Buying a Standard Lens

[andrewsugi]

@GrumpyDiver,

I can't thank you enough for your reviews. Maybe this is what I really need. I have no one to review my photos. Thank you again (especially for editing my post).

I have read most of the tutorials here in CiC, but maybe I take it too lightly. So, I may have to go back and read it all over again and redo my training. I hope I can be better photographer after this.

[rpcrowe]

Quite often, problems with the various kit lenses (from a wide variety of manufacturers) can be removed, or at least lessened, in post processing.

CA is usually quite easy to remove and ALL DIGITAL IMAGES usually need some amount of post processing.

I don't use any in-camera sharpening or sharpening when I open my RAW images. Instead, the very first step in my workflow is to apply the NIK Software Sharpener Pro Raw Presharpener filter I will then occasionally do some output sharpening. But, most often, the RAW PRESHARPENER is all that I need in the way of sharpening.

However, if your camera/lens is under warranty, sending it back to a service center might be the best way to ensure that the camera/lens work together in the best fashion...

[andrewsugi]

Sure. Your 14-42mm F3.5-5.6 lens will have a maximum aperture of about f/4.8 at 25mm:

I am lost. Why my lens maximum aperture is f/4.8? Not f/3.5?

[Dave Humphries]

I have one more question though. Most of the people commenting in my thread suggested me not to change my lens. Then, when is the right time for me to buy new lenses?

When you need a focal length, aperture or some other feature, that your current lens(es) cannot achieve.

e.g.
A telephoto to capture say, birds at some distance
Or an Ultra Wide Angle lens (say approx. 7-8 mm in your format)
Or a 'faster' lens - one with a wider maximum aperture (for narrower DoF)
Or a macro lens, so you can shoot small subjects from very close

In general; only after 2-3 years shooting would I expect someone to know enough to replace a lens on quality issues and make a choice to be pleased with the result.

We'll be happy to help you improve by reviewing your images.

All the best, Dave

[pnodrog]

Are you saving as jpegs? If so what size, quality and Processing Options (PictureMode P68 of manual). If RAW what RAW conversion software are you using and what is you sharpening method?

[xpatUSA]

I am lost. Why my lens maximum aperture is f/4.8? Not f/3.5?

Dem didn't say that. He estimated the effective aperture for a focal length of 25mm, not 14mm. [oops deleted]

Lenses that keep a constant aperture throughout the zoom range are not common, especially with kit lenses. It has to with how the lens elements move relative to the actual aperture hole while zooming.

Plus, lenses with constant aperture can be pretty big! For example my Sigma 17-50mm, a constant f/2.8 lens, is 77mm diameter at the front - but it's only an APS-C size lens.

[dem]

Sure. Your 14-42mm F3.5-5.6 lens will have a maximum aperture of about f/4.8 at 25mm

I am lost. Why my lens maximum aperture is f/4.8? Not f/3.5?

The maximum aperture of your lens changes as you zoom in:

f/3.5 at 14 mm
f/4.8 at 25 mm
f/5.6 at 42 mm

You can probably see it changing in the A priority mode if you start with f/3.5 at 14 mm and slowly zoom in. Keep an eye on the f-number shown on the LCD - it is going to go up to f/5.6 by the time the lens is at 42 mm.

This is why your lens is marked "14-42 mm F3.5-5.6", not "14-42 mm F3.5".

[Black Pearl]

@Dave Humpries, thanks for the advice. I may have to learn more about photograhpy so I can produce better pictures.

I have one more question though. Most of the people commenting in my thread suggested me not to change my lens. Then, when is the right time for me to buy new lenses?

Not sure there is such a thing as the 'right time' to buy another piece of equipment. However you can buy something new whenever you like so long as you understand that doing so shouldn't be to 'fix' an issue but to add possibilities to your shooting capabilities that you currently don't have - or just on a whim because you fancy something new.

[Manfred M]

@GrumpyDiver,

I can't thank you enough for your reviews. Maybe this is what I really need. I have no one to review my photos. Thank you again (especially for editing my post).

I have read most of the tutorials here in CiC, but maybe I take it too lightly. So, I may have to go back and read it all over again and redo my training. I hope I can be better photographer after this.

This is a site for learning about photography and our membership runs from beginners through to very experienced photographers. The Nature and Architecture and People and Pets forums are there for people to post their work for critique and suggestions. I would suggest you might like to take advantage of this.

I think the members would agree when I say that some of the people who joined as beginners have become very good photographers and if you went back to some of their earlier posts and look at the work they are posting now, you would be pleasantly surprised.

A bit of a warning though, it takes a good understanding of both the creative sides and technical sides of photography to become a good photographer and that takes lots of practice. One of my favourite photographic quotes comes from the famous French photojournalist who said "your first 10 000 images are your worst". Given my own personal experience, I would have to say he was right.

