alf_beharie

I once made a 5x teleconverter to fit onto the front of a 10x zoom (38-380mm equivalent) Olympus C-730 and later the C-750 Ultrazoom digital cameras.

It was made from one front element and conical housing from a pair of 10x50 binoculars and two telescoping aluminium tubes, satin black on the outside and matt black inside...Got some good shots of David Blaine in his hanging glass box with it.

Then I got my DSLR and I have carried on modding gear as required.

I have converted a C/Y mount Vivitar 35-200mm f3-f4.5 macro to M42 mount, a Minolta Rokkor 58mm f1.4 to SA mount, I have made a Mamiya 645-SA adapter from an number 1 M645 extension ring (So I can use all M645 lenses on my DSLR), and AFAIAA I was the first person the in the world to do it:

http://sigmasd10.fotopic.net/p17717695.html

and I am soon to convert two ultra sharp Carl Zeiss lenses to either M42 or SA mount, plus I have modded a Pentax K mount lens too.

I have commercially available P6-M42 adapter so I did'nt have to make one but if Hassleblad lenses were'nt so damn expensive I'd like to make a Hasselblad-SA adapter too!

I have also stipped several lenses for parts and repaired others.

My "crowning achievment" though, IMO, was converting a pin-sharp, fixed-focus, flat-field Taylor-Hobson 12" (305mm) f4 aerial recconaisance lens to M42 mount whilst allowing it to focus too...I used the barrel from a Mirage 135mm f2.8, I shortened it with a lathe, removed the front barrel, made a barrel to T-H rear thread adapter from a 77mm Cokin filter adapter fitted to a 77-67mm adapter ring via another another custom made aluminium washer and several countersunk screws, plus a bit more machining.

I also made a revolving tripod mounting collar for it from grey uPVC and special PVC adhesive:

http://sigmasd10.fotopic.net/p30290787.html

Regards

Alf Beharie.

Looks like a smear of cleaning fluid residue across your sensor?...Did you "wet" clean your sensor last time you cleaned it?

I never recommend using fluids to clean a sensor, IMO its better to simply use a soft lens brush to dry brush across the sensor.

Regards

Alf.

Nick is the Taylor Hobson 14" f5.6 still available?

Alf.

Due to extremely stiff competition D-shell no longer manufactures any adapters and has'nt done so for about 6 months now.

Another Japanese company, JTAT, now manufactures clones of D-shells CSM422 M42-SA adapter and for the same price as the D-shell adapter.

However JTAT also manufactures other adapters and accessories for the SA mount that D-shell did not:

1) A very well made Nikon F - SA adapter:

http://www.jtat.com/sd/sd_main/SD_Nikon.html

2) A pinhole adapter (To be used in conjuction with their M42-SA adapter):

http://www.jtat.com/sd/sd_main/SD_Pinhole.html

3) An M42 depth guage (To check how far the rear element of an M42 lens extends rearwards when focussing to infinity):

http://www.jtat.com/sd/sd_main/SD_Depth.html

The other reason D-shell decided to shut-up-shop was very stiff competition from Poland, and the Aluminium Polish made adapter is still available new for under $40 on ebay.

The latest news is that a Brass, possibly chrome plated, polish made adapter is being planned, putting in on parr with the quality of the JTAT adapter but for less that half the price.

Alf Beharie.

Not from my experience with the 50mm f1.4, which was the softest lens I have ever used when WO...Unusably soft in fact, like trying to shoot through glass smeared in vaseline!...Strangely though it was sharpest at f16!

Needless to say I returned it ASAP and bought the much superior Pentacon 50mm f1.8 instead...Yes, I said superior!

As the Super Tak cost me over �40 and the Pentacon was a mere �6 the sharp results I got with the Pentacon were a very pleasant supprise.

However I have just found a slightly better lens, the Meyer-Optik Oreston 50mm f1.8 which is better than the Pentcacon in two ways, it has much better contrast and no colour cast at all (I occasionaly had a magenta colour cast problem with the Pentacon).

Thats not to say the Oreston is perfect as unlike the Pentacon, it shows edge distortion from WO-f4 (noticable at WO and at f2.8 but almost gone at f4), whilst remaining sharp in the center of the frame.

I have just tested a CZJ Tessar 50mm f2.8 as well and the Meyer is again the better lens.

As the Meyer only cost me �5, out of a "junk bin" at the recent Focus on imaging show in Birmingham, I am again very pleasently supprised!

Regards

DSG

Anything 50mm or over fitted to a macro bellows does the job nicely.

M42 lenses and bellows are cheap as chips and can work supprisingly well.

