18-55mm Kit lens v 18-70mm

[bfitzgerald]

Quite interesting results on this one, and in complete contrast to Kurt Munger's comparison.
My copy of the Km 18-70mm DT v the Sony 18-55mm SAM

Shot on the A57 (when I had one!) Shot jpeg (should have done raw but hey equal for both lenses) no additional processing to either files

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[bfitzgerald]

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[bfitzgerald]

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The Sony does a bit better on the left hand top side for some reason.

CA is better controlled on the newer kit lens, the 18-70mm is well known for the cyan or red fringing at times. (here shown at a monster 300% mag)

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Overall my conclusion is that as DK said some time ago, there is no need to replace a good copy of the 18-70mm DT with the 18-55mm. I will I hope have another 18-55mm SAM to try shortly (when I actually get the A57 delivered again!) so I can see what the sample variation is there.

I've previously moaned about the Sony copies of the 18-70mm DT I had..about 3 if I can remember. All 3 were quite different and showed serious QC problems on an optical level, all 3 were unusable at max aperture wide or tele end (at 70mm they were awful at f5.6) one showed quite massive de centering. Same optical formula or not none of them were anywhere near the KM version I have used. As for Kurt's review and comparison, not knocking him but not all 18-70mm's are the same. If I had the 3 iffy Sony ones to compare to the 18-55mm the new kit would blow them away.

Compared to a decent copy of the 18-70mm, that lens IMO is sharper (based on my samples so far) than the new Sony kit lens. Though CA is better controlled on the Sony, it is actually quite good for close up shots with a higher magnification than the KM lens (not real macro but better than most and quite useful) AF speed is similar, the Sony is a bit quieter (this SAM motor was not as noisy as the first ones I tried) but it's not AF-S Nikkor quiet by any margin. Both lenses are to a degree satisfactory for a kit lens, the Sony is usable at max aperture, so is the KM lens across the focal range (usable being acceptable for a kit lens)

Both are fairly cheap build as per usual for all these types of lenses, so nothing to really compare there. Both are going to lose in sharpness v better lenses such as the various 17-50mm's and 17-35mm lenses (obviously) The Sony is unusual in that it's not as sharp centre as it is in some areas, it also doesn't seem to improve much by stopping down.
I'll have a look at the next copy of the 18-55mm SAM when that turns up.

[alphaomega]

Sure thing, a kit lens is a kit lens. Frankly, if you are into serious photography (in my humble opinion) any kit lens acquired say through a subsidised kit purchase should end up on ebay ASAP. I offloaded my Sony 18-70 and 18-55 lenses when I sold my two A350 cameras on ebay earlier this year. Long live my CZ16-80 I got with my first A700 and now survives on my A580. I also got rid of my Sony E 18-55 when I sold on my NEX-5. There are people out there on a budget who will buy these items. They are not bad by any means, bur certainly not in the Premier Class.

[bfitzgerald]

I'm posting this because a lot of folks will be starting out with a kit lens, and it was interesting to see the comparison between these 2 lenses. It also corrects some of the reviews that seem to suggest the new lens is vastly better than the older one (but granted based on a sample of one so far)

Some people will browse the forum and this might prove useful. Longer term members will of course have better lenses, and I do myself. But it's still worth putting it up I think.
I'd never usually advise anyone to get a kit lens def not unless it's a good deal ie the kit lens costing very little, or wanting an emergency spare lens that they won't cry about if it gets squashed. On the other hand I have to say I was never unhappy with the 18-70mm, and whilst I acquired better lenses down the road, it was capable enough and better than expected for a kit lens.

[Greg Beetham]

Well Barry it looks pretty cut and dried which lens of the two would go with a body for sale, from here anyway. That 18-70 doesn’t seem to do a bad job at all although the JPEG’s look a tad melted in places, but I think we can safely say that’s not a problem with the lenses.
Greg

[bfitzgerald]

Greg when I get the "new" A57 back I'll do a raw/jpeg thing, but you can be pretty sure that the results are quite stark. From my own quick assessment I'd say avoid jpegs at all cost. I've moved to lossy dng conversion for some stuff, to cut down on the file sizes and as a jpeg replacement (either that or convert the raw to jpeg with LR and dump the raw files). Sony are kicking out 16mb files for ARW, but never lower than that, the D7k I had would be able to compress raw for some types of shots more efficiently.

