye lenses? The zoom on the Pentax/Tokina fisheye does help in certain situations, eg. to 'crop out' your shadow or unwanted parts of the image. Otherwise you'll have to 'zoom' with your feet. Of course when zoomed in the fisheye novelty is somewhat lost.

[OlyFlyer]

Originally Posted by retrovox I'm also a 4/3 user. I do like shooting portraitures, but at times, I really hope there is a mid-telephoto lens that can allow me to do a half body or even a full body shot with shallow DOF, without breaking my bank.

DOF is a function of aperture and distance. An aperture of f2 can give you paper thin DOF if used right.

This image is taken yesterday, just doing some DOF experiments.



A 100% crop of the marbels clearly shows that focus was on the center marbel.



The image is taken with the ED50/f2 lens at f2. I think that lens is really nice for portraits.

[marky]

Originally Posted by drakon09 Sharpness comparable?... I don't know about that - it's actually too bleedin' sharp for portraits! Ask marky...

Yes.. there is such things as lens too freaking sharp.. 35-100 at F2 and also the 8mm at F3.5.. both are sharp and FE is really useable.. you can see the pores on the nose at 100% zoom..

Time to de-sharp my E3.. haha...

[retrovox]

Originally Posted by OlyFlyer DOF is a function of aperture and distance. An aperture of f2 can give you paper thin DOF if used right. This image is taken yesterday, just doing some DOF experiments. A 100% crop of the marbels clearly shows that focus was on the center marbel. The image is taken with the ED50/f2 lens at f2. I think that lens is really nice for portraits.

4/3 can do very shallow DOF on small objects. No doubt about it. But when it comes to half body and full body portraits, it's going to be very expensive. Also, the lens will be very bulky.

[schon]

Originally Posted by retrovox 4/3 can do very shallow DOF on small objects. No doubt about it. But when it comes to half body and full body portraits, it's going to be very expensive. Also, the lens will be very bulky.

it's no secret that the 4/3s system offers 2x the dof as compared to a FF camera. but...

from wrotniak.net



bulky?

[halcy0n]

Originally Posted by retrovox 4/3 can do very shallow DOF on small objects. No doubt about it. But when it comes to half body and full body portraits, it's going to be very expensive. Also, the lens will be very bulky.

Sorry, but i honestly don't see how DOF is related to the size of the object.... As far as I understand, DOF is dependent on focal length, aperture and the distance between objects and the camera. From a technical perspective, we all recognise that the 2x factor in a 4/3 system gives twice the amount of DOF for the same aperture size. To the extent that the differences in DOF were to be addressed by building faster lenses, they would probably be bigger and more expensive.

However, I think what Olyflyer and Schon are trying to demonstrate are means to manage the greater DOF created by the smaller image size in a 4/3 system by composition / placement of the objects. In Olyflyer's case, bringing the foreground closer to the lens and in Schon's case, placing background further away from the lens.

[Clockunder]

Originally Posted by halcy0n Sorry, but i honestly don't see how DOF is related to the size of the object.... As far as I understand, DOF is dependent on focal length, aperture and the distance between objects and the camera. From a technical perspective, we all recognise that the 2x factor in a 4/3 system gives twice the amount of DOF for the same aperture size. To the extent that the differences in DOF were to be addressed by building faster lenses, they would probably be bigger and more expensive. However, I think what Olyflyer and Schon are trying to demonstrate are means to manage the greater DOF created by the smaller image size in a 4/3 system by composition / placement of the objects. In Olyflyer's case, bringing the foreground closer to the lens and in Schon's case, placing background further away from the lens.

If the object is just a few cm in size and you're using 50mm lens, you can still stand just 10+cm away to shoot with your 4/3 camera to have it within your field of view and have very shallow DOF because the shooting distance is very near.

But if the subject is a half body which is about 1m tall and you're also using 50mm lens, you would need to stand about 2.5m way to accomodate it.

Clearly, the much further distance (250cm vs 10+cm) would mean a much deeper DOF.

If you don't want to stand further whe the object is much bigger, then you would need a shorter focal length to accomodate it in your picture. This also means a deeper DOF.

Although the effect applies to all sensor sizes, the narrower the field of view for the camera system (i.e. smaller image senosr), the more pronounce the deepening of DOF. That is also why even compact point and shoot cameras can achieve very shallow DOF when shooting close-up on small object with F/2.8 but cannot achieve it when there is a need to shoot much further away for bigger objects.

[halcy0n]

Originally Posted by Clockunder If the object is just a few cm in size and you're using 50mm lens, you can still stand just 10+cm away to shoot with your 4/3 camera to have it within your field of view and have very shallow DOF because the shooting distance is very near. But if the subject is a half body which is about 1m tall and you're also using 50mm lens, you would need to stand about 2.5m way to accomodate it. Clearly, the much further distance (250cm vs 10+cm) would mean a much deeper DOF. If you don't want to stand further whe the object is much bigger, then you would need a shorter focal length to accomodate it in your picture. This also means a deeper DOF. Although the effect applies to all sensor sizes, the narrower the field of view for the camera system (i.e. smaller image senosr), the more pronounce the deepening of DOF. That is also why even compact point and shoot cameras can achieve very shallow DOF when shooting close-up on small object with F/2.8 but cannot achieve it when there is a need to shoot much further away for bigger objects.

Yes, I am aware of this, but again, the variation is really in the object distance.