Here is an extreme close up of a Bees eye taken with a Pentacon 50mm f1.8, fitted to a cheapo Russian made M42 bellows:

http://sigmasd10.fotopic.net/p18228845.html

(click on the pic to see it full size)

The lens cost �6, the bellows cost about �10 and the Bee cost nothing!

Regards

Alf.

I recently got one of these cheap off ebay and after a thorough testing it seems to be a very good lens.

I also compared it to my Sirius 28mm f2.8 macro, and the CZJ is better.

This is why I cant understand the comments at the top of this thread:

"But yes, the 29mm f2.8 was a dog;"

...Not my conclusion at all!

But I am also confused as to is manufacture...Someone told me thats is actually a Pentacon lens, re-badged as CZJ strictly for sale to the UK market...Is this true?

I know Pentacon also did a 29mm f2.8 lens but it does not automatically follow that they are one and the same lens.

For instance many say that the Pentacon 50mm f1.8 is the same lens as the Meyer-Oreston 50mm f1.8 but my testing has shown them to be as different optically as they are mechanically...Different lenses in fact.

The Pentacon has lower contrast than the Meyer and the contrast is reduced further as you stop down, but its virually constant across the range with the Meyer.

The Pentacon also has a pronounced magenta colour cast which gets worse when stopped down to f5.6 or more but the Meyer has a neutral colour cast, across the range.

WO-5.6 the Meyer has some edge distortion which is absent in the Pentacon.

The Meyer is also better built than the Pentacon.

Sharpness wise, theres virtually nothing in it, except that the Meyers extra contrast makes it appear sharper.

I have also just recieved a CZJ Tessar 50mm f2.8 and I have compared it to the Meyer...The Meyer is a much better lens but I'm still hoping that the Tessar may prove usefull for macro work.

Regards

Alf.

Daves post pretty much confirmed what I have been arguing about on the other forum, but I might as well have been p!ssing into the wind on there as noone was taking any notice...They all argued that the opposite was the case.

Thanks Dave!

Alf.

I know DOF has nothing to do with the size of a lenses image circle

as I use several Mamiya 645 lenses on my APS sized sensor DSLR and

they have the exactly same DOF as 35mm format lenses on my camera as

long as the FL is the same.

From my experience of using small sensor digital cameras and larger

APS sized digital cameras it seems very clear that the DOF gets

shallower as the format/sensor size increases.

For instance its very difficult to get a shallow DOF shot when using

a very small sensor "P&S" camera but its much easier when using APS

sized sensor cameras.

This implies that providing the FL is different in each case to keep

the same AOV that MF will have a shallower DOF than 35mm FF and LF

will have an even shallower DOF than MF....Is this really the case?

There is an argument raging on another forum about this very topic

and any light you can shed on this would be very appreciated.

Thanks

Alf.

"Most lenses for 35mm cameras stop at F16, but a few go to f22 and even f32."

The Sigma 50mm f2.8 EX macro and the Sigma 105mm f2.8 EX macro, both go to f45.

Regards

Alf.

..Theres nothing wrong with f8...In fact I seldome shoot at anything wider than f5.6 and I mostly shoot at f8 or f11.

The reason I do has far less to do with DOF considerations than it does with getting maximum sharpness and reducing CA to as near to zero as possible.

Regards

Alf.

I currently have the Mamiya 80mm f2.8 N, which I'm very happy with,

but recently I have seen a later Mamiya 80mm f1.9 and I would like to

know how the later f1.9 version compares with the earlier f2.8

version?

...Is the f1.9 a sharper lens or about the same?

...Does the f1.9 version have better contrast than the f2.8?

...Is the extra stop usable, or is the f1.9 very soft wide open?

Thanks in advance

Alf.

Hi Stacey

Did you decide what camera to get in the end or are you still having trouble making your mind up?

Like me, I am sure it was the fantastic image quality that has attracted you to the SD10 but I understand your caution as there is so much mis-information about the SD10 put around often by those that have never even used the camera!

The SD10 was recently compared to the Canon 20D by some photographers who own both and it was found that the SD10 is a match for the 20D in resolution ie It is equivalent to an 8mp Bayer senored DSLR.

But mega pixels dont tell the whole story...

The SD10 is virtually immune to moire, it has greater colour depth, greater sharpness and greater dynamic range than any available Bayer sensored camera...It is indeed a pro quality camera.

Thats not all though, as recently the SD10 has been reduced in price, currently making it the cheapest pro quality DSLR on the market!

...Is is available with the 18-50mm DC kit lens for less than ?450 online, under half the price of the 20D!

