All Forum Comments
Comment by Anvh posted on Spanish Pentax lens prices at 13/07/2009 - 21:22
thoramay wrote:
Thanks, George. The fisheye is a puzzle. I have read a review that states it is a deffinate fisheye, yet when I try it out there is not much evidence of any distortion, just a slight drunken appearance to the lamp posts. Don't have much idea, though. Thought it might be a useful everyday lens. Have seen one advertised at over 200 dollars. Have offered £50 quid. Would that be a bargain?
This the lens right?Thanks, George. The fisheye is a puzzle. I have read a review that states it is a deffinate fisheye, yet when I try it out there is not much evidence of any distortion, just a slight drunken appearance to the lamp posts. Don't have much idea, though. Thought it might be a useful everyday lens. Have seen one advertised at over 200 dollars. Have offered £50 quid. Would that be a bargain?
more info link
Did you try it on a DSLR if so the reason you don't see much distortion "fish eye" because it was make for 35mm and not a cropped sensor.
Comment by Anvh posted on what to pay at 13/07/2009 - 20:35
sanderscapes wrote:
Optics are the same as with the MarkII from what we know so far.Greytop wrote:
I also agree with you regarding the little DA 18-55 WR. Not bad performer at all from my tests so far
If it's anything like the previous kit lenses greytop i will be excellentI also agree with you regarding the little DA 18-55 WR. Not bad performer at all from my tests so far
It's a fine link that Nathan posted about front and back focusing but it doesn't explain what effects that tolerance in the lens.
In a way the AF unit in the camera works like our eyes, it looks through the lens and confirms focus that way.
So if the Lens is out with -10 (don't know what would be out but play along) and the AF unit is out by +2, according to the read you will get -8 "focus unit" out of perfect.
What I say is that since the AF looks through the lens and simply focus the lens to +2 focus since the AF unit is out by that.
I know that the first is true in real life but none still haven't explained how it comes and why the second one isn't true.
In a way the AF unit in the camera works like our eyes, it looks through the lens and confirms focus that way.
So if the Lens is out with -10 (don't know what would be out but play along) and the AF unit is out by +2, according to the read you will get -8 "focus unit" out of perfect.
What I say is that since the AF looks through the lens and simply focus the lens to +2 focus since the AF unit is out by that.
I know that the first is true in real life but none still haven't explained how it comes and why the second one isn't true.
Comment by Anvh posted on can back focus be fixed? at 13/07/2009 - 17:49
What's the VAT rate in Spain John?
The price seem to be on the high side in Spain.
Our prices from two shops.
www.fotokonijnenberg.nl - www.kamera-express.nl
Used current rate.
1 € = 0.866111905 UK£
1 UK£ = 1.15247567 €
SMC DA 15 mm F4 LIMITED
€649,00... £563,14
SMC DA 55 mm F1.4 SDM
€499,00... £432,98
SMC D FA 100 mm F2.8 MACRO
€469,00... £406,95
SMC D FA 50 mm F2.8 MACRO
€399,00... £346,21
SMC DA 300 mm F4 ED IF SDM (star)
€999,00... £866,82
SMC DA 200 mm F2.8 ED IF SDM (star)
€799,00... £693,29
SMC DA 70 mm F2.4 LIMITED
€444,00... £385,26
SMC DA 40 mm F2.8 LIMITED
€272,00... £236,01
SMC DA 35 mm F2,8 MACRO LIMITED
€349,00... £302,83
SMC DA 21 mm F3.2 LIMITED
€469,00... £406,95
SMC DA 14 mm F2.8 ED IF
€575,00... £498,93
SMC DA 55-300 mm F4-5.8 ED
€299,00... £259,44
The price seem to be on the high side in Spain.
Our prices from two shops.
www.fotokonijnenberg.nl - www.kamera-express.nl
Used current rate.
1 € = 0.866111905 UK£
1 UK£ = 1.15247567 €
SMC DA 15 mm F4 LIMITED
€649,00... £563,14
SMC DA 55 mm F1.4 SDM
€499,00... £432,98
SMC D FA 100 mm F2.8 MACRO
€469,00... £406,95
SMC D FA 50 mm F2.8 MACRO
€399,00... £346,21
SMC DA 300 mm F4 ED IF SDM (star)
€999,00... £866,82
SMC DA 200 mm F2.8 ED IF SDM (star)
€799,00... £693,29
SMC DA 70 mm F2.4 LIMITED
€444,00... £385,26
SMC DA 40 mm F2.8 LIMITED
€272,00... £236,01
SMC DA 35 mm F2,8 MACRO LIMITED
€349,00... £302,83
SMC DA 21 mm F3.2 LIMITED
€469,00... £406,95
SMC DA 14 mm F2.8 ED IF
€575,00... £498,93
SMC DA 55-300 mm F4-5.8 ED
€299,00... £259,44
Comment by Anvh posted on Spanish Pentax lens prices at 13/07/2009 - 17:24
Bojidar Dimitrov wrote:
"SAFOX" stands for Sensor Ability Fortifying Optical Compensating System. It has gone through four revisions, with SAFOX-I being used in the SF series AF bodies, and SAFOX-IV being used in the ZX/MZ bodies. All SAFOX-type lenses are fully compatible with all SAFOX bodies. Basically, this means that the SF, Z/PZ, and ZX/MZ bodies are all compatible with all F and FA lenses.