I won't deny the A57 overall is better for me than the Nikon, but some credit to Nikon their jpegs completely destroy Sony across the board. You can with confidence shoot at all ISO speeds in jpeg on that model, and the D90 was good too (both set to NR off) Sony are just too heavy handed on NR processing and even setting it on low makes little difference. The downside to this is that some stuff on the A57 is practically redundant, the zoom function, DRO and anything else that uses jpegs.

But that's for another day..but yes the jpegs are that bad even at ISO 400 you're losing quite a lot of detail. At higher ISO levels it's blow torch and candle wax. It's true that the raw files are better on the Km5d too esp high ISO (at lower ISO levels you can't tell the difference in details), but even at ISO 1600 I was not too unhappy with the KM jpegs. Sony's jpegs are no better than the A200 was (ie they suck)

[KevinBarrett]

I replaced my 18-70 not for the image quality, but for the fact that its plastic mount was depositing little curly plastic shavings on my sensor. I do like the images I took with it though, not least for their very simple barrel distortion.

[classiccameras]

I agree with Barry, the Jpegs I get from my D5100 & 18-105 and my old D5000, [same sensor as the D90 and regret selling it] were superb right across the board, only beaten in my opinion by my old Olympus E-510 and E-450 cameras, apart from other issues with the older Olympus cameras, their Jpegs are hard to better and I score them the best along with Fuji.

In the Photozone.de test report on the Sony 18-70, they gave it rather poor scores, but that was reflected in the price apparently, however, they may have had a poor example which can happen at that end of the kit lens market.

I'm quite happy with my Sony A-37 Jpegs but I mostly only shoot at 100 - 400 ISO for landscapes and don't print bigger than A-4, however, nearly every test report on the Sony SLT cameras gave them top marks [mainly the 37 & 57] for IQ but slagged them off for over aggressive noise control which blurred detail at higher ISO settings with no user off switch.

No camera seems to tick all the boxes for me any way, but my little A37 gets close, but then in opposition, the Canon gets most things right for me [but not necessarily for others] and is probably where I might end up if I need to jump ship in the future.
Pete

[bfitzgerald]

The NR really eats in about ISO 400 and up with Sony (that's my take) at ISO 100/200 you'd probably be ok with the jpegs out of camera or if you're into heavier NR processing. I just find for print noise is far less visible at normal sizes, and you get better prints with more "bite" and less NR. I don't do a lot of NR to raw it's mostly the colour noise you want to get rid of.

Sony seem to feel that wiping out the grain like noise is the way to go, hence the stronger NR. As with Nikon I think the only sensible approach is to let the user decide so I shot NR off with the Nikon's when I had them, and the jpegs were good to the point where you'd be happy enough using them even in high ISO.

On the kit lenses I'd say the 18-55mm is "ok" for what it is, though the Nikkor 18-55mm is a bit better in my view (ones I tried) but that has it's own issues can't really cope with the new 24mp sensors very well, it's got quite a bit of CA at times, the Canon one is not bad either. All are as you expect cheapo build and not amazing, but acceptable. Pentax have the worst kit lens I tried a few copies decent enough stopped down wide end, but soft focus effect and very disappointing above 35mm.

An acceptable kit lens should be able to produce reasonably sharp shots across the range without stopping down loads. The Sony 18-70mm's I tried (and I think it was 3/4 I used) all were very poor, one was so badly de-centred I've never seen anything like it. All were unusable at the tele end below f8 (just horribly soft) that leaves you with a slow lens that's very slow as you are forced to stop down and quite a lot.

So I'm not surprised that the 18-55mm SAM get's better reviews v the sony 18-70mm because the samples vary so much and all the ones I tried were grossly inferior to the Km one I have. The KM version I have is slightly sharper right side than left, but it's not horribly obvious and it delivers pretty decent images and cost effectively nothing. Certainly satisfactory for a kit lens and I've used it quite a bit.

I liked the Nikkor 18-105mm it's a pretty sharp lens, bar the usual fairly hefty distortion both ends was a good standard "super kit" type lens. But I hated the plastic mount and live in fear of it breaking. The wobbly lens hood also annoyed a bit but overall pretty good.

