Why bother?


Horst

Link Posted 20/07/2014 - 13:40
Hi , I am back after 3 murders in the deadliest county of England.

I have come to the conclusion, that everyone has some positive input and thinking about it, there are for and against all the arguments brought by all the forum members on this topic.

I'll have a nice sip of Courvoisier Cognac and then go to bed to cuddle up to my wife. It is freezing outside . Only about plus 10deg C..
I wish summer was back.

Regards, Horst

PIRATE

Link Posted 21/07/2014 - 00:59
andrewk wrote:
McGregNi wrote:
The higher number of mp is only one aspect of the IQ equation. Your FF owing friend can content himself that he doesn't need that massive 500mm monster after all!

My FF friend cannot afford the 500mm f/4 - but it is exactly what two lecturers at our club recently (both pro photographers - one on sports and the other on wildlife) bought so that they could get the best image possible quality. Apparently, most sports and wildlife photographers do that too - that's why you see all those dustbin lid size lenses at football matches.

Andrew

Ahoy!

Well I bought copy #10 of the Sigma AF 100-300mm F4 EX DG (IF) APO for £400.00 (I have bought them cheaper) which without doubt is THE best tele-zoom in that fixed aperture/focal range I've ever had the pleasure of owning and using. Although the IQ isn't quite to prime standards, it's darned close enough, and with the matching Sigma 1.4x TC, IQ is still retained due to the miniscule gap between the rear lenses element and the TC (it's internal focus (IF) so there's not moving parts other than the zoom and focus rings). Shame Sigma discontinued it (I'm sure someone was smoking something illegal when they made that decision), but instead of releasing the useless AF 120-400mm OS EX DG HSM to replace it, though had they upgraded it to include OS and one or two lesser features, it would've been the lens of choice for almost everyone, but for some unknown reason, used K-Mount versions are still being sold for almost original retail money I just don't get it!

What;s my point? APS-C users get the meat of the lens (not that there's any loss of IQ on full frame), plus add in the crop factor, and as with any FF lens on FF bodies, you have tons of cropping power. Maybe one day, Pentax will finally release FF bodies which will then be able to utilise the full capability of FF lenses, and maybe when Hell freezes over, the prices for K-Mount optics whether new or used will fall to real world prices.
fluidr : Airplane-Pictues : redbubble

Link Posted 22/07/2014 - 05:45
Horst wrote:

What I don't understand is why the reference to the 35mm is given on a lens which is specifically designed for APS-C.

Why would anyone give a hoot what the lens would be on 35mm if it is and can only be used on APS-C?

I might give a hoot if someone can kindly answer this question for me. Back in the golden days I was taught that the best lens for portraiture work on 35mm film was the 135mm focal length. This was because it avoided the image distortion created by some shorter lenses and provided just about the right distance between the sitter and photograher so you could get some good synergy going. I think there were were other advantages like the cost of glass but I can't remember them, it was a long time ago.

I believe that if I use a 135mm focal length lens on my APS-C sensor for taking portraits, I'll be standing well back from the sitter and may well have to use a megahorn to communicate with them (not good for interaction). However with a 90mm lens designed specifically for APS-C, I am thinking that I'll be the same distance from the sitter as if I were using a 135mm lens on a 35mm camera, but will I get the distortion like long noses and giant hands that you can get with some shorter lenses?

So, if I want to get a 'prime' lens for primarily portrait work what length lens do i go for, the old 135mm, or its APS-C equivalent which I guess is about a 90mm lens? Is it the focal length that makes a difference with the distortion issue? I tried using an old 50mm prime for some portraits thinking that works out at 75mm in APS-C. The results were not good. What do the people recommend?

It's the things like this that make me give a hoot. Hope this makes sense.
As for me, all I know is that I know nothing.

tyronet2000

Link Posted 22/07/2014 - 07:33
I think the 17-70mm is a good general purpose lens for portraits although it's not my favourite subject Your ideas on communicating with the model made me smile with the picture it generated in my mind
Regards
Stan

PPG

johnriley

Link Posted 22/07/2014 - 07:46
To answer Lu, let's take film first. I'd have used about 100mm for portraits, so now I'd use about 70mm for the same effect. For those who would have used an 85mm (the classic portrait lens for film) then the 55mm f/1.4 is the current equivalent.

As perspective depends solely on your distance from the subject, if you want to emulate what you saw with your 135mm lens, then use 90mm now.
Best regards, John

Horst

Link Posted 22/07/2014 - 13:05
John wrote:

Quote:
To answer Lu, let's take film first. I'd have used about 100mm for portraits, so now I'd use about 70mm for the same effect. For those who would have used an 85mm (the classic portrait lens for film) then the 55mm f/1.4 is the current equivalent.

