gert_jan_bollen

Hi douglas,

That would be nice but I think it is for 35 mm instead of 67

Gert Jan

Hi John,

The there are two ways to drain your battery

1) Use MLU lor a long time (10 ~ 20u hours) it happends to me a couple of time that during transport in a bag the MLU switch went-off

I fixed this by glueing a plastic ring around the switch so it is laying recessed.

2) by Not swiching off the prism ( the old ones don't switch off automaically)

If you do not abuse rule 1 and two the battery last for decades.

Kind Regard Gert Jan

Hi Ahmad,

I think Pentax still works on their multicoating so through the years there is a difference even when it says SMC.

But i wondere if its is noticible in the print.

Kind regards

Gert Jan

Hi Radim,

your findings are correct.

As the manual says always take the light reading unshifted.

you can download the manual at the US pentax site.

Kind regards Gert Jan

Hi George,

Unless you want to burn 5k$ for a Goetchmann (german make)

you have to look for secondhand.

I was in the same position and my wishes were

1) halogeen bulp light

2) automatic transport

3) AF

4) good lenses

5) affortable

So it finally became a ROLLEI P66 + 150mm 2.8 (300$)

The price I had to pay in terms of qualityis a square slide, but when this taken inaccount when you take the picture it is acceptable.

But it makes me think of a Rollei 6008

Kind regards Gert Jan

forget my last message

more or les historical

0) prototyes asahi pentax 6x7 max speed 1/500 +/- 1965

1) asahi Pentax 6x7 +/- 1970 21 frames 0n 220 film

2) asahi Pentax 6x7 (MLU) +/- 1976 mirror lock up increased frame spacing 20 frames on 220 shutter curtan tropical resist.

3) Pentax 67 1988 minimal cosmetic changes

4) Pentax 67II the first redesign improved metering modes with prima and a brighter focusing screen and again 21 pictures on 220 film.

note 1 my experiance is that type 1 is running smoother then Type 2

note 2 all body's are exposed too ageing (for example the foam) a couple of years ago i replaced the foam on my type 1 the back and underneath the prisma with original foam of pentax (10 Euro's)

because it got sticky and i did not want too get this on the film or the shutter ofcourse inside the body there must be sticky foam too.

Kind regards

Gert Jan

rectification

4) Pentax 67 II Introduction MLU 1998 the thirst redesign of the 67 again 21 pictures on 220 film

Kind regards

Gert Jan

Hello Folks,

is there a optical difference between the T6-2X , Pentax 67 Rear

converter 2X or are there more (origional) 2x convertors

as far as I could figure out T means tele 6 means 6 elements and 2x

multiplication

does the Pentax 67 also have 6 elements?

and how about the gray editon?

Kind regards

Gert Jan

Hi Dan

It is a little bit odd that the rating for the corners are higher than the center. Or are the criteria different, for the center and the corners?

I'm waiting for the other tests

Kind regards Gert-Jan

Hi Martyn,

There is some Confusion about the COF

Here are mine thoughts, I'm not claiming to know the truth.

The Circle of Confusion is a measure of accepted unsharpness on the negative. Imagination a very small light spot, if it is in focus it will occupy close to no negative area, when it becomes out of focus it will be come bigger and bigger. When it reaches the diameter of 0.035 mm (Note that this is a one dimension notation)in terms of 35mm we still experience this as sharp. A small calculation shows that 40 line pairs/mm resolution gives a "feature-size" of 1/(2*40) = 0.0125 mm so only 3 times smaller in diameter as the Circle of Confusion.

In the end we are not interested in the negative but in the final print / slide!

The experience of sharpness is limited by the resolution of your Eyes!

Since the number and arrangement of sensitive elements in a human eye limit are fixed at 8 line-pairs /mm at a normal viewing distance 30 cm!?!.

This leads to a max print size of 40/8 * 36 mm 18 cm wide for 35 mm

and 40/8 * 69 = 34.5 cm wide for 6*7

With increasing print size also the viewing distance increases.

So this helps

To go short: The circle of confusion in the final print of a 35 mm film at 18 cm wide is (180 mm / 36mm ) * 0.035 = 0.175 mm

If we keep every thing the same but use 6*7 instead

we get 0.175 mm /(180/70) = 0.068mm

So the circle of confusion should be linear to the length scaling of the negative. ( because diameter is the one dimension field)

Basically I would expect that what was linear to the (negative) area so it would be 0.035mm * 4 = 0.14mm that would be true if the CoF was expressed in area (two dimensions)

If I'm right in MF 0.2mm CoF is used.

My guess is that the MF Cof was defined earlier and that it is more relaxed than for 35mm.

Kind regards

Gert Jan

Hi Allen,

I also noticed collor differences with the old super Takumar 105 mm.

The collor moved to yellow / brown and it gave a light loss of 1/3 ~ 1/2 stop. Finally i discovered that the kit (glue) in the rear group was ageing! you can examining this by looking from the rear at the diafragma blades they look brown, but when looking from the front they look black. My 150 mm from the same age was still Ok but this lens only contains free are elements.

I run a test in black and white between the old and a new lens and apart from a little light loss the both look the same in respect to contrast and sharpness.

Kind regards Gert Jan.

Hi Wim,

My one Euro cent opinion is that Pentax does not recommend to use the first and last stops.

Kind regards Gert Jan

Hi John,

With a lens attached, the chain tells the prism the aperture setting since it needs since it is lens open measurement in "auto" mode. the brightness is always the same. to keep a long story short 1)the chain is broken or the spring that keeps the chain on tension.