BTW, you wanted to know how The SD10 can handle enlargements?

Well, it can produce much larger prints than you probably think it can...

AO size is easy:

http://forums.dpreview.com/forums/read.asp?forum=1027&message=7182672

2A (twice the size of A0)is also no problem:

http://www.pbase.com/sigmasd9/image/42557324/original (check out the tiny hands holding the print!)

And some Sigma SD users have even had their shots used on giant avertising billboards!

Oh, and one more thing, contary to common mis-information Sigma users DO NOT only have to use Sigma lenses. If you dont mind using manual focus lenses, the world is your oyster, so to speak:

Canon EF lenses can be easily modified to fit the SA mount as the SA mount is s clone of the EF mount, only smaller. There are many Sigma users now using Canon lenses such as the 50mm f1.4, with full AF and auto aperture.

Nikon lenses can fit via the CSN1 Nikon-SA adapter, available by special order from: www.d-shell.net. (manual focus and stop down)

Pentax K mount lenses fit straight on if you remove the auto aperture lever and plastic bezel.(manual focus and stop down)

Mamiya 645 medium format lenses fit and work perfectly via my DSGM-1 M645-SA adapter.

Nearly all M42 screw mount lenses fit and work perfectly too, via the CSM422 SA-M42 adapter, available from: www.d-shell.net

...In fact I dont use any Sigma lenses on my SD10 at all these days!

In case your wondering what some of these manual focus lenses are capable of in use, here is an example image I took with a Mamaya 645 80mm f2.8 N (Cost me just ?59!):

http://sigmasd10.fotopic.net/p11809176.html

Regards

Alf Beharie.

There are several photographers that use both the SD10 and Canon 20D.

They have compared the two side by side and their conclusions were unanimously, that the SD10 matches the 20D for resolution.

ie The SD10 is actually equivalent to an 8mp bayer sensor, not a 6mp one.

That is not the end of the story though as while the SD10 matches the 20D for resolution it beats the 20D in several other ways, namely:

Dynamic range, colour depth and saturation, an almost total immunity to image moire, autofocus accuracy (though its usually slower than the 20D's AF)and it has a unique ability only found in one other DSLR, the SD9, the ablity to capture detail right down to a single pixel...Known as "Single pixel resolution".

With its combined "IR filter/dust protector" removed by simply undoing a single screw, it becomes the most sensitive IR digital camera in the world....In fact some Pro's have bought SD10's just for IR photography.

Contrary to popular mis-conceptions SD10 users do not have to use Sigma lenses. Canon EF and Sigma lenses are the only ones that can offer AF but for those users who dont mind using Manual-Focus lenses, the world is their oyster, so to speak.

Apart from Sigma lenses, SD10 users can also use:

M42 lenses via the CSM422 M42-SA adapter (Available from www.d-shell.net)

or one of the Polish or Chinese clones that often pop up on ebay.

M39 lenses via an M39-M42 adapter ring + the CSM422 or similar.

Nikon lenses via the CSN1 adapter (Only available by special arrangement with Saturo San at www.d-shell.net).

Mamiya 645 medium format lenses via the DSGM1 adapter (Ask me for details as I am the one who makes them).

Pentax K mount lenses (With the auto aperture lever removed or cut flush with the base of the lens and the "outcrop" cut off the plastic bezel).

Canon EF lenses coverted to SA mount work very well with the SD10, with full AF and metering.

This is possible because the SA mount is a clone of the EF mount, just smaller, and it has identical electrical connections.

The Canon 50mm f1.4 was found to equal or perhaps even a tad sharper than Sigmas 50mm EX Macro, one of the sharpest lenses made anywhere in the world. Canon EF lenses also have differnt colour responses to Sigma lenses, probably due to the use of different coatings and they tend to shift the colour balance towards the red or blue channels.

(Which can be an advantage for some situations)

I dont use any Sigma lenses at all with my SD10 and I prefer to use M645 and M42 mount lenses.

Regards

Alf.

Steve Strawn wrote, (jul 10, 2003; 04:28 p.m.)

"I think a big part of the 10D's popularity is that it will use lenses built by Canon, Sigma, Tokina, Tamron, Phoenix, Quantarray, Vivitar, and on and on."

So do the SD9 and SD10!

"If you have the Sigma SD-9, you use Sigma lenses."

Not true!...I dont use ANY Sigma lenses on my SD10!

I use Mamiya 645 medium-format lenses and M42 lenses.

"Some folks like them, some don't, but with the SD-9, they're the best you're ever going to get."

