Digital SLR musing

[srw]

I've been taking photos with a Pentax K10D for quite a long time now, and it does me well. I've got no pretensions to being a great photographer, and Picasa helps with a bit of cleaning up and cropping. I've been using the stock 18-55 and 50-200 zooms the camera came with; quite often I find myself pushing the bigger zoom lens to its fullest extent and getting frustrated that the bird or animal I'm trying to take a photo of is just a bit too far away.

The Pentax suits me, and I'm used to it. In the summer we're going up to Shetland and I'd like to have a camera with me to do justice to the wildlife without spending the earth. Without going all modern and getting a new camera (DSLR or the modern half-way hybrid), or forking out more than I want to, it looks as I've got about three choices. I could get something like a Sigma 70-300 zoom new for £150 or so. I could get a second-hand Pentax lens of about the same range for about the same price. Both would, I think, enable fully automatic operation, but if I wanted second-hand I'd need to hunt around a bit.

The third choice would be to get one of the longer (sometimes stupidly long) mirror or zoom telephoto lenses from manufacturers with mixed reviews and confidence-inspiring names like walimex or Opteka. They're all manual focus (which is probably OK if I'm looking at seals or otters, but not really birds unless they're roosting or swimming) and some of them claim to be usable with Aperture priority setting, which surprises me - I'd have thought they would all be entirely manual.

What does the collective wisdom of CC think?

 

[Crackle]

Being a Pentax owner (K5), my first thoughts are, which Sigma? They are not all equal and a couple of the 300 zooms are very poor. Mind you, even the poor ones are better than the Walimex type stuff which I wouldn't touch with your bargepole, let alone mine. Even something like the Pentax DA 55-300mm sounds like it might do. I always use this sight for evaluating Pentax lenses. Lots of user and staff reviews

http://www.pentaxforums.com/lensreviews/

There are lots of older lenses which you can pick up on ebay as well. Some manual focus but don't discount them for wildlife as often the autos don't focus fast enough, especially at the budget end.The K10 does support the faster focus SDM lenses in case you consider one.

 

[derrick]

Can you not just get a bit closer, On a serious note you will never be happy with a cheapy lense. Second hand would be the way to go.

 

[accountantpete]

Modern cameras with increased mega pixels will allow you to get better pictures from heavily cropped photographs - you might find that the 50-200 is ok on a K5 for eg.

 

[KneesUp]

I had a K10d and still have a K-7.

If you are happy with the quality of the K10d then I'd recommend getting a mirrorless (micro 4/3) camera instead. I switched to an Olympus OM-D EM10 principally because it's lighter and smaller. I lost the weather sealing of the Pentax, but it's on the EM5 and EM1 if you need it.

I get images that are as good if not better than the k-7 despite the smaller sensor, and as a bonus, it has a bigger 'crop-factor' (2x to 1.5x on the Pentax) so my old Tamron 80-210mm manual zoom with it's 2x teleconverter is something like the equivalent of 800mm on the Olympus. And like Pentax, Olympus put the image stabilising in the body, so it's useable handheld in good light. You can use pretty much any lens made for anything on a mirrorless camera - my Tamron adaptall to micro 4/3 mount was about £15. It also has 'focus peaking' to allow you to easily focus manual lenses.

You do lose out on depth of field - because the sensor is smaller, the depth of field is bigger, so it's harder to get out of focus backgrounds, but I got arond this by not bothering buying the standard zoom with it's relatively small max aperture, and bought a 20mm f1.7 fixed lens instead, which is compact, light, high quality and has a wide aperture.

I still have my k-7, but I've only used it a few times since I bought the Olympus.

 

[Cuchilo]

I have a sigma 70-300 and think its a great bit of kit . I also picked up an old 70-300 nikon lens for film . It was very cheap and i planned to use it with macro tubes but it works fine on the camera , i just have to focus manually .

