Testing the Sony SAL75300 and Sony SAL18250 lenses

a57 with 75-300. f/8 @ 1/320th, ISO 800

I have continued to persevere with bird photography now that I have the Sony a57 and SAL75300 lens. On an APS-C sensor that equates to a 450mm equivalent fov (field of view), so I can get reasonably close to the wildlife.

But I can't say that I have been blown away by the performance of the Sony 75-300mm f/4.5-5.6 lens. It's certainly not 'tack' sharp (or even close) at the 300mm end - which is exactly where you want to be if you buy a telephoto lens. 

Case-in-point - the other evening I went back down to my local lagoon and followed a Grey Heron around for about an hour. He slowly became used to my presence, and so I got reasonably close. I managed to get some decent poses, fairly close up, but the light was low, so I had to crank the ISO up (again). I've had to do this on both occasions now and I'm beginning to think that the high ISO's are contributing to the overall 'softness' I'm experiencing with this lens?

Of the 250-ish images I shot of the grey heron, I kept just four. All the rest were just too soft. And the four I kept only just snuck through.

So I decided that on the next sunny day, I was going to go out in the middle of the afternoon, in bright conditions, and test the lens at ISO 100. On a tripod. With a 2 second delay on the shutter. At all focal lengths and apertures. Just to see what this lens is really capable of in a 'best case' scenario. So that's what I did this weekend.

And while I was at it, I thought I'd test the SAL18250 at the same time. Just - ya know - because. So sit back, relax, get a beverage, and lets find out how good(?) these two lenses are...

Greymouth Wharf from Cobden. Sony a57 with SAL75300. f/8 @ 1/250th, ISO 100 (at 135mm)

Looking across to the Greymouth Wharf area from Cobden Lagoon is a great place to do these kinds of telephoto lens tests. First because there's plenty of space to set up your tripod, second because it provides lots of details and contrast to lock in on, and third because it's only five minutes from my house 😆

I set up as outlined above; on a tripod, with 2 second timer, central focus point (yes, I auto-focused because that's what I do 99% of the time in real-world shooting conditions), steady shot off (because I'm on a tripod) and aperture priority mode so I could speed up the process, since I would be working through all the apertures at every focal point marked on the lens barrel. Easy...

After I had all the images, I opened them in Lightroom, looked through each set of f/stops for each focal length I shot at, and chose the sharpest of the set. The lenses 'sweet spot' at that focal length, if you will. Below, are the results.

The selections above are all central crops at 100%, made in Photoshop, with my 'normal' sharpening applied (Unsharp Mask Filter applied at 125%, Raduis 1, Threshold 0). It might be difficult to make out what's happening from a low-res internet image, so I'll just tell you what I found....

The Sony SAL75300 lens (at least my copy of it), is soft at 75mm across the aperture range - with f/16 being somewhat presentable. But this isn't a lens I will be shooting at the 75mm end. Period 

From 100mm through to about 250mm, the lens is what I would call 'acceptably' sharp from f/5.6 to f/11 - with f/8 more than likely being the sweet spot. Images within this aperture and focal range are sharp, without being 'tack' sharp. This lens never really manages tack sharp.

At 300mm there is a fall-off in overall sharpness again, although not as bad as at the 75mm end (where it really is horrendous). At the 300mm focal length, f/5.6 to f/8 is 'reasonably' sharp, but I would stick to the 100 - 250mm range for better performance if I could. The lens has other issues at 300mm as well, exhibiting high levels of purple fringing. This is very evident at f/5.6, becoming better (although not completely gone) at f/8. Even with 'Remove Chromatic Aberrations' ticked in Lightroom's lens correction tab.

I thought that maybe the 16MP sensor of the a57 wasn't doing the SAL75300 any favours, and it may perform better on the full-frame 24MP sensor of the a99? So, of course, I tested this theory as well.

Once again, I'll decipher the low-res findings for you...

Basically, nothing changes. Apart for the fact that the a57 crop sensor is producing a slightly bigger fov for equivalent focal lengths - the actual sharpness remains relatively the same. Yes, the a99 is ever so slightly 'cleaner' (ISO 50 compared to ISO 100), and maybe a hair sharper? Maybe. But nothing that makes it shockingly different.