No they are not!...My M645 lenses are as good if not better than any comparable lens Sigma makes.

"Oh, and the 10D is one hell of a good camera."

Perhaps it is compared to a P&S but its been proved time and time again its not a patch on the SD9 or SD10.

Regards

DSG

Hi Andrew

Satoru San at www.d-shell.net has already made a working Nikon-SA adapter, he has called the "CSN-1", but it is too expensive for him to produce it in Japan.

He was looking for a business partner that could fund the production of it overseas.

Here is a picture showing an SA7 fitted with a Nikkor lens and the CSN-1 adapters are shown below the camera body (The two larger rings sitting on top of the CSM422 SA-M42 adapter):

http://www.d-shell.net/pic/IMG_2245.jpg

If you want more details you can email him, but I warn you his grasp of English is probably a lot worse than your grasp of Japanese!...So its best to keep it simple: sarva10@desna-ua.com

As for myself, I use Mamiya 645 medium format lenses on my SD10, via the "DSGM-1" M645-SA adapter, I engineered myself, and I also use several M42 mount lenses via a CSM422 SA-M42 adapter. In fact I dont use any SA mount lenses at all these days!

Regards

Alf.

Regards

DSG

Hi all

I just came across this thread and read it with interest.

I was supprised by the number of people here that did not know about this problem.

You will find this has long been known to users of 35mm format Pentax Super-Takumars.

The main culprit in this regard is the early eight element 50mm f1.4 Super Tak, which I used to own myself and has Radioactive Thorium glass elements.

I only had mine for about a week and got rid of it quick so hopefully I did'nt suffer too much damage to my DNA!

Actually radiation was'nt the main reason why I got shot of it quick, the main reason was it was totally useless WO so it could not fufill the purpose I bought for in the first place,..as a fast lens.

The later 7 element 50mm f1.4 Super Tak was apparently able to dispense with the need to use radiactive elements so that particular lens should be ok?

However, trying to tell if its the new or the old model BEFORE you buy one is the hard part!

Anyway I noticed a few users here asked how to cure the yellowing of the Radiactive Thorium glass elements...its actually very easy.

Buy yourself a UV lamp and place it in a housing large enough to hold the bulb and the lens. "Bathe" the lens in UV like this for about 1 week continuously and this should cure the yellowing.

Now I wonder if my Taylor-Hobson 12" f4 is safe?

Regards

Alf

Thanks for getting back to me so promptly.

When researching for more info on Vinten cameras I did a Yahoo search and I came across this thread. I also saw a site going into detail on the F95 predecessors going right back to WW1.

I was very interested to see that they sometimes used 36" lenses on the early reccy cameras, back in the 1920's. I dont know how this lens with its ancient design, and lack of coatings would perform these days compared to modern lenses but I would love to give that one a go, just for its 914.4mm focal length alone! It should be awesome for bird photography. I wonder if there are any still around?

Maybe a few still exist and are being held by collectors?

Regards

Alf

Hi Dan

I have just joined the Photo.net forum and I see you

seem to know lots about the Taylor Hobson aerial

reconnaisance lenses.

I bought a TH 12" f4 from ebay for use on my Sigma

SD10 DSLR. It cost me ?36.

Here is a photo of the lens:

http://sigmasd10.fotopic.net/p14347305.html

I had to make a focus/mount adapter for it from a

shortened barrel from an old Mirage 135mm f2.8 M42

lens and a 77mm Cokin P filter ring screwed to a Hoya

77-67mm step down ring.

This was then fitted to the lens via its rear internal

77mm "filter thread".

Here is a photo of the finished adapter:

http://sigmasd10.fotopic.net/p14347309.html

And here it is fitted to the lens:

http://sigmasd10.fotopic.net/p14347307.html

I also made a rotating collar tripod mount out of a

section of PVC tube. Here it is fitted to the lens:

http://sigmasd10.fotopic.net/p14347311.html

In use on my SD10 this lens is very sharp and has very

well controlled CA. The bokeh is not as nice as with

a non-flat-field lens but the 16 point out of focus

highlights look beautifull!

Here is an example of its sharpness:

http://sigmasd10.fotopic.net/p14510383.html

(Taken from 30-40 feet away from the Stag!)

And here is an example of the lovely OOF highlights:

http://sigmasd10.fotopic.net/p14509084.html

What I would like to know is what camera this lens was

likely to have been used on and which aircraft was it

usually fitted to?

I know they could be fitted to Vinten f95 cameras and

the Agiflites but I suppose the 12" was used for high

altitude reccy work?

Look forward to your reply

Many thanks

Alf Beharie