 

[MichaelW2]

Wally Mex mirror lenses were all the rage when I was a nipper. You could get a garden bird to fill the 35mm frame, but distant birds were still small. They have funny artifacts from the annular aperture. The advantage was low weight and short length, so they are very handy, esp for travel, but they are quite fragile.

 

[fossyant]

My lad has a 75-300 Sigma on his Canon 700D, but he likes to use it in manual mode. It's the cheaper model, but he's a beginner. From what we've taken, it's good, very good. The autofocus can eat the battery though. The Canon STM 18-55 lens is much better in autofocus though.

 

[srw]

Many thanks to those of you with helpful suggestions.

They are not all equal and a couple of the 300 zooms are very poor. [...]
http://www.pentaxforums.com/lensreviews/
[...]Some manual focus but don't discount them for wildlife as often the autos don't focus fast enough, especially at the budget end.

A goldmine of information. Digging through my drawers I find I already have a manual 300mm zoom lens which seems reasonably decent, if extremely heavy - I think I got it quite cheap and second-hand 20 years ago. However, the camera body seems extremely sensitive to the focussing, and I haven't yet found out if there's a way to turn off the shutter lock when there's no focus found.

Modern cameras with increased mega pixels will allow you to get better pictures from heavily cropped photographs - you might find that the 50-200 is ok on a K5 for eg.

Ah! That's useful, and obvious once you mention it. It's certainly something to think about, although it is a bit more expensive.

I have a 500 mirror lens you could borrow to try out. It is a T mount, so you would need the right one as mine is Canon.

Oooh. Yes please. That would tell me whether the body is going to be so sensitive to manual focus as to make it impossible, as well as whether that sort of lens is going to do my head in.

As far as second-hand goes - I assume it's the usual caveat emptor story. Stick to well-reviewed sellers, or high-street chains with a reputation. Speaking of which, London Camera Exchange in Guildford seem to have a 320mm AF zoom from the film era in stock. I might manage to get over there tomorrow lunchtime.

 

[Crackle]

I haven't yet found out if there's a way to turn off the shutter lock when there's no focus found.

I'm not entirely certain what you mean there but I flip mine to manual focus on the side, depress the shutter button half way and turn to focus. Mine still bleeps when it thinks it's got focus, not sure if it's the same on the K10 but it might be and can be very useful. I use it a lot with the macro lens, an older film one with a huge focus range and auto is often fooled.

 

[srw]

I'm not entirely certain what you mean there but I flip mine to manual focus on the side, depress the shutter button half way and turn to focus. Mine still bleeps when it thinks it's got focus, not sure if it's the same on the K10 but it might be and can be very useful. I use it a lot with the macro lens, an older film one with a huge focus range and auto is often fooled.

That's it. With AF engaged I can only take a picture that the camera thinks is in-focus. With MF engaged I can take a picture that is completely out of focus. I suspect mine would bleep when it found focus, but the first thing I did when I fired it up was turn off all the bleeps. I get a little red square at the focus point and a green hexagon at the bottom of the viewfinder.

 

[srw]

Right, I can fetch it along Thursday week or sooner if you are working in London.

I'm in London Weds to Friday this week; when I'm back in the office tomorrow and have my diary in front of me I'll drop you a PM.

In the meantime I'll get on to ebay for the adaptor.

 

[KneesUp]

There is a 'release shutter on focus lock' option in Settings.

 

[mustang1]

Idk if all Sigma lenses are built to the same standard as someone who mentioned. I have an 18-35 1.8 which has great build quality but I still find it soft at maximum aperture opening and therefore I never open it all the way, preferring to start at f2.0.

It's a fact, but you might be better off looking for that used Pentax lens you mentioned. Since you need it in the summer, you have plenty of time to find a suitable one and if you didn't, you can always buy a new Sigma closer to the time of your holiday.

 

[mybike]

FWIW I have an old Russian 300mm mirror lens that I use, combined with a 2x multiplier on my Pentax with an adaptor. It doesn't give the greatest results but it certainly works. Bear in mind that most (all?) mirror lenses do not have aperture control.