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11-19-2008, 02:28 AM   #1
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PLEASE HELP Need Advice re Lens Options etc

Hi there,
I'm new to digital SLR photography and have a K10D with the Sigma 18 - 125mm lens.
I also have a 35mm SLR the Z20 with Sigma 35- 80mm and Sigma Aspherical 28 - 200mm lens.

I am told that these 2 lens are compatible with my K10D but am not sure about the pros and cons of using them.

The standard 18 - 125mm lens that came with the camera has been OK for general outdoor photography but as soon as I have atempted to take indoor shots from a distance like at my daughter's basketball or school functions I get really poor results (hand held) as the lens just doesn't seem to work well at all in low light unless I could set up and use a tripod.

Anyone who can explain the technical reasons for this and offer advice as to another lens to purchase would be greatly appreciated. Would an 18 - 55mm for example be a good starting point?

I take mainly outdoor landscape shots but also indoor family and friends shots as well as the odd indoor function ie sport (as mentioned)

I have just found a very good condition used Sigma 18 - 50mm f/ 3.5 - 5.6 DC lens for sale for under $200 AUD here in Sydney. Would this be a useful lens for me to grab now?

Thanks very much


Last edited by mike star; 11-19-2008 at 05:26 AM. Reason: Added information
11-19-2008, 07:47 AM   #2
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If you are shooting action, indoors with poor light conditions, you would want a "faster" lens. These are lenses with an f stop of at least 4 and prefferably 2.8.

Unless you can use a flash, these variable ap. lenses just don't open wide enough.

SR is helpful indoor.


Dave
11-19-2008, 09:58 AM   #3
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Hi Mike - I'm no expert - but these are some things that might help.

A newbie to a newbie if you will :-)

When you take photos indoors at a distance. This means you will likely zoom in to the action. When you are zoomed in the aperture on the lenses you have will likely become smaller (by design) thus allowing less light in meaning the shutter speed needs to be slower. Means it stays open for longer. Means you are more likely to get blurred photos.

Possible zero cost solution. Make sure Shake reduction is turned on on your camera. This will help - especially if you are shooting handheld rather than a tripod. Secondly change your ISO speed setting. Maybe start with 800 or 1600 even. the higher it is the better it will be at taking photos in lower light conditions. (There are downsides like 'noise' in the pictures - but we could end up writing a book here!)

Also the three picture scenarios you describe are all very different!
'outdoor landscape shots' - probably suited to your 18-125 lens at the 18mm setting for a nice wide angle. You are outdoors so you should have enough natural light.
'indoor family and friends shots' - again here - check your shake reduction setting and try a higher ISO. (Assuming you are not going to use the flash). Also check your 3 lenses to see which one has the lowest 'F'/aperture size. As Pentkon says - for low light, the lower number the better.
'indoor function ie sport' - we covered this above.

I think those two spare lenses you have from your old camera sound fine. They would have the Pentax bayonet fitting and would slot right on. I don't own those lenses - so correct me if I'm wrong somebody. But I would put those on the camera body and see if your results are any better. But from googling them I don't think the 'f' stop will go much lower than your 18-125. But I think looking at the shake reduction and ISO might be a good starting point.

Don't buy that 18-55. It will offer little if any value over your existing lenses.

Hope that helps.
11-19-2008, 10:31 AM   #4
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QuoteOriginally posted by mike star Quote
The standard 18 - 125mm lens that came with the camera has been OK for general outdoor photography but as soon as I have atempted to take indoor shots from a distance like at my daughter's basketball or school functions I get really poor results (hand held) as the lens just doesn't seem to work well at all in low light unless I could set up and use a tripod.
So I assume you mean, you couldn't get a fast enough shutter speed to eliminate blur. As another poster mentioned, that's because it doesn't have a very large maximum aperture. Although you should at least be sure to turn the ISO up as high as you can stand, and make sure you are using the largest aperture the lens does support (f/5.6 when zoomed all the way to the telephoto end). Consider underexposing the shot if necessary to get even a faster shutter speed, and brightening the picture in post processing.