[inkista]

... The mFT system embeds lens correction data (mostly distortion, vignetting and CA) in the raw data and that is picked up by the raw converter and applied to the image. My experience is with Panasonic mFT cameras, but based on what I've read, Olympus works exactly the same way....

Small footnote. Olympus actually doesn't embed all the same correction information that Panasonic does (some of the Leica lenses don't either). Panasonic lenses embed both distortion and C/A correction factors, but Olympus lenses only embed factors for distortion correction.

Andrew, there's a stackexchange answer I posted a while back on some basic technique issues that a lot of newbs run up against and blame the camera for. While that question was asked/answered for a Canon shooter, the same principles do apply in the case of MFT.

As for which lens to go for, if you want a fast normal prime in MFT, I'd actually say look at the Olympus m.Zuiko 25mm f/1.8. It came out after the Panasonic Lumix 20/1.7 I own, otherwise I might have gone for it. It's more expensive than the Lumix 25/1.7, so if your budget doesn't allow or you want a pancake lens, then don't bother. But given that my favorite lens on mft is the m.Zuiko 45/1.8, and the 25/1.8 looks similar, optically, that would be my pick today. The main tradeoff over the Pana (aside from price) seems to be sharpness for vignetting (i.e., the Oly's sharper, but vignettes more wide open).

Just keep in mind, no lens is perfect. It's still made of glass, not magic air, and no lens has an MFT chart that's a straight line across the top. Fast primes are good, sharp, fast little suckers at low cost, but they don't zoom, and nearly all of them exhibit LoCA (aka purple fringe) if used wide open in bright light.

However, as everyone else is counseling you, I'm not sure you know whether or not you really want a fast normal prime, yet. Practice a bit more until you know what it is you need. Concentrate on whether you need a faster lens (more maximum aperture), a wider lens, a longer lens. Also, you can use Panasonic lenses, as long as they're for micro four-thirds. Just like Olympus, Panasonic also made "four thirds" dSLR lenses (i.e., you want a lens that's designated as m.Zuiko, Lumix G, or Leica DG, otherwise it won't mount directly onto your camera).

[andrewsugi]

Are you saving as jpegs? If so what size, quality and Processing Options (PictureMode P68 of manual). If RAW what RAW conversion software are you using and what is you sharpening method?

I mostly saved my photos as Large Fine jpegs. I rarely used RAW because I haven't learned any post-processing technique yet.


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[andrewsugi]

Not sure there is such a thing as the 'right time' to buy another piece of equipment. However you can buy something new whenever you like so long as you understand that doing so shouldn't be to 'fix' an issue but to add possibilities to your shooting capabilities that you currently don't have - or just on a whim because you fancy something new.

So you are saying that no such thing as bad lens? Buying new lens is not necessary if you don't need new possibilities?


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[andrewsugi]

This is a site for learning about photography and our membership runs from beginners through to very experienced photographers. The Nature and Architecture and People and Pets forums are there for people to post their work for critique and suggestions. I would suggest you might like to take advantage of this.

I think the members would agree when I say that some of the people who joined as beginners have become very good photographers and if you went back to some of their earlier posts and look at the work they are posting now, you would be pleasantly surprised.

A bit of a warning though, it takes a good understanding of both the creative sides and technical sides of photography to become a good photographer and that takes lots of practice. One of my favourite photographic quotes comes from the famous French photojournalist who said "your first 10 000 images are your worst". Given my own personal experience, I would have to say he was right.

Thank you, Dave. I will look to the forum section.

I have also seen that quote at DRTV channel in YouTube and I have to say that I agree with it. I believe that every single expertise should have their own number of failures before a person can master it. Nice quote, Dave.


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[Manfred M]

So you are saying that no such thing as bad lens? Buying new lens is not necessary if you don't need new possibilities?

Andrew - there is nothing wrong with buying new equipment, so long as it does something meaningful for your photographic needs. I own a number of lenses, but each one was bought for a specific purpose to fulfill a specific photographic need. In general, buying a lens that covers a focal length that you already have covered might not be a wise investment, or on the other hand it could be, if that lens does something quite specific for you (for instance, low light photography, so a fixed focal length lens with a higher maximum aperture might be worth considering).

I suspect Robin's comments to you were similar to my thoughts - buying a new lens to fix a perceived problem might not be the best use of money. Based on the images you posted, I suspect that was likely the right advice for you as the issues in your images were not lens related, but rather due to the way your camera was set up and the way you are shooting.

[rpcrowe]

Andrew...

