Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
11-10-2007, 06:45 AM   #1
Junior Member




Join Date: Oct 2007
Location: Melbourne
Posts: 26
how much better would a 50mm prime really be?

I have a Sigma 18-200mm DC 3.5-5.6 atm and use 50mm focal length for alot of protaraits i do

i'm just wondering how much better a 50mm 1.4 would really be?

the images i take are aready really good and sharp and have plenty of detail i my opinoion

i'm just not sure that spending another three hundred dollars to upgrade to that lens is really worth it

whats the difference really? apart form the faster aperture steting which really isnt' all that useful anywya, because f5 is enough, but i guess it would help in low light situations i guess

heres a sample pictures from my 18-200 and i think its perfect. how much better can it possibly get?





cheers fellas

11-10-2007, 07:26 AM   #2
Forum Member
Jimsi777's Avatar

Join Date: Sep 2007
Location: Virginia
Posts: 75
I like your first picture, has good white balance,

You could try buying a manual focus Pentax f 1.7 prime 50mm for around $50(ebay), these lenses had some great reviews, even with auto exposure 'A' lens for $70 with manual focus, I think the contrast, crispness, natural colors, less distortion and detail cant be beat with my f1.7 yet a side by side comparison would show you how much better the prime would be.

Even my 1.7 has to much softness for my taste, a 1.4 would be 1/2 stop faster?? giving you more softness and some possible preceived focus issues, you'll probably open it up to more than f/1.4 most the times anyway.

Your background bokeh would be nice with a 1.4

Last edited by Jimsi777; 11-10-2007 at 07:41 AM.
11-10-2007, 08:05 AM   #3
Pentaxian
Duplo's Avatar

Join Date: Nov 2006
Location: Copenhagen
Photos: Gallery
Posts: 916
Tough question to answer.

You are doing pretty well with the lesn you got already.

Now it it will allow you to shoot portraits where you are not able to shoot them today.

I have several shot at ISO 800, f2, and a shutter in the 1/1- - 1/30 range...
Your lens would simply not allow that.

So what you buy is flexibility, a sharper lens, a lens that IMO has a better rendering and a lens that is pretty close to distorsion free (not that it matters too much for portraits)

Now if that is worth the 300 USD to you is an entirely different matter that only you can answer.
another option to consider is one of the fast constant aperture zooms, but they are priced differently. It all depends on how you prefer to work.

All this said, I think you are producing very nice results with the lens you have.
11-10-2007, 08:43 AM   #4
Veteran Member




Join Date: Sep 2006
Photos: Gallery
Posts: 5,713
My portrait lens of choice is actually an OLD 55mm f1.8 K-mount lens.

If you can find one they're very affordable.

11-10-2007, 09:14 AM   #5
mer
Senior Member




Join Date: Nov 2007
Location: Greece
Posts: 237
hey

hey I like the first pic ... good colours and colour balance as someone pointed out.

well.. I would bet a 50mm prime let's say stopped down to 5.6 would have better resolution uncropped and resized ( your pics are resized ( first cropped aswell ) ) and of course better corner resolution . Another thing is nothing beats the bokeh of a 50mm 1.4 and its low light shooting capabilities ... You can't comparea a f/4 or f5.6 ( what is the aperture of your lens at 50mm ? ) to f1.4 ... at low lighting situations the difference is day and night ( literally hehe ) and every bit helps ( even the extra half f-stop between f1.4 and f1.7 ) . So unless you desire superb bokehs , good low lighting capabilities and superb ( even corner to corner ) resolution ( at f4-f5.6 ) so you can print large prints , then don't get a 50mm prime .

Another thing I would like to mention is that even if your first pic is technically very good, I can see all the skin imperfections , that distracts me quite much , which is not flattering for your model . So a f1.4 lens , set at 1.4 ( which is softer at those apertures ) would give you a more pleasing result with the same lighting conditions ( window lighting from the side ) . Noone wants to see all the skin imperfections at close up portraits ... unless the model has had make-up from a professional make up artist or has a perfect skin

Sorry for my bad english , I hope you understand what I am trying to tell you . I am Greek. And your friend or model is very beatiful by the way

Have fun !