I doubt either of the older lenses you have would be any better here. A lens with large maximum aperture (smaller f-number, like f/4 or f/2.8) is what you need. If you can handle manual focus and don't need the lens to zoom, you can get used 100mm, 135mm, or 200mm in that aperture range lenses for very little (under $100 each). But it you want autofocus and zoom capability, then it will cost a lot more to get a lens that is "fast" enough.

QuoteQuote:
Would an 18 - 55mm for example be a good starting point?
No. Not only is it no "faster", but it only goes to 55mm, and I'm assuming you are using the 18-125 more toward the 125mm than the 18mm end.

QuoteQuote:
I have just found a very good condition used Sigma 18 - 50mm f/ 3.5 - 5.6 DC lens for sale for under $200 AUD here in Sydney. Would this be a useful lens for me to grab now?
No. this lens is pretty universally considered to be far worse than the Pentax 18-55, which costs no more. But really, neither of these would give you any advantage over what you've got. If you need faster shutter speeds, you'll need a larger maximum aperture at the focal lengths you actually use at the games, and I'm guessing that's not even in the 18-55 range.

11-19-2008, 12:55 PM   #5
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Try fast primes, theses are non zooms (you can still use your legs as a zoom mechanism), hence usually a couple of stops faster, i.e. 50mm f1.4 of F1.7.

These can be picked up at reasonable prices secondhand, get one just see what a huge difference it can make.

If you like these, you can go on to get some longer fast primes, but these do start to cost more money.

Last edited by Kerrowdown; 11-19-2008 at 03:11 PM.
11-19-2008, 02:28 PM   #6
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Thanks very much

Hi there,
Thanks to those of you who replied and gave me the benefit of your experience. I will look for a prime lens with f2.8 and see what I can find and also maybe a good used zoom with F4 or lower as well.

With the older 35mm lens on my Pentax Z20 35mm SLR I used to get good indoor shots and got some great shots indoor (old buildings, churches etc) and outdoor when holidaying and touring in the USA 10 years ago. Maybe the 35mm technology was more capable of giving better results with those lens f3.5 - 5.6 ??
11-19-2008, 04:30 PM   #7
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QuoteOriginally posted by mike star Quote
I have just found a very good condition used Sigma 18 - 50mm f/ 3.5 - 5.6 DC lens for sale for under $200 AUD here in Sydney. Would this be a useful lens for me to grab now?

Don't bother, this lens always gets poor reivews. See, for example,

PentaxForums.com Third-Party Pentax Lens Review Database - 18-50mm F3.5-5.6 DC (AF Lens)

Dan.
11-19-2008, 04:53 PM   #8
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QuoteOriginally posted by mike star Quote
With the older 35mm lens on my Pentax Z20 35mm SLR I used to get good indoor shots and got some great shots indoor (old buildings, churches etc) and outdoor when holidaying and touring in the USA 10 years ago. Maybe the 35mm technology was more capable of giving better results with those lens f3.5 - 5.6 ??
On the contrary, without SR, it's *extremely* unlikely you'd get better results in low light from film than digital. Assuming the same ISO, yu'd be getting the same shutter speeds, and nothing abut film would make those shutter speeds work any better. More likely, you just didn't "pixel peep" to the same extent, and if it looked good on a 4x6" print, that was good enough. Whereas with digital, we're constantly viewing things on screen at many times that size, thus exposing flaws in our pictures that wouldn't be so noticeable in 4x6" prints.

Now, it may be that you were *not* in fact getting the same shutter speeds with your K10D, because of how your were using your camera. What ISO were you shooting? And what aperture? Do you think you might have possibly been using *higher* ISO film 10 years ago, thus yielding faster shutter speeds?

Posting some examples from both camera would be interesting, althoug of course you'd be unlikely to remember for sure what ISO, aperture, or shutter speed you were using 10 years ago...