The f/stop is the relationship between the diameter of the aperture (opening) of your lens and the focal length of that lens. The diameter of the aperture over the focal length. With a zoom lens, as you increase the focal length by zooming the size of the aperture must increase in order for the f/stop to remain the same.

However, with all kit lenses and many other zoom lenses, the size of the aperture remains the same as the focal length is increased, therefore the relationship between the aperture and the focal length changes.

Constant f/stop lenses are most often larger in diameter and usually more expensive than variable f/stop lenses. However, the price of the lens is not always an indicator. My 100-400mm f/4.5-5.6L lens is very expensive (around $2,000 U.S. Dollars here in the USA) but, is a variable aperture lens with an aperture of f/4.5 at 100mm which is reduced to f/5.6 when it reaches 400mm. I can only imagine how much the lens would weigh and cost if it were a lens with a constant aperture

[andrewsugi]

Small footnote. Olympus actually doesn't embed all the same correction information that Panasonic does (some of the Leica lenses don't either). Panasonic lenses embed both distortion and C/A correction factors, but Olympus lenses only embed factors for distortion correction.

Andrew, there's a stackexchange answer I posted a while back on some basic technique issues that a lot of newbs run up against and blame the camera for. While that question was asked/answered for a Canon shooter, the same principles do apply in the case of MFT.

As for which lens to go for, if you want a fast normal prime in MFT, I'd actually say look at the Olympus m.Zuiko 25mm f/1.8. It came out after the Panasonic Lumix 20/1.7 I own, otherwise I might have gone for it. It's more expensive than the Lumix 25/1.7, so if your budget doesn't allow or you want a pancake lens, then don't bother. But given that my favorite lens on mft is the m.Zuiko 45/1.8, and the 25/1.8 looks similar, optically, that would be my pick today. The main tradeoff over the Pana (aside from price) seems to be sharpness for vignetting (i.e., the Oly's sharper, but vignettes more wide open).

Just keep in mind, no lens is perfect. It's still made of glass, not magic air, and no lens has an MFT chart that's a straight line across the top. Fast primes are good, sharp, fast little suckers at low cost, but they don't zoom, and nearly all of them exhibit LoCA (aka purple fringe) if used wide open in bright light.

However, as everyone else is counseling you, I'm not sure you know whether or not you really want a fast normal prime, yet. Practice a bit more until you know what it is you need. Concentrate on whether you need a faster lens (more maximum aperture), a wider lens, a longer lens. Also, you can use Panasonic lenses, as long as they're for micro four-thirds. Just like Olympus, Panasonic also made "four thirds" dSLR lenses (i.e., you want a lens that's designated as m.Zuiko, Lumix G, or Leica DG, otherwise it won't mount directly onto your camera).

What a great artikel in stackexchange, Inkista. After reading your article, I felt encouraged to improve my skills. I have to admit that my skills are to be blamed for my unsharply-looked images.

I have some questions though. What is the complete formula for Reciprocal Rule? You mentioned it in your stockexchange answer (though you mentioned it as 1/focal length guide to get sharp image). I have read about it a couple times and every time I read it, the formula was added, for example, if your camera have image stabilization, then the formula become "2^n/focal length" where 'n' is the number of image stabilization axis.

The other question is if the largest aperture of a camera is that weak, when is the best time to use it? Is it only on a very low light condition so the camera can get more light?


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[Manfred M]

I have some questions though. What is the complete formula for Reciprocal Rule? You mentioned it in your stockexchange answer (though you mentioned it as 1/focal length guide to get sharp image). I have read about it a couple times and every time I read it, the formula was added, for example, if your camera have image stabilization, then the formula become "2^n/focal length" where 'n' is the number of image stabilization axis.

Carefully said, that is an old rule of thumb used with 35mm film cameras (i.e. the same as a full frame camera) and the assumption worked reasonably well for reasonably sized enlargements (say A4 / 8" x 10" prints) held at a normal viewing distance (about arms length). With crop frame sensors one needs to compensate for the "magnification factor"; i.e. a 25mm focal length setting is going to perform about the same as a 50mm lens on a full frame camera.

Image stabilization is also quite variable as different lenses (with in lens stabilization) or camera bodies (with in body stabilization) are going to perform differently. One of my older lenses gives me perhaps 1 - 2 additional stops while some of my newer ones are probably 3 or 4 stops.

All that being said, as with any rule of thumb, depending how you shoot (good practices in bracing the camera) I could easily beat the old 1/focal length rule by about the same factor as stabilization provides - shooting a 50mm lens at 1/15th second is something I do fairly regularly (and the 50 is not stabilized).

The other question is if the largest aperture of a camera is that weak, when is the best time to use it? Is it only on a very low light condition so the camera can get more light?