So bottom line with the Sony 75-300mm f/4.5-5.6 (SAL75300); don't shoot at 75mm (at all), stick between 100-250mm and between f/5.6 to f/11 (let's just call it f/8 shall we?), and you should get 'acceptably' sharp results. Depending, of course, on your idea of 'sharpness'.

Cobden Lagoon. Sony a57 with SAL18250. f/8 @ 1/400th, ISO 100 (at 18mm)

Ok. So having established that the SAL75300 is really a 100-250mm, lets tackle the 18-250mm super zoom shall we!?

The SAL18250 is another one of those lenses that gets a bad rap from some reviewers. Actual users, on the other hand, often have some good things to say about this lens. Let's find out for ourselves.

Same process as above for the 75-300mm lens, although I changed position slightly so that there would be some interesting foreground in the image. Going through the apertures and focal lengths on this lens, what did I find?

Deciphering the above from what I see full-screen on my desktop computer at home, there's some good news if you want to use this lens as a pseudo landscape lens (as I do).

From 18mm up to 70mm, the lens performs very well in terms of sharpness - from f/5.6 to f/11. I wouldn't hesitate to use any combinations of the above. 18mm up to 35mm is even sharp through to f/16, which is a great result for us landscape photographers. Lens correction at the extreme 18mm end works well in Lightroom, and the corners are also nice and sharp. So at the 'wide' end of the lens, I'm very happy.

From 100mm up things change slightly. At 100mm sharpness is good from f/5.6 to f/8, and at 200mm from f/6.3 to f/8. At the extreme telephoto end of 250mm, only f/8 is what I would call 'acceptably' sharp.

So again, the good news for this lens, as a walk-around/travel/do-it-all superzoom, is that if you lock the aperture down at f/8, then practically all your images will be sharp. And if you want to use it as a landscape lens at the wider ends, then you have a great range of f/stops and focal lengths to choose from (up to about 100mm).

All-in-all I think this is a great result, and I'm well pleased with the SAL18250. 

I'm less pleased with the SAL75300, due to the less than impressive performance at 300mm (and 75mm). So does that mean I should just use the SAL18250 for everything and leave the 75-300mm at home?

Actually - no. Because again, based on my testing, the SAL75300 is a decent performer from 100mm to about 250mm. And the SAL18250 is an excellent performer from 18mm to about 100mm. Can you see the synergy here? The 75-300mm picks up where the 18-250mm leaves off. So effectively, with both lenses, I have decent (to sometimes excellent) performance from 18 to 250mm using both lenses. I did, of course test this theory out as well...

Hopefully you can clearly see that the SAL75300 is sharper from 100mm to 250mm than the SAL18250. Which means that it is still worth keeping both lenses, and taking both with me when I go out. If the 75-300mm lens was a big, heavy beast, then I'd think twice about bringing it. But it's not (it's only 460grams).

Am I disappointed with the lenses performance at 300mm? Yes, I am. And if I had the money, I would be changing it for either the Tamron SP 70-300mm f/4-5.6 or the Sony 70-300mm f/4.5-5.6 G SSM lens - both of which would, I believe, be infinitely better.

But I don't (have the money), so the Sony SAL75300, confined to shooting between 100 to 250mm, and from f/5.6 to f/8, will have to do during the meanwhile...

Sorry for the long post - and thanks for sticking with me this far (if you have). But it's a good, and important, exercise to do for yourself if you want to get the best out of your lenses. No matter what they might be. Lens testing doesn't have to be about boring test charts and brick walls. Get out in your natural environment and do some 'real-world' testing. I find this is always the best kind of testing. And the results may surprise, delight, or upset you!? 😄

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UPDATE: 15/04/22

Take all of the above with a grain of salt... 

I have recently discovered that my a57 isn't focusing properly - the sensor is probably out of alignment. So my overall impression of 'softness' is not surprising - and therefore all of the above is probably somewhat invalid!

Birding with the Sony SAL75300

In my last post I indicated that my 'new' Sony a57 had arrived, and I had already taken it out for a test-drive with the Sony SAL75300 (Sony A Lens 75-300mm f/4.5-5.6).

It's been a while since I've had a dedicated 'telephoto' lens for one of my systems, so I was keen to pop the 75-300mm on and give it a spin. I decided to do some bird photography down at my local lagoon. Unfortunately the clouds had rolled in and the weather was a bit overcast, so I had to bump up the ISO to give me some decent shutter speeds at the 300mm end of the lens.

