tony_cunningham

Michael - Thanks for publishing the info. Unfortunately I cannot access the link. I don't remember seeing a web address with brackets before, but I could be wrong. Could you perhaps publish your text or at least your conclusions in this thread. It must be virtually unique and would be nice to have in the archives. Thanks ...... Tony

Pedro - When I scan my 6x7 transparancies at 3200 dpi and 100% I get around 8200 x 7300 pixels. That is about equivalent to a 60 MP camera.

 

There are a number of variables and other issues though:

 

1. Scanner quality. The higher the quality the higher the effective number of MPs. My value of 60 MPs assumes a very good scanner (expensive). With a cheap flatbed you might not even equal a 3 MP digital camera.

2. The film used will vary the result. My 60 MP assumes a high quality transparancy film. Of course you might wish to have texture (grain) visible in the final product so it could be arguable whether a coarse grain negative film actually reduces the quality.

3. A digital image (from a new camera!) is very clean and can be upsized in Photoshop or specialist software. This sometimes works quite well. A very good image taken with a good 10 MP digital camera with a good lens could probably be increased to 20 MP or even more and still look good when printed. This is not as effective with film cameras. Considering this argument you might say that a 30 MP digital camera was as good as our 60 MP Pentax 67.

4. The digital camera you are using for comparison makes a difference. I have 2 digital cameras - a 6 MP and a 13.5 MP. If I increase a very good image from my 6 MP camera (17 MB at 8 bit) to 50 MB I often still have a usable image. If I increase an image from my 13.5 MP camera to 50 MB the image is rarely usable. So size is not everything!

Sorry I had not noticed that the site I mentioned above is linked in the Luminous Landscape article.

Mark - If you go to this site (Understanding diffraction under Advanced topics) there is a nice explanation with beautiful illustrations and if you do some calculations you will see that this issue is less relevant for 6x7 than 35 mm and digital.

 

http://www.cambridgeincolour.com/tutorials.htm

 

Having said that it should be noticable at f32 and 45.

Here I am again on discontinued items unfortunately. I knew that

Velvia (ISO 50) was going to be discontinued in the summer, but it

seems that some people (Robert White again) have already run out. In

the Netherlands where I live no suppliers have heard of Velvia 100

(not 100F) and the old Velvia (ISO 50) is still available. I have

tried 30 Velvia 100F films and it does not suit my taste at all.

 

So I have to decide whether to fill my freezer with Velvia (ISO 50)

while I still can or to take a risk and order Velvia 100 from the US

or the UK. I may not have time to carry out a proper test. Steve

reviewed this film quite positively a year or so ago. How do you all

feel about it now?

 

My standard film for a while now with the P67 system has been Kodak's

E200. It really is ISO 200 and provides very neutral images. Many

Eurpoean customers prefer these to the more saturated Fuji look. It is

clearly more grainy than the Fuji films, but with 6x7 this is rarely

an issue and some people also seem to like the slight texture.

 

Nowadays I often take the same scene with both Velvia 50 and E200 and

decide later which best suits the end use. Another advantage of the

E200 is that it makes hand holding of all but the bigger tele lenses a

realistic option - I do occasionally use it with the 400 mm hand held.

The extra speed makes tripod use of the big lenses easier sometimes as

well. It can be pushed to ISO 400, but I have not tried this.

 

Up until 6 months ago I just walked into my local lab and purchased

E200 as required, but they have stopped stocking it due to lack of

demand. I have now ordered it by mail order and after nearly two

months it has still not arrived. Anyone else having this problem? I

notice the price of this film has also been increased considerably,

not that that is a big issue if it is unobtainable!

 

Tony

Douglas - I saw it two years ago (a mockup). At least they are taking the time to make sure they get it 100% right.

Yes Fernando that's correct. I was thinking about getting an RT 645, so I followed that closely.