That Chain is only used in auto mode so manual is still OK.

The chain is delicate and the best way to work is to remove the lens before attaching the lens.

Kind regards Gert Jan

Hi Bill,

<p>

There is no technical reason why this would damage the lens in any

way!

<p>

Do not worry too much about technical stuff it is designed to be a

tool for photography! and not the otherway around

<p>

Kind regards Gert Jan

Hi Joe

<p>

I use with good results, a Metz CT45-4 with the 3mm bus + dedicated

(LX) contacts on the body, which gives TTL flash. so you do not need

the speciale grip, and you can use the flash remote from the camera.

The technology used in the P67II is the same as the LX (35 mm body

from 1980). The Metz 300 system (if my memory serves me well the

pentax adapter is Nr 372)already fully covers the P67II possibilities

(TTL flash). The Metz 3000 also works but you pay for AF features,

which is the same drawback of the Pentax AF 500 FTZ.

<p>

Hope this helps

<p>

Kind Regards Gert Jan

Hi Steve,

<p>

If you want to increase the speed of the lens, the trade off is

usually more distortion, to keep this on the same level as the 4.5

version you need to do the trick with aspheric surfaces.

The report I have read in the dutch Camera Magazine stated even less

distortion and 5,6 and 8 as best performinging apertures.

<p>

I would love to have a brighter view finder, but I already own the

4.5 and think the upgrate is too expensive.

<p>

And yes Steve I would like to have a 40 mm with AL lenses.

I gave up on the 45mm I have owned 3 of them and they all are not

sharp in the corners! maybe a re design would do.

<p>

Kind regards Gert Jan

Hi steve,

<p>

Why is the minimum focusing distance for the 400mm only 8 meters?

<p>

in the 35 mm world minimum distance of 10 times the focuspoint is common so a 50mm focusses down to 50cm.

for the same magnification on 6*7 we actually need ratio of 5!

so the 400 mm needs to focus down to 2 meters (6foot)

Is the reason mechanical or are there optical limitations.

Kind regards Gert Jan

Hi scott,

<p>

As i allready communicated by E-mail

<p>

I have the quick focus ring and it is useless!

You can turn the lens with the ring only over 30 degres than your

fingers are out of reach! second the lenses dont fit in the cases any

more when the ring s are attached

thirth it is very plasticy and will break soon when one would use it.

So i think they all are stil in good shape!

<p>

I wished I bought some film for the money instead!

<p>

Gert Jan Bollen

Hi Nigel,

Well Bob is right, a subject of 1cm will become 1cm on your negative independable of you use 35mm or 6x7, but when you want FULLFRAME you need to magnify more(2X)and this brings you back to the same focussing distance as a 50mm in 35.

kind regards GertJan

Hi Sarah,

<p>

The Pentax 6x7 first was shown at the PhotoKina (germany)in 1966 but

it took 3 years to get it in the shop.

the 1966 dit not have a 1 second setting.

the normal production model asahi Pentax 6x7 could make 21 pictures

on a 220 film.

in 1978 this model was upgraded with a mirror Lock Up facility and

the number of pictures on 220 whas reduced to 20.

someware between 1988 and 1990 the name changed to pentax 67

<p>

all data is out of the second hand.

<p>

Hope this helps a bit.

<p>

Gert Jan

Hi Randy,

<p>

I experiance this once with a Pentax (35mm) lens and I'm almost sure

it works the same with the 45/4. First you have to remove the shield

ring (the one which says Pentax SMC ....) basically you need a

special tool to get grip on this ring but with a needle you can get

grip on one of the holes (for example the dot in 4.0)when the ring is

moving you can screw it out with your fingers. Behind the shield ring

you will find 3 small srews which are probably lose.

<p>

Never ever use much force and he careful not to scratch.

Good Luck

<p>

Gert Jan

Hi Steve and Bill,

<p>

the 165LS has a speed of 4 instead of 2.8, becourse of the size of

the leaf shutter and its maximum shutterspeed to cover,I guess, so it

has noting to with the front element.

<p>

Kind regards Gert Jan

Hi there,

<p>

The same problem occured with my early '70 set. The finders and with

the camera back became sticky, after calling pentax (Pentax service

centre in Breda the netherlands) they send me new foam parts. You

need to ask for the repare department, not sales! the foam costs

about 6 dollar pro set.

1)these foam cushions have an self-adhesive back (tape)

2)whith alcohol you can remove the sticky dirt.

<p>

Good luck Gert Jan

Hi Alberto

The Waist-Level Finder wil Fit on both, since no electronic contacts are involved no problem will arise.

About the prism mechanically they will fit but electrically they will not, so no light metering possible!

Kind regards Gert Jan

Hello John,

<p>

It is easy to convert a P67 lens to the 645 or 35 mm systen

becourse the distance from the film to the lens mouth is with the P67

about +/-80mm and with 35 mm about 44mm so there is space for a

adaptor Pentax is selling those adapters. For the

Kiev/Pentacon/Ukrainian lens this space is about 72 mm so it is not

possible! unless you remove parts of back of the lens body but then

there is the risk that the back of the lens will hit the mirror!

<p>

and wat about the edge definition since the area which should be

sharp on a 6*7 negative is larger than 6*6

<p>

Conclusions: It is only possible to use lenses to convert which are

designed for a larger ar the same format.

<p>

Kind regards Gert Jan