As perspective depends solely on your distance from the subject, if you want to emulate what you saw with your 135mm lens, then use 90mm now.

Wow, why do it the complicated way.

If you used a 100mm lens with your film camera, why not use an other 100mm lens. one which is marked 100mm, because it is not usable for film and because it is specially made for APS-C.

Why use all the mathematics if you can do it by marking the APS-C only lenses with the focal length it really uses?

Why bother worrying about all the old and unusable markings, when you can have the new ones on the lens and don't stress your grey little cells.

If you made your portraits with a 70mm lens before, Just get a new APS-C only lens. One which is now also marked 70mm but is useless for Film or FF.

Regards, Horst

tyronet2000

Link Posted 22/07/2014 - 13:22
Quote:
If you made your portraits with a 70mm lens before, Just get a new APS-C only lens. One which is now also marked 70mm but is useless for Film or FF.

Er, I thought I was Are you trying to tell me something ?
Regards
Stan

PPG

Horst

Link Posted 22/07/2014 - 13:25
Hi Stan, I should have written :

If you made your portraits with a 70mm lens before, Just get a new APS-C only lens. One which now should be marked 75mm but was marked 50mm and is useless for Film or FF.
Regards, Horst
Last Edited by Horst on 22/07/2014 - 13:27

Aero

Link Posted 22/07/2014 - 13:39
Horst wrote:

If you used a 100mm lens with your film camera, why not use an other 100mm lens. one which is marked 100mm, because it is not usable for film and because it is specially made for APS-C.

The problem with this is that you'll have to stand farther back if you want the image to occupy the same amount of the frame because the angle of view will be narrower. And, as John says, this will change the perspective. It may not make a lot of difference in practice but there will be a subtle change in the look of the portrait.

Al

petrochemist

Link Posted 23/07/2014 - 20:02
As John mentioned it's the distance from the subject that effects the distortion. With APSC you'll want a wider lens but there's so much ability to crop these days it needn't be a 70mm a 50mm cropped to the same proportions will be fine, as long as you keep the distance about the same.

FWIW I think the original 135mm guideline was partially because 85 or 90mm lenses would have been fairly rare but 135mm were one of the top 3 focal lengths used.
Mike
.
Pentax:K5ii, K7, K100D, DA18-55, DA10-17, DA55-300, DA50-200, F100-300, F50, DA35 AL, 4* M50, 2* M135, Helicoid extension, Tak 300 f4 (& 6 film bodies)
3rd Party: Bigmos (Sigma 150-500mm OS HSM),2* 28mm, 100mm macro, 28-200 zoom, 35-80 zoom, 80-200 zoom, 80-210 zoom, 300mm M42, 600 mirror, 1000-4000 scope, 50mm M42, enlarger lenses, Sony & micro 4/3 cameras with various PK mounts, Zenit E...
Far to many tele-converters, adapters, project parts & extension tubes etc.

.[size=11:].FlickrWPFPanoramio

johnriley

Link Posted 23/07/2014 - 23:21
135mm arose because it was the longest length that could be accurately focused using a Leica rangefinder camera. SLR viewfinders are more accurate with longer lenses than this.

I always felt it was too long for portraits.
Best regards, John

Link Posted 25/07/2014 - 10:06
Aero wrote:
Horst wrote:

If you used a 100mm lens with your film camera, why not use an other 100mm lens. one which is marked 100mm, because it is not usable for film and because it is specially made for APS-C.

The problem with this is that you'll have to stand farther back if you want the image to occupy the same amount of the frame because the angle of view will be narrower. And, as John says, this will change the perspective. It may not make a lot of difference in practice but there will be a subtle change in the look of the portrait.

Al

So what focal length in old glass (primes preferred) do you guys think is best for portaits on an APS-C sensor. I can't justify to my self or the boss the cost of newer Pentax glass. She'd rather I spent my money on her own priorities.
As for me, all I know is that I know nothing.

johnriley

Link Posted 25/07/2014 - 10:13
Old or new glass makes no difference to what focal length you choose.
Best regards, John

McGregNi

Link Posted 25/07/2014 - 10:53
I love my 135mm prime for Portraits. Sure, I'm standing back a bit, but the perspective is beautiful as is the oof background at f2.8 or f4.0
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver

Link Posted 25/07/2014 - 11:54
Cheers McGregNi, I reckon there must be loads of cheap 135s out there kicking about and would probably settle for one of those.

Come on John, I value your opinion, what length would you go for as a portrait lens.
As for me, all I know is that I know nothing.
Add a Comment
You must be registered or logged-in to comment.