11-19-2008, 05:32 PM   #9
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Hi Mike,
If you're shooting basketball pictures and can get courtside, I would go with the fast 50. To get a good 8x12 or more, you are going to need at least 1/200s shutter speed and 1/400 would be better.. unless you're shooting pictures of free throws. I'm not a pro, (by far), but I've seen a lot of pro shots that tell the shutter speed, and hardly any are below 1/800 of a second. If you're shooting from the stands at f5.6, f2 would give you an 8 times faster shutter speed, f1.4... 16 times faster.

I have a dusty Pentax A 50 f2 I would give you If you want it.

Mark
11-20-2008, 12:13 AM   #10
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QuoteOriginally posted by Mark2100 Quote
Hi Mike,
If you're shooting basketball pictures and can get courtside, I would go with the fast 50. To get a good 8x12 or more, you are going to need at least 1/200s shutter speed and 1/400 would be better.. unless you're shooting pictures of free throws. I'm not a pro, (by far), but I've seen a lot of pro shots that tell the shutter speed, and hardly any are below 1/800 of a second. If you're shooting from the stands at f5.6, f2 would give you an 8 times faster shutter speed, f1.4... 16 times faster.

I have a dusty Pentax A 50 f2 I would give you If you want it.

Mark
Thanks very much Mark for your advice and the offer. I wonder what it would cost me to have it shipped to me here in Australia. My Zip Code is 2777 in Winmalee, New South Wales.
If you could check with your Postal Service or UPS I could send you the money plus whatever you want for the lens. It would be good to have it so that I could experiment before purchasing something specific to the Digital SLR.
Once again,
Thanks!!

Last edited by mike star; 11-20-2008 at 12:14 AM. Reason: Spelling
11-20-2008, 04:01 AM   #11
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These lens are currently up for auction here on e-Bay in Australia. Does anyone have an opinion on any of them?

- Pentax 50mm f1.4

- Pentax SMC A 50mm f1.7

- Ricoh Pentax K Mount 50mm f 2.2

- Pentax 645 75mm f2.8 A

- Pentax SMC FA 50mm 50mm f 1.4

- Pentax P - FA 24mm f2 ED

- Pentax SMCP-FA P-FA 50mm f1.4 AF

- Pentax M 50mm f2 MF (Is this like yours Mark?)

Thanks
11-20-2008, 10:38 AM   #12
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QuoteOriginally posted by mike star Quote
These lens are currently up for auction here on e-Bay in Australia. Does anyone have an opinion on any of them?
None of them are really long enough for sports photography. But assuming you are more interested in general low light work, I'd probably pick up the A50/1.7, since it is fast, good, and cheap. But if the FA50/1.4 isn't much more, it's hard to pass up autofocus.

You'll need to figure out for yourself what focal lengths you are most interested in, though. For me, 50mm is kind of long for most indoor use (but great for some kinds of portraits!). 24mm would be way too wide most of the time. If I were to get just one fast lens for general indoor use, it would be in the 35-45 range.

QuoteQuote:
Ricoh Pentax K Mount 50mm f 2.2
Be careful of Ricoh lenses, as they often have some extra hardware that causes them to get stuck on Pentax DSLR's. Browse around for info on that first. But really, I can't imagine reaosn why this lens would be preferable to any of the Pentax 50's.

QuoteQuote:
- Pentax 645 75mm f2.8 A
Although I don't know anything about this one in particular, note that "645" lenses are a different type of mount and require an adapter. But that could be interesting for portraits and maybe some sport uses.
11-23-2008, 10:29 PM   #13
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Hi there,
I have looked at all the advice you guys have given and I have investigated the Auto ISO setting on my K10D. It was set with a very limited range. I have now re set that with a broader range and have taken some general indoor shots still with the camera on Auto ISO and got better results immediatley.
Now I have also taken the camera off Auto ISO and have just experimented with various manual settings and taken a series of indoor shots and again got much better results.
Using a higher but still mid range setting produced a darker image that was able to be "tailored" using one of the many photo shopping programs out there. Using a higher setting 800+ produced a better initial image but when enlarged showed signs of noise that on shots taken at the lower settings were not so apparent if at all.
I'll keep experimenting and learning and once again,
Thanks for all your guidance etc.
A special public thank you to Mark from Oklahoma for his generosity!
Cheers
Mike
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