Rod I also think you might be correct. A few things puzzled me about the announcement, but I decided to post it without comment. Firstly why would they discontinue a line of lenses (645) if they were about to make a digital camera for them? I suppose they might be developing a new lens line for this camera, but many of the 645 lenses are quite recent. Secondly why discontinue the 645 film body - it would surely be very useful for many serious photographers to have both film and digital options or even just to keep a film body for emergency backup.

 

The other puzzle was if they were to discontinue the 67 (and 645) why not make an announcement well in advance so that Pentax users would have the time to make last purchases? This might stimulate demand for a bit and make financial/marketing sense.

 

So perhaps it is the lead issue. Is this lead in the glass?

Can't say that I am very happy about posting this, but according to

Robert White (www.robertwhite.co.uk):

 

"Pentax have just announced the demise of their Medium Format camera

systems; both the 645N II and 67 II have been deleted. We have listed

the products currently available, and will remove items as they run

out. A digital SLR that will accept 645 FA lenses is due to be shown

at Photokina '06 in September, and should be released after that.

 

So if you were thinkng about purchasing a new P67 body or lens now is

the time.

This only applies to the bodies and relates to imports into Germany.

John - there is another solution. Go to www.gentles.ltd.uk and you will see devices that make use of the IR remote. You can trigger using a radio control system (I use a standared Futaba on my *istD and it works fine). The range is restricted to the range of the radio control. Alternatively you can make up a simple circuit with wire, a battery and a switch. Costs are very reasonable.

Carmen - I have scanned hundreds of images taken with this lens with various Imacon scanners and have never seen this. That CA is about as severe as I have ever seen, even using various digital body/lens combinations that are prone to this.

 

I suggest you rent/hire or borrow another 45 mm lens for a day and try a comparison.

I'm glad my 67 photos don't look like those, but how about one of the Zoerk adapters, perhaps not with a 67 lens, as a possible cause of the phenomenon?

Nicolas - my experience with the 45 mm is that one filter is the max. Even then I bought a specially thin polarizer. I only used it once though because in my experience these polarizers are useless on very wide lenses - too much variation in sky colour. Have never used a filter on my 55 mm.

 

Another trick to avoid vignetting on a wide lens is to purchase a bigger filter than you need along with adapters to fit your lenses. This works ok, but you might need to fabricate some kind of lens hood.

 

I meant screw in filters above. I have also cut down a Cokin adapter for use with my 45 mm. It is cut so that it just takes one filter and every bit of plastic except the minimum needed to hold the single filter has been cut away. Only takes a few minutes with a sharp knife or hacksaw and file. By the way you can slip filter gels in the back of the 45 mm. That should be ok if you need an ND filter.

 

I very much doubt if using filters on the 35 mm is a practical or desirable proposition.

> It's hard not to notice that two of the four above respondents have made no financial contribution to PN. How do you think they pay for all this stuff?

 

I am one of those. I tried to pay a couple of years ago, but they would not accept my money because I was not US based.

 

> Tony why don't YOU try providing another less commecial home for this excellent forum?

 

It had crossed my mind that I might make a server available at some stage if this forum needed to move, but I did not want to tread on Steve's toes. Also many forum members might like the facilities on offer here. A move back to LUSENET might be a good option.

Agree with above - Steve do you think we could find another less commecial home for this excellent forum?

I can confirm the loading problems with the older non-mlu body. I used one to back-up my P67 body up until a couple of years ago and quite often struggled to load it. Apart from that I was very fond of that body when used hand-held. I now use a second P67.

 

A related topic: I have been using a P67 for about 10 years and after a couple of years had developed my loading technique to the extent that I could manage quickly in near darkness. Just recently I have started to have loading problems with my P67. This became so severe recently that I began to wonder if the tolerances on the manufacturing of the plastic spools has changed, or perhaps the material has been changed to one with a higher expansion coefficient. This would seem unlikely though as I have experienced problems with both Kodak and Fuji films - perhaps it's just me.