Last edited by mer; 11-10-2007 at 10:57 AM.
11-10-2007, 03:22 PM   #6
New Member




Join Date: Nov 2007
Location: Graz, Austria
Posts: 15
hi!

i have a k100d, the kit and the da 50-200. i wanted something for low light pics without flash and something with nicer bokeh. additional to that it shouldn't too expensive.
therefor recently i bougt a fa 50 1.4 and i'm very happy with it. it is a pleasure to use it.
but the small shallow can be very trick at f 1.4 . and it is not so sharp. but on 2.0 and further it will be sharper a sharper.
and for me, it is another experience to photograph with a fixed focal lens. the pics look in some way different. it makes addicted.

greetings
mario
11-10-2007, 06:40 PM   #7
Veteran Member
Finn's Avatar

Join Date: Feb 2007
Location: Phoenix
Photos: Gallery
Posts: 1,056
Another thing to think about when shooting portraits at f/1.4: the depth of field can be TOO narrow if you are fairly close to the subject. I have lots of photos where the eyes are in focus and the nose is out of focus. Sometimes that can work well, but sometimes not so much. Here is one that was taken with an FA 50/1.4 at f/2.8, and you can see how narrow the depth of field is already:

11-10-2007, 06:52 PM   #8
Junior Member




Join Date: Oct 2007
Location: Melbourne
Posts: 26
Original Poster
i've read that there is some distoriotn of those expensive 50mm 1.4 and the best aperture to use on them is about f4 - f5 anyway

and i'm not understanding what you mean by softer pictuers and less skin imperfections of the model

i thought the point of having a good camera/lens is seeing every little itty bitty detail even if the detail isn't flattering

she did already have a bit of make up on

that first pic turned out quite well i must admitt, i was tyrign to do a bit of "girl with pearl earring" thing, it was one of my first ever pictures taken with my camera, and one of my first ever using a dslr

i suppose it would just help with sharpness and less distortion right? and allow low light shooting. i'm having alot of trouble at the moment, when i'm shooting indoors with just the one tungsten lightbulb.

i think that shot was taken at 80mm now that i think about it, the lower f stop it can go to is about f5, which is what i used to for that picture

thanks for the replies fellas

11-10-2007, 07:17 PM   #9
Forum Member
Jimsi777's Avatar

Join Date: Sep 2007
Location: Virginia
Posts: 75
Taking pictures is an art form and a little blur or no blur is part of what I look for at times when I shoot pictures. Cheap point and shoot cameras dont blur the background (all seems in focus becuase of a small aperture of cheap cameras) we can do the same or add a bit of Bokeh and or a little blur in the depth of field ...

The lower the F/stop the wider open the aperture becomes and more backing and depth of field blur (nose may be focused, not ears, for example) the higher the f/stop the less blur and better focus of foreground and background
11-10-2007, 07:51 PM   #10
Veteran Member
Eaglerapids's Avatar

Join Date: Apr 2007
Location: Idaho,USA
Photos: Gallery
Posts: 1,588
Jimsi is so right about Ebay. You don't have to pay $300 for a very nice 50mm prime. I just scored a SMC Takumar 50/1.4 with both caps, a UV filter, and a Pentax polarizing filter for $64. The Super-Takumars generally go cheaper and the 55/1.8's can be had for a song if you're patient and wait for the right auction. Of course you would need an adapter with the screw mounts. A few months back I bought a M-50/1.7 for $40. These are manual lens but I love working with them. You need to have your camera setup properly.
I see you're in Australia so these prices may be more for you:-( but I guess they would scale accordingly.
You're taking some very nice portraits (beautiful model) and I think you would be well pleased working with a good prime.
11-10-2007, 07:55 PM   #11
Veteran Member
Finn's Avatar

Join Date: Feb 2007
Location: Phoenix
Photos: Gallery
Posts: 1,056
QuoteOriginally posted by lordson Quote
i thought the point of having a good camera/lens is seeing every little itty bitty detail even if the detail isn't flattering

i suppose it would just help with sharpness and less distortion right? and allow low light shooting. i'm having alot of trouble at the moment, when i'm shooting indoors with just the one tungsten lightbulb.
On your first point, I would say...maybe. If you want heaps of (mostly polite, at least on this forum) opinions, I would suggest starting a thread on just that topic. It might be interesting to see what people think.

On your second point, you are absolutely right. A 50mm f/1.4 lens will be able to take photos in 1/16 the amount of light as the kit lens. That is a MAJOR difference. And the FA 50/1.4 can be had for under US$200, which makes it the most ridiculously good bargain of the entire Pentax lineup.
11-10-2007, 09:08 PM   #12
mer
Senior Member




Join Date: Nov 2007
Location: Greece
Posts: 237
QuoteQuote:
i've read that there is some distoriotn of those expensive 50mm 1.4 and the best aperture to use on them is about f4 - f5 anyway
Yes the f1.4 is not distortion-free but the f1.7 is practically flat-field . Remember that you want to buy a f1.4 or f1.7 ONLY if you want shallow depth of field ( with good bokeh ) and shoot in low light situations .