Shagadelic! Sony a57 with SAL75300. f/11 @ 1/250th, ISO 800

From reading reviews of the lens, I knew that the Sony 75-300mm wasn't going to be the sharpest tack in the box - especially at the long end. So I made sure that I shot at around the f/8 to f/11 apertures, which should produce the sharpest images (a couple of stops shut down from wide open). As mentioned above, this also meant that I was having to bump up the ISO to give me fast enough shutter speeds. Hey ho - I guess I'll get to see how it performs at high ISO's as well then 😊

Lens elements in the SAL75300

The lens itself isn't anything to write home about. It is, after all, the cheapest telephoto to 300mm lens that Sony makes. It is also, apparently, a 're-packaging' of an old Minolta 75-300mm lens.

There are no special lens elements in its construction, and it's made mostly from plastic. Although that's not necessarily a bad thing. The plastic is of the modern polycarbonate type - which has proven to be very rugged and sturdy enough for most uses. Of course the lens elements are all glass, and the lens mount is metal. So that's a good thing. Fit and finish is also fairly impressive for such a cheap and cheerful optic. It's just a no-frills kinda product.

Unfortunately, the front lens element rotates, and the auto-focus is driven from the camera body. So it's not blisteringly fast, and it's not whisper quiet. Although it's also not turtle-slow, nor is it annoyingly noisy. It found focus and locked on reasonably quickly, so no complaints there. But it certainly ain't no G master! It also only cost me $149.00NZ. So there's that...

Swan family. Sony a57 with SAL75300. f/11 @ 1/100th, ISO 1600

I wasn't looking for birds-in-flight, so I didn't need to rely on the tracking on the a57. I did, however, set it to continuous hi-speed shooting so I could fire off a shot burst of images. This helps with getting sharpness, as at least one image in a series of burst should be sharp. Probably didn't need to have bothered with this approach looking back on the files. They are all 'relatively' sharp. 

I say 'relatively' sharp for a reason. Because from what I can tell from my brief outing, the SAL75300 never gets 'bitingly' sharp really, at any focal distance. I shot, as I said, at around the f/8 to f/11 apertures, and it seems to me from pixel-peeping that f/8 is the sweet spot.

It is probably hard to tell from the image samples above (click on the image to enlarge it in your viewer), but absolute sharpness (such as it is with this lens) peaks at around the 200mm focal length. Although it is a little difficult to gauge the lenses true capabilities, since all of the above were shot at ISO 1600 and are therefore a little 'noisy' (adding to the overall sense of softness). I will have to do a bit more testing in brighter conditions, where noise isn't a factor, to really get a sense of this lenses capabilities (and I will do).

All-in-all I wasn't blown away by the results from the SAL75300, although nor was I really expecting to be. I think that at f/8, all focal lengths (but especially below 250mm), will produce very good images up to A3 size. Beyond that, sharpness might start to become an issue?

Wading bird, Cobden Lagoon. Sony a57 with SAL75300mm. f/9 @ 1/500th, ISO 1600

The jury is out on this lens presently. I'm not sure that I got the best out of it on my first try, and I want to try again in better conditions. Ideally I would like to see how it performs at ISO 100, with a much 'cleaner' file.

The images here are not 'bad' per-se, they just didn't blow me away as much as I was hoping they would. And yet maybe my expectations were too high? This is, as has already been previously stated, Sony's cheapest telephoto lens up to 300mm - by far. So was there that much to expect in the first place? 

Trouble is, I'm coming from the micro-four-thirds system, where even the super cheap and plasticky Olympus 45-150mm f/4-5.6 (90-300mm fov in full-frame terms) is exceptionally sharp. So I've been a bit spoiled.

I certainly need to use the lens a few more times before I formulate any firm opinions regarding it's sharpness. And then again - sharpness isn't everything. Is it?

It's official - the Sony a57 is on its way

The deal is done...

I am now the proud owner of a Sony a57 SLT (single lens translucent) digital camera.

I sent my Olympus gear over to Christchurch this weekend past (thanks Levi for taking it for me), to be assessed for trade-in. Initially I was excited by a Fuji X-T20 body (see previous post here), but quickly realised I would get much more bang-for-my-buck if I went the Sony route (and I'm all for bang-for-my-buck!). You can read more about that here.

