Visit MPB Visit MPB Visit MPB

The Sub £50 Lens Guide

johnriley
Posted 03/07/2010 - 09:39 Link
This isn't really a fair comparison. The 50mm f1.4 does not have as flat a field as the 50mm f1.7 and is not suitable for close up work.
Best regards, John
George Lazarette
Posted 03/07/2010 - 10:20 Link
It would be more interesting to compare the 1.7 with one of the 50mm macros. I suspect there wouldn't be a lot in it.

Also, it would be interesting to compare at 5.6 and 11 as well. 8 isn't always a lens's best aperture, and for macro I would usually tend to shoot at 11 anyway.

G
Keywords: Charming, polite, and generally agreeable.
johnriley
Posted 03/07/2010 - 11:20 Link
We end up doing a full lens test before we're able to make any firm judgements.

The alternative is to use the lenses in the way we would normally use them and form a judgement based on that. If the photography involved was, for example, document copying, then the macro lens would be the obvious choice from the start.
Best regards, John
Algernon
Posted 03/07/2010 - 11:26 Link
johnriley wrote:
This isn't really a fair comparison. The 50mm f1.4 does not have as flat a field as the 50mm f1.7 and is not suitable for close up work.

This is only the centre John and at this level of detail any OOF can be clearly seen. In fact the edges of the f/1.4 were still in focus.

I actually started this test to check my 300mm lenses at 20x = 6m
It still seemed OK with the 50mm's at 1.25M (25x) which this is. I want to test some 2X converters, but will have to do it outside to get back 12M

Normal accepted distance for resolution testing is 40x, but I haven't got a room big enough for the 300m at 40x (12M)

Most lenses will behave differently at about 30M anyway so any tests are really just a snapshot at the test distance.

Regarding George's question Macro lenses are sharper up to about f/8 f/11 when it becomes difficult to see any difference. Most lenses at f/8 look about the same.

The F 1.7 was sharper than the f/1.4 up to f/8
The A 1.7 was almost identical to the F 1.7 apart from at f/5.6 where it was sharper.

The A 1.4 was almost equal to the F 1.7 and the M 1.7 was only just behind them.
Half Man... Half Pentax ... Half Cucumber

Pentax K-1 + K-5 and some other stuff

Algi
Edited by Algernon: 03/07/2010 - 11:27
Algernon
Posted 03/07/2010 - 13:27 Link
Here's one from last January that's a bit unfair on the Kit-Lens Mk2 it was at 28mm f/5.6 (wide open) and the two 28mm f/2.8 lenses were at f/8.

The Pentax-A 28mm f/2.8 came out best but from other tests the Kit Lens is as good if not better.

28mm's Kit lens at f/5.6 - Image by Vivitar A at f/8 - Pentax A f/2.8 at f/8

Comment Image



Test Distance 700mm
Half Man... Half Pentax ... Half Cucumber

Pentax K-1 + K-5 and some other stuff

Algi
Edited by Algernon: 03/07/2010 - 13:34
nigelxk
Posted 04/07/2010 - 13:09 Link
the bank note idea sounds good,but ironically i changed my last £10notes to euros last week,so my options are now £20,£50,(all new ones by look of them.any idea if these are as good as the dickens tenner,or do i need to get a dickens tenner from my girlfriends bank.(got the queen side of the twenty up at mo,but again wondering which part of note to pay most attention to (like the rigging example),cheers.nigelxk.
Algernon
Posted 04/07/2010 - 14:28 Link
nigelxk wrote:
the bank note idea sounds good,but ironically i changed my last £10notes to euros last week,so my options are now £20,£50,(all new ones by look of them.any idea if these are as good as the dickens tenner,or do i need to get a dickens tenner from my girlfriends bank.(got the queen side of the twenty up at mo,but again wondering which part of note to pay most attention to (like the rigging example),cheers.nigelxk.

Possibly the Adam Smith side of the £20. You could try the Queens side as well although there does look an awful lot on that side inc. silver strips.

The rear of a £5 note is also OK.