As for lens reviews I tread with caution samples can vary a lot, and almost ever review I've read of Kurt Munger's does not tie up with my own experience of the lenses I've used. Not to knock him he can only test what he has, but some as so wildly different you'd think he was either so unlucky with bad samples, or something is wrong in his method or testing.

[classiccameras]

I read in some of Kurt Munger's lens reviews that he aknowledges the fact that the sample he is testing may not be a good example.

Photozone.de liked the Sony SAM 18-55 kit len with the exception of the build quality and plastic mount.

Absolutely agree about the Pentax kit lenses and even some further up the pecking order, not very good. Hoya did make most of the Pentax logo lenses with the odd exception, that may have changed now that Ricoh are the parent company. If I had a Pentax I would stick to Tamron and Sigma. Canon 'kits' were a bit dismal as well. Olympus probably on average make the best kit lenses for optical performance and build quality, but they are more expensive.

Nikon lenses do seem to be more consistant performers than other brands and this has been commented on by several review sites. My Jpegs from the D5100 + Nikkor 18-105 are 'stunning' and I would be hard pressed to get much better elsewhere. Having said that, my A37 fitted with the KM 17-35 are equally good up to 400 ISO, after that the Nikon leaps ahead.

Pete

[bfitzgerald]

The original Canon 18-55mm was frankly astonishingly bad, I tried a few of those and I'd be reluctant to use it as a door stop let alone an optic!
The newer Canon kit lens is quite decent though I've yet to find a sample as good as Photozone say their one was. The Nikon 18-55mm not bad but I think it struggles over 12mp, and at 24mp bundled with a D3200 forget it just doesn't happen at all. 18-105mm is IMO quite a good lens and a step up over the 18-55mm, but again most of the lenses are now starting to struggle at bit with the higher resolution sensors.

In summary the Sony kit 18-55mm is "ok" but no more than that (ok as in being at least usable unlike their older 18-70mm) I think most folks are better off getting a body only option and putting a bit more cash towards something a bit better. As for Kurt I appreciate the effort he makes, but again I've either got some really good copies of multiple lenses, or he ended up with a few not so good ones.

[classiccameras]

I decided to use the Konica Minolta 17-35 F/2.8 D lens [re badged Tamron] as my standard kit lens and supplimented the longer end with a Minolta 24-85. I get very good results from both lenses so my original Sony 18-55 kit lens just sits in the photo drawer. This brings me on to whether I should switch off the front curtain or not on my A37 when using Minolta, Knonica lenses. Michael Hohner in his excellent but confusing article on front curtains has not been very conclusive.
I believe Greg Beetham got involved in the front curtain off/on debate as well.
Has any one got a recommendation.
Pete

[Greg Beetham]

Yes I did CC I was just agreeing with the excellent observation he made about the shading effect, the only thing I was offering was that the shading effect would be a lot less if the mechanical shutter was a lot closer to the sensor than it is. (and perhaps it was out in front by that extra distance because of the IBIS)
You have one shutter curtain (electronic) on the actual sensor behind the OLPF and the other curtain is mechanical well forward of the sensor which alters the angle of lighting going through to the sensor from one end of the travel to the other, more pronounced at faster shutter speeds. Whereas when you use both mechanical curtains they are in the same plane with each other and there is no progressive shadowing effect.
The only thing I heard about earlier lenses was they may not respond (iris) as quickly as more modern lenses, there might even be the odd sticky diaphragm maybe in older lenses as well.
As far as your lenses go I guess the only way is to try them out at the higher shutter speeds and see if there are any variations of exposure at medium f-stops, then you’ll know one way or the other.
Greg

[classiccameras]

Hi Greg
Thanks for that, I seem to remember some one saying there may be some iris lag on older Minolta and KM lenses, not so much because they were sticky etc, but the very nature of their design was slower, but later Maxxum lenses were OK. It may become more noticable on flash photography although I can't see that. So far my pictures seem to have even exposure across the whole frame with first curtain on or off. I also remember Kurt Munger saying play safe and switch it off with older Minolta and KM lenses.
If I remember rightly, the KM 17-35 F/2.8 D lens was the up market kit lens on the very early KM digital DSLR's such as the KM7, so hopefully it should be OK on later SLT cameras with out touching the first curtain setting. Could be wrong though.
Pete