Late last evening (as I write this) I was contacted by the camera store owner who gave me a very good price for my Olympus gear (thanks Greg), and who also said the Fuji X-T20 was still waiting there for me! In the interim, I had been discussing other options with another member of his staff (hi Adam), and had come to the conclusion that the a57 was the one for me. This conversation obviously hadn't been passed on to the boss - who had even refused a sale for the X-T20 because he believed I wanted it. A quick email later, and I had outlined to Greg what I actually wanted as a trade-in for my micro four thirds gear. But how was I going to make it all happen?

My son is currently studying at the University of Canterbury (starting his second year in Computer Engineering), and Levi (who had picked up my camera gear in Greymouth) is one of his flatmates. So now Josh had my camera gear, and took it in today (as I write) to do the deal. I had outlined to him exactly what I had told Greg in my email of the previous evening, and had already received a reply from the store indicating that all would be ready when Josh got there. The stars were aligning.

Early this afternoon, I got a text from Josh saying he had the gear, and then about 10 minutes later I received an email from Greg at the store indicating the same. He also said that he had thrown in a spare battery (thanks Greg), and that I even had money left over that they would be happy to put into my bank account if I supplied them with a number. Which I immediately did. Wow! All this and money left over! How cool is that!?

So what am I actually getting, you may ask? What did I manage to score for my trade-in?

Well of course for a start there's the Sony SLT a57 body, with charger and batteries (x2). But it also came as a kit, together with the Sony DT 18-250mm f/3.5-6.3 super-zoom lens (see above). This will be an absolutely perfect walk-around lens that will probably be on the camera 80% of the time. At least whenever I'm capturing 'daily' life. Yes, I know that the f/3.5-6.3 variable aperture is fairly slow. But it was on my Olympus 12-50mm kit lens as well, and I loved that lens for its versatility. And optically it wasn't bad either.

The Sony DT 18-250mm (SAL18250) is an incredibly versatile lens - ranging as it does from 27-375mm in focal length (35mm full-frame equivalent). I will, of course, test it out once it is my hot little hands. It may not be a 'stellar' performer, but it also might not be that bad? I've tested the Canon 18-55mm kit lens before against an 'L' lens, and the 18-55 held its own admirably. So we shall see.

Add to this the Sony 75-300mm f/4.5-5.6 - another 'kit' lens that was cheap, but fills a niche that I like to have filled in my bag. I've written a few times before that I'm not a big telephoto shooter, but when I need it, I need it (if you get what I mean). I already know that this lens will be 'soft' wide open at 300mm. So guess what. I won't shoot it wide open at 300m 😆

With a 112-450mm focal length (in 35mm terms), as with the 18-250mm, it has a pretty impressive range. I'm sure that the 75-300mm will perform better than the 18-250 at the 200-250mm end (although that remains to be seen), so I've got it for two reasons. First because it was cheap 😂 And Second, because it will be the lens that I reach for when I want/need that extreme 450mm focal length (birds,sports,wildlife etc). I could be wrong, but I'm betting that the Sony 75-300mm will be 'good enough' for what I need it to do? Again, testing will be done.

Finally, it will all come in a Tenba 10L Solstice Sling backpack - in black. The Solstice is also second hand, but from what I can tell from the listing on their site, the only thing wrong is that it's missing its rain cover. Which I never use. So no big deal...

I wanted a sling-style backpack for the Sony gear, especially if I decide to carry most (or all) of it with me on a trip. The sling style backpacks are hugely versatile - offering the carrying convenience of a backpack, with the ease and accessibility of a messenger bag. When you get to somewhere you want to take a photo, simply 'sling' the bag around to the front for easy access to your camera. Ingenious! I used to have a Lowepro Sling backpack and loved it. So I'm looking forward to using the Tenba.

So there you have it. A camera, two lenses, and a backpack - plus change... Not a bad trade-in deal if you ask me.

The final stroke of luck... Macey's parents (my son Joshua's other flatmate) are going to Christchurch this coming weekend, and can bring the Sony gear back with them. So I haven't had to pay courier fees to get the gear there, or back again! Brilliant. It will mean that I don't get the gear until after this coming weekend - but never mind. Until then at least I've still got the Sony a99 to get along with. Not a bad fill-in option...