QuoteQuote:
and i'm not understanding what you mean by softer pictuers and less skin imperfections of the model"
I mean that you don't usually want to shoot portraits with your most sharp lens you have . Showing skin imperfections is not , generally , good . Pentax used to sell soft lenses especially for portraits .

QuoteQuote:
i thought the point of having a good camera/lens is seeing every little itty bitty detail even if the detail isn't flattering"
Yes you generally want the lens/camera to be as razor sharp as it can be ... but not for close-up portraits .

QuoteQuote:
she did already have a bit of make up on
Yes she did but the make up didn't cover her skin imperfections , a professional make up artist would do that .



To answer your first question , how much a 50mm prime would be better ... well it would be a quite better , especially a f1.7 ( which is practically flat-field ) which would deliver corner to corner sharpness . Your lens maybe sharp at f5.6 ( mostly all lenses are sharp at f5.6 ) but one doesn't have all the light whenever he needs it . For example in indoor situations or inside a bar or in a cloudy day or during the afternoon/night .

So for example a 50mm f1.7 would give the same sharpness ( possibly more ) at f2.8 as your lens gives at f5.6, which can determine a crisp image from a blurred image if there is not enough light . Also better corner to corner sharpness . Also , a 50mm at f5.6 would deliver better results to your sigma if you were to print at A4/A3 . If you are going to resize your pics to small resolution you won't see much difference ... you would be better with a point and shoot camera . Also nothing beats the shallow depth of field and bokeh a fast lens can produce . I hope I have answered your questions .

Have a look here for a review :

Sigma AF 18-200mm f/3.5-6.3 DC OS (Canon) - Photozone Lens Test Report / Review
11-10-2007, 11:32 PM   #13
Veteran Member
roentarre's Avatar

Join Date: Oct 2006
Location: Melbourne, Australia
Posts: 11,794
Well, besides whats being said, a fast aperture really gives you the freedom to get high quality shots with a good narrow DOF to blurr the background. The consistent image performance of 50mm prime is crucial here.

Your first shot is beautiful revealing the skin texture due to the side lighting. Most lenses are capable of achieving that when the lighting is right.

To shoot protraits with various lighting situation, a fast prime gives you more possibilities.



p.s. you are from Melbourne too. Interested to join melbourne pentax group too?

Cheers

James
11-11-2007, 03:11 AM   #14
Inactive Account




Join Date: Mar 2007
Photos: Gallery
Posts: 3,675
QuoteQuote:
I have a Sigma 18-200mm DC 3.5-5.6 atm and use 50mm focal length for alot of protaraits i do

i'm just wondering how much better a 50mm 1.4 would really be?
I am not sure if that is what you really want. If you are satisfied with the first portrait it was not shot at 50mm, or anywhere near that focal length. The EXIF data reveals this; "Focal Length in 35mm Film = 139". That equates to 92.6 mm. I don't mean to overstate the obvious but, maybe a different length prime would be more suitable.

My humble opinion is that zooms are perfect for travel, snap shots and sports. Serious portraiture photography requires a prime lens. You are not chasing your subject with your lens so the zoom is not necessary. A prime, like many have stated before me, will give the added bonus of having a larger aperture which will allow for more varied lighting conditions and a much smoother background.

Last edited by J.Scott; 11-11-2007 at 03:24 AM.
11-11-2007, 03:56 AM   #15
and
Veteran Member




Join Date: Mar 2007
Photos: Gallery
Posts: 2,471
Portraits with prime, I am not sure if I agree, sure the best portrait lenses are normally the 85mm's that have been developed for portraiture, the FA 85 is the best lens I know for this. But it depends if you are shooting natural light or not. I know of a lot of very good amateurs and professionals who use zooms for portraits, either 24-104 or most common 70-200 f2.8. I have seen several instructional videos on portrature from seasoned pros and none of them used primes. The reason is that they use lighting and the ultra fast aperture of the primes cease to be a point, also the lens is stopped down normally to at least f4, typically f5.6-f8 and just about all lenses are good at that setting.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
50mm, k-mount, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Looking for my first 50mm prime martymcfly83 Troubleshooting and Beginner Help 16 10-15-2009 05:09 PM
Whats A Better Fast Prime? The Sigma 50mm Or Pentax FA 50MM? Or Another Option? Christopher M.W.T Pentax SLR Lens Discussion 20 10-01-2009 08:02 AM
Please help me identify this 50mm prime CWyatt Pentax SLR Lens Discussion 5 08-24-2009 09:21 PM
Best 50mm prime for K20D? iht Troubleshooting and Beginner Help 30 05-19-2009 04:42 AM
Old Pentax 50mm Prime PentaxDan Pentax SLR Lens Discussion 4 10-03-2006 08:39 PM



All times are GMT -7. The time now is 07:36 PM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top