This system works as follows. The main mirror which is semi-transparent in the middle lets a fixed amount of light pass to a small auxiliary mirror at its back. This mirror redirects the light to a light sensitive CCD-sensor which makes a decision on whether the image is in focus, and then transmits an electrical signal to the auto focus chip. This chip calculates the required amount and direction of rotation of the AF motor. The "in focus" analysis is based on phase detection. The light rays which are deflected by the auxiliary mirror are passed through an infra-red filter and then through a lens system that splits the image in two. If the image is in focus, these two images match. If the lens is focused to far, the two images have a greater distance on the CCD line, if it is focused to narrow these two images have a shorter distance then in the “zero“ position. Out of this image-, phase-shifting the computer calculates the number and direction of rotations for the auto focus motor. It is not possible to stop right now from a full speed focusing to the exact point. So the speed is reduced before the right focus point is reached. The computer of the camera subdivide the number of turns to reach the right focus point. A photo interrupter in the lens count the impulses and send it back to the camera. The camera compares the actual value with the rated value. A certain steps before the rated value is reached the speed of the auto focus motor is reduced. To the motto "Trust is good — control is better" the computer starts a control measuring.
Full read
A photo interrupter in the lens is the only part in the lens that plays a part in the autofocus sequence. Would that be the cause to all the trouble?"SAFOX" stands for Sensor Ability Fortifying Optical Compensating System. It has gone through four revisions, with SAFOX-I being used in the SF series AF bodies, and SAFOX-IV being used in the ZX/MZ bodies. All SAFOX-type lenses are fully compatible with all SAFOX bodies. Basically, this means that the SF, Z/PZ, and ZX/MZ bodies are all compatible with all F and FA lenses.
This system works as follows. The main mirror which is semi-transparent in the middle lets a fixed amount of light pass to a small auxiliary mirror at its back. This mirror redirects the light to a light sensitive CCD-sensor which makes a decision on whether the image is in focus, and then transmits an electrical signal to the auto focus chip. This chip calculates the required amount and direction of rotation of the AF motor. The "in focus" analysis is based on phase detection. The light rays which are deflected by the auxiliary mirror are passed through an infra-red filter and then through a lens system that splits the image in two. If the image is in focus, these two images match. If the lens is focused to far, the two images have a greater distance on the CCD line, if it is focused to narrow these two images have a shorter distance then in the “zero“ position. Out of this image-, phase-shifting the computer calculates the number and direction of rotations for the auto focus motor. It is not possible to stop right now from a full speed focusing to the exact point. So the speed is reduced before the right focus point is reached. The computer of the camera subdivide the number of turns to reach the right focus point. A photo interrupter in the lens count the impulses and send it back to the camera. The camera compares the actual value with the rated value. A certain steps before the rated value is reached the speed of the auto focus motor is reduced. To the motto "Trust is good — control is better" the computer starts a control measuring.
Full read
Still the AF works even with M lenses giving indication when it sees it's in focus.
And as far as I know it confirms focus right?
Comment by Anvh posted on can back focus be fixed? at 13/07/2009 - 00:06
Tolerance of what Kris, you got me totally lost there
Comment by Anvh posted on can back focus be fixed? at 12/07/2009 - 23:55
PentaxBabe wrote:
Stefan,
I agree with you entirely. Hearing everyone debating whether or not to get the K-7 makes me wonder if I should to. But like you said while it would be nice to say you had the latest camera with nice new extras and better things, I have to remind myself that I should learn how to get the most out of the camera I have now before even considering upgrading again. That said, I had to use my K200D today as the battery on my K20D was flat, I am was really surprised how quickly I have come to rely on the front and back "D rings(?)" things. I really struggled going back to just one
They are called E-dials Stefan,
I agree with you entirely. Hearing everyone debating whether or not to get the K-7 makes me wonder if I should to. But like you said while it would be nice to say you had the latest camera with nice new extras and better things, I have to remind myself that I should learn how to get the most out of the camera I have now before even considering upgrading again. That said, I had to use my K200D today as the battery on my K20D was flat, I am was really surprised how quickly I have come to rely on the front and back "D rings(?)" things. I really struggled going back to just one
The K20D is a fine camera and also the K200D and they will both give you a lot of fun for the years to come.
Many of the users that upgrade to the K-7 don't need the extras but simply want. It probable make somethings more enjoyable but I'm not at a point yet to say goodbye to my K10D.
Since you only recently got the K20D get some good lenses for it, you will get more enjoyment out of that then a new body.
Also lens prices are very stable they don't go down if not being replaced by new model and even then they hold their value very well.
Camera body is like all the other electronics outdated when it comes out and it will drop in price over the year.
Better to wait and get a lens now and save some money when the K-7 is cheaper.
Comment by Anvh posted on What would you do now at 12/07/2009 - 23:51
sanderscapes wrote:
Lenses can definately be calibrated which was an option i had at the time from sigma.But i preferred to send it to srs.
I wonder how though...Lenses can definately be calibrated which was an option i had at the time from sigma.But i preferred to send it to srs.
I can't see the lens paying any "active" part in the focusing.
The lens doesn't say if it is in focus or not it simply moves nothing more right?
The sensor for the autofocus works through the lens.
The mirror is semitransparent and a second mirror behind the big mirror reflects the "focus-beam" to the focus sensor in the camera and the camera let the lens move (SDM or screwdrive).
So how can the lens effect to focus?
Even got a pretty picture
1: silicium-diode from the exposure metering system
2: ocular
3: pentaprism
4: focusing screen
5: main mirror
6: auxiliary mirror
7: auto focus module SAFOX
Comment by Anvh posted on can back focus be fixed? at 12/07/2009 - 23:40
Nice photos Jeanette, you're getting the hang of it
I love the first one the most, the colours are so nice.
I love the first one the most, the colours are so nice.
Comment by Anvh posted on Playing with the M 200mm f4 K Again at 12/07/2009 - 22:35
Can you think of a reason why there is a price difference?