I'm not sure what to look for, I've never photographed the £20
Half Man... Half Pentax ... Half Cucumber

Pentax K-1 + K-5 and some other stuff

Algi
nigelxk
Posted 04/07/2010 - 17:36 Link
i think i have moved the topic a little here,testing as oppossed to whats cheaper than £50,well thats a hard one for me as i brought camera,s with on average three lenses with them,my rule of thumb being analize lenses included,work out which one was on sale for the most money buy it now from dealers and bid that amount,of course the dealer lens may be in much better condition and overpriced in first place,but as i saw it the camera body and two other lenses were my bonus if i won.some were in only fair condition,but others mint,but what do i do with 50+ slr bodies i dont need ,pentax have a poor following in spain.so may have to come back to uk and list a load while i,m there.filled a 500 litre roof box plus the back of the car.fleabay is so addictive once you start buying.once i have got a good set up and test piece for my testing i will test everything up to maybe 200mm.my lenses beyond that i have already had a showdown with,with a shocking winner again,but i will conduct the test again searching harder for each lenses sweet spot.my test piece for this test was the beautifull towers in madrid,which are about three miles away.i will post my best shot so far ,and hopefully a better one soon.learning a little each day and enjoying it ,thanks to everyone who contributes to the forum,if we all contribute a little more we help to keep pentax alive.i remember the comodore amiga computers,they were superior(imo)to the bill gates equivalent at the time,but marketing played its part and it died a death,though i think the apples origins have a little to do with the amiga,so all was not lost.my point is,some people buy by name others read a lot then decide,i went for repayment mortgage 18 years ago because there was not one carrot dangled before me to steer me in that direction,my friend's opted for all sorts of offers and banged on about big money at end of endowment,a few even quoted that their financial advisers had told them it was the way to go,i told them all unless we had twenty five years of thriving britain ahead they would be making a mistake ,and five years on they were moaning that the banks had asked them to up thier repayments ,SO IMHO PENTAX IS A TOP BRAND THAT YOU CAN GET STARTED WITH RELATIVLY CHEAPLY(IF SOME OF THE BEST PHOTO,S HAPPEN TO HAVE BEEN TAKEN WITH OTHER NAME BRANDS ,ALL I SEE IS SOME OF THE WORLDS BEST PHOTOGRAPHERS ARE BEING LED BY MARKET FORCES,WE ALL KNOW THESE SAME PHOTOGRAPHERS CAN TAKE ACE SHOTS WHATEVER THE BRAND OF CAMERA THEY PICK UP ).
Algernon
Posted 04/07/2010 - 17:41 Link
I found a shot I did of a fiver. This is a lot closer then the test I've described and it's the full frame not a 100% crop. Not sure which lens it was but, I'd better be careful using it next time I could cut myself The engraving of Elizabeth Fry on the right (out of shot on this) would probably have been better for a test.

Comment Image


The lens could well have been a 203mm Kodak Extar from the 1950's. Kodak were a top maker then and the Ektars were their best range of lenses, considered by many to be better than German stuff.
Half Man... Half Pentax ... Half Cucumber

Pentax K-1 + K-5 and some other stuff

Algi
Edited by Algernon: 04/07/2010 - 17:42
Algernon
Posted 04/07/2010 - 17:55 Link
I don't think you've moved the topic Nigel .... some of the lenses mentioned here need testing..... Whoops!!!!
Half Man... Half Pentax ... Half Cucumber

Pentax K-1 + K-5 and some other stuff

Algi
nigelxk
Posted 04/07/2010 - 18:26 Link
i hate people who truly belive the hype,my kids in the past have said to me in the supermarket "if you buy that i,m not eating it" because it was not ,hienz,or some other well known brand.often i would chalenge them to a blindfold test to see if they could tell the brand they claimed was superior,in most instances they could not ,if they got it right,you shuffle the plates and they would then sometimes fluff it second time .my best shot of the towers has been took with a very cheap 400mm lens,my more expensive tair 3 could not beat it, admitedly only 300mm,but twice the wieght.
Edited by nigelxk: 04/07/2010 - 18:46
nigelxk
Posted 04/07/2010 - 19:01 Link
Comment Image

to get a idea of distance ,towers in distance are 52 storeys
Algernon
Posted 04/07/2010 - 19:08 Link
It would be interesting to see what 300mm and 400mm's you find as good performers. There's always an interest in lenses over 200mm. At around 25-30m lettering on burglar alarms make quite good test targets.
Half Man... Half Pentax ... Half Cucumber

Pentax K-1 + K-5 and some other stuff

Algi
Algernon
Posted 04/07/2010 - 19:16 Link
nigelxk wrote:

to get a idea of distance ,towers in distance are 52 storeys

That's a Tall story..... I don't believe you

I suppose that there's something there you could use maybe the plant on some of the roofs has lettering on it. The 52 storey towers seem to far away and will be affected by atmospheric conditions, but you are better placed to judge that.
Half Man... Half Pentax ... Half Cucumber

Pentax K-1 + K-5 and some other stuff

Algi
nigelxk
Posted 04/07/2010 - 19:17 Link
this shot is with cheap 400mm and cheap converter,can even pick out the cables on the window cleaners cranes.
Comment Image

Add Comment

To leave a comment - Log in to Pentax User or create a new account.