Geoff - Folowing up on Peter's suggestion, I use the following technique occasionally - ideally with a tripod - but sometimes hand held. Pentax 67 body with 45 mm lens or Fuji 6x9 rangefinder with 65 mm lens. Take the picture vertically (portrait)with the subject in the top half of the frame. Then crop to 645. Followed by some Photoshop work. A Fuji 6x9 is probably cheaper than a PC lens for 35 mm.

I purchased a 173G from a German supplier 6 months ago. I suppose it is aluminum. It was very reasonably priced and is peraps a bit crude, but it is nice to use and works very well with all my cameras. I have used it with most P67 lenses up to the 400mm with no problems.

Many thanks for your responses. I have only just solved the problem by purchasing an adjustable (60-110 mm) chain wrench for removing oil filters. I removed the tripod mount to allow enough space for the chain and placed two layers of rubber sheeting over the threaded ring to protect it. It still took considerable effort to remove it. The chain penetrated the rubber and scored the surface of the ring at one point, but nothing serious.

 

I tried a hair dryer, then moved up to an electric paint stripper used carefully, but heating did not work. I did not dare use oil, although it would have been the next stage if the wrench had not worked.

This might cheer some of you up:

 

GOLDEN, CO (March 15, 2005) PENTAX Imaging Company has announced that

PENTAX Corporation will unveil the first PENTAX 645 Digital medium-

format camera at the Photo Imaging Expo (PIE) from March 17?20, 2005

in Tokyo. This latest PENTAX digital advancement will be showcased

under glass at PIE 2005.

 

The PENTAX 645 Digital camera will offer professional quality digital

image reproduction. The camera will also feature:

 

A reliable PENTAX 645 AF mount

 

Compatibility with existing smc PENTAX 645 interchangeable lenses

 

A Kodak developed extra-large CCD image sensor with 18.6 total

megapixels.

George - I think you are overselling the P67 as a studio camera. There is now only one leaf shutter lens available - the 165 mm. It is my most used lens though and my favourite of all lenses on all my cameras. The 90 LS is also available secondhand, but rarely in new condition anymore.

David - Can you explain the advantage of the Kirk plate? I have just successfully taken 100 vertical images without the slightest problem using a selection of lenses from 45mm to 400mm with an ordinary heavy tripod and an ordinary heavy ball head. I mention successfully because the model prior to the II has an excellent exposure meter and I have never felt the need to upgrade. Why would I want to carry yet more weight?

 

Considering current pricing, I would use a P67 in the field and an RB 67 in the studio. The optics are equivalent - both very good for most lenses. Warren - perhaps you should explain what eaxctly you mean by nature - you might be in the wrong department altogether!

I have a 400 mm lens (outer bayonet threaded mount) jammed on a P67

body. Any ideas? I am almost certain it is not cross threaded. How

about trying one of those vehicle oil filter removers? I don't think

they are big enough diameter to pass over the body of the lens

though. The lens is in near perfect condition, so I don't want to

damage the ring if at all possible. I mounted the lens at around

freezing and am trying to remove it at room temperature, but I have

done that many times before without problems.

Shaun - I have the Manfrotto 441. I have no idea how it relates to the one you are considering, but it has all the features you describe. It has been extensively used for 18 months in cold and hot weather without problems. It is light, very fast to set up, easy to adjust and nice in cold weather. I don't use the lateral arm often, but it has been handy a couple of times. It is a bit fiddly to remove from the standard position and I do wonder if you use it a lot whether it might cause wear.

Dave,

 

Firstly the film should be ok for the uses you propose. The NC would be better for sunny weather and the VC for dull weather.

Secondly you don't have to worry about the date. If the film was ok when you bought it and you have had it in a freezer at say -17 deg C or less, the film will be fine in 2010 or even 2015 - so you can think about it for a while longer!

 

46mm or 127 film is narrower than 120 or 220 film so, although your proposal will work mechanically I suppose the edges will curl and you will have sharpness problems. Perhaps you could make a mask? If I was you I would sell them or give them away or use them for experiments.

Tony