That is really more of a lab number than something I worry about in my day to day shooting, and in fact the reason I have fast lenses (f/2.8 and faster) is to shoot them wide open to get very shallow depth of field. People don't buy fast, expensive lenses to solely shoot them at f/8 or f/11.

Unless you are shooting off a very heavy duty tripod or shoot at shutter speeds of over 1/1000th sec, camera shake is going to have more of an impact on sharpness than the theoretical limits from MTF charts. You will see the same stories all over the internet about not shooting at apertures smaller than f/11 and here too, the writers are correct, that the lenses are diffraction limited, but unless you are shooting under ideal lab conditions, chances are you'll never notice. Yes, f/22 will give you a bit of softness (about the same as shooting a lens wide open), but if you need that depth of field to get the image to work, use that aperture!

[LePetomane]

This has been a very good and informative thread. Another testament to the eagerness of the members of this forum to share information.

[inkista]

What is the complete formula for Reciprocal Rule? You mentioned it in your stockexchange answer (though you mentioned it as 1/focal length guide to get sharp image). I have read about it a couple times and every time I read it, the formula was added, for example, if your camera have image stabilization, then the formula become "2^n/focal length" where 'n' is the number of image stabilization axis.

Manfred mostly answered this, but the key thing to keep in mind is that this is a "rule of thumb"--general guidance, not a precise hard rule that always works every time. Remember that your shutter speed is going to rely on both camera shake and subject motion. The 1/focal_length (or 1/focal_length*crop_factor) rule is just a way for you to ballpark the number and do a rough guesstimate. If you have stabilization, that can reduce the speed by the number of stops your camera stabilizes. But then, bad handholding technique, a very high resolution sensor, or a very small unstable camera can still require an increase in the shutter speed.

Your best guide is going to be experience. Use these numbers as guides, but then see what you get and adjust accordingly. It's usually more of a range, not a hard-and-fast specific speed you have to get. And practice can improve your skill level. It's like learning to sharp shoot. You learn to control how your body moves the camera, not just by holding, but also by breathing.

The other question is if the largest aperture of a camera is that weak, when is the best time to use it? Is it only on a very low light condition so the camera can get more light?

It's when the tradeoffs of using it at that setting are worth it to you. If you want that super-thin depth of field enough to trade off sharpness then go for it. If you need that faster shutter speed and you've already maxed out ISO settings you're comfortable with. If you just can't get by with f/2.8. Etc. But you always want to be aware that you're trading in a little sharpness, possible purple fringing, and vignetting, and making accurate autofocusing harder for yourself.

You can also always post-process to sharpen, and to remove or reduce vignetting and purple fringing. But are you willing to spend the time to shoot RAW and do so?

[dem]

I have some questions though. What is the complete formula for Reciprocal Rule? I have read about it a couple times and every time I read it, the formula was added, for example, if your camera have image stabilization, then the formula become "2^n/focal length" where 'n' is the number of image stabilization axis.

For the mathematically minded amongst us, here is my ultimate formula for choosing the shutter speed when shooting hand-held:

SS = 2^n / (ff_equivalent_focal_length * C),

where

ff_equivalent_focal_length = actual_focal_length * crop_factor is the "full frame" or "35 mm" FL equivalent. Anyone who shot both ff DSLRs and bridge cameras with a crop factor of 5.6 will confirm that it is the angle of view (as traditionally defined via the "equivalent" focal length) what matters here.

n is the number of stops that the image stabilisation (IS, OIS, VR, sensor shift etc...) is providing. Use n=0 when there is no IS, 2^0 = 1. While n is not the number of stabilisation axis per say and it can be, for example, n=2.5 or n=4.7, many modern cameras have IS with 5 axis that give abut 5 stops of image stabilisation. With such cameras/lenses you can get sharp images with SS about 32 times slower when you turn the IS on.

C is the adjustable parameter that depends on everything that has not been mentioned above - mainly your requirements for sharpness, your physical abilities and shooting technique:

C = 0.7 if the final image is going to be printed 4"x6" or downsampled to 2 Mpx to share on the web
C = 1 if you print 8"x12" and do not mind a little bit of softness that is hardly noticable
C = 2 if you print 8"x12" from a 16 Mpx camera and want it nice and sharp
C = 3 if you use a 36 Mpx camera and want it pixel sharp at 100% magnification on the computer screen

Double the value of C if you are tired, angry, excited, had a coffee or find the camera uncomfortable to hold.

Halve the value of C if you are a policeman, a member of a local shooting club or are leaning against a brick wall while shooting.

Now, if you took everything into account correctly, take about 10 shots of the same subject. Check the images: 3 to 7 of them should be OK. If none of them is sharp enough, double the shutter speed. Repeat if necessary.