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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Image Circle Database

Matthew Duclos said:
Shawn is the inspiration behind this pic from a couple months back...
3552067921_d7b0f92b3d_o.jpg
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Haha! I love it! It needs me looking at lens with a thought bubble going up to that picture
 
Matthew,

Can you get a set of Illumina S35 lenses in to measure their image circle dimensions? When you have a chance, can you add IC info of other lenses to your database to benefit the community even more.

By the way, I have reserved a Duclos 11-16mm lens for more than three months now, when can I pay a deposit or even pay in full? When should I expect delivery?

Thanks.
 
Matthew: Thanks for this service to the community. I don't see any LOMO lenses in the mix. Do you not get them in your shop or is there some other reason the data is not in your database?

I have about 40 or so LOMO's. If you can tell me how to accurately measure the image circle, perhaps I can augment the database.

Thanks
 
Chris Parker said:
is there any lens out there that will cover the full 5K, INCLUDING the widest length.
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Zeiss Compact Primes.
RPP should cover 5K I think.
Everyone keeps asking if their lenses will cover 5K.
Im gonna wait to answer these questions until RED rolls out the actual camera.
Specs change...
 
Michael Panfeld said:
Matthew: Thanks for this service to the community. I don't see any LOMO lenses in the mix. Do you not get them in your shop or is there some other reason the data is not in your database?

I have about 40 or so LOMO's. If you can tell me how to accurately measure the image circle, perhaps I can augment the database.

Thanks
Click to expand...

This is VERY difficult because there are so many different versions of Lomos and very little way to identify them without actually seeing them.
We see Lomos here fairly often but they are just too random and scattered.
In fact I have the MONSTER LOMO sitting in our vault.
It's a 25-500mm f/3.5 that weighs about 35 lbs. lol
 
Matthew Duclos said:
This is VERY difficult because there are so many different versions of Lomos and very little way to identify them without actually seeing them.
We see Lomos here fairly often but they are just too random and scattered.
In fact I have the MONSTER LOMO sitting in our vault.
It's a 25-500mm f/3.5 that weighs about 35 lbs. lol
Click to expand...

Huh? I'm confused. They all have unique model #'s engraved on each lens (a model starts with OKC + design # + focal length + version). Its very clear how to identify them. For example:

OCK1-100-1 is a 100mm f2.3
OKC7-28-1 is a 28mm f 2.0
OKC10-28-1M is a 28mm f1.4
OKC1-300-1 is a 300mm f4.0
OKC12-35-1 is a 35mm f1.5
OKC11-35-1 is a 35mm f2.0
OKC1-50-6 is a 50mm f 2.0

All lenses within each model # should have the same size image circle. Each model is produced according to a strict Russian standard put out by GOST, the Russian Standards agency (similar to the U.S.'s SAE or ASTM standards). Are you saying that you have had two lenses of the same unique model # and that they had different image circle sizes?

Nevertheless, if you can please explain how you are measuring the image circle, I will do it myself, post it, and people can take it for what its worth.

Thanks
 
I believe I was not clear enough in my explanation.
I'm aware that each lens has a unique serial number as with every manufacturer.
My predicament is in the identification on the list.
For example, it is easy to create a section for Zeiss Super Speeds.
For Lomo lenses there is, to my knowledge, no nomenclature for the Lomo lenses other than user adopted "square front", "round front" and production date.
If I am missing something in the Lomo brand that would allow me to better identify the lenses, please help me help you.
To further illustrate my dilemma I propose an example:
If I were to list a 25mm Lomo, there isn't really any way to determine which 25mm I would be referring to in the Lomo family other than its optical properties such as aperture speed, square/round front anamorphic, etc.
 
I measure the effective image circle with a projector and a precisely marked reticle.
My measurements are relative to specific marks on the reticle.
There is usually a certain level of light loss around the edges of the image circle to which I determine a "usable" range based on my experience and measure from there.
 
Matthew Duclos said:
For Lomo lenses there is, to my knowledge, no nomenclature for the Lomo lenses other than user adopted "square front", "round front" and production date.
If I am missing something in the Lomo brand that would allow me to better identify the lenses, please help me help you.
To further illustrate my dilemma I propose an example:
If I were to list a 25mm Lomo, there isn't really any way to determine which 25mm I would be referring to in the Lomo family other than its optical properties such as aperture speed, square/round front anamorphic, etc.
Click to expand...

Sorry for the delayed response, but we had a bit of a snowstorm on the East Coast. Yes Matthew, there is a very specific nomenclature.

Unlike most cinema lens manufacturers, LOMO has a very large number of models. Indeed, I'd say that LOMO was the most prolific cinema lens manufacturer. Not necessarily in terms of the sheer number of lenses produced (although that may be true), but in terms of the number of models. LOMO lens models are not "rolled out" for all focal lengths as part of a series (e.g., Cooke S4s or Zeiss Superspeeds). Rather, each focal length has its own series of optical designs and each design usually has multiple versions and these were rolled out on an ad hoc basis over time.

I have been documenting LOMO lens models and have a list of LOMO 35mm cine primes alone that approaches 90 different lens models. That does not include the dozen+ 35mm zooms and the 10-20 anamorphic primes. And that is just 35mm cine use. There is a whole second set of primes and zoom lens models for 16mm usage.

So no, you are correct that you cannot just toss up on the list 25mm and have it make sense, any more than you can simply add Cooke 35mm and not distinguish between Cooke S4 35mm, Cooke S3, 35mm, Cooke S2 35mm, etc...

The nomenclature needs a bit of explanation. First of all, it uses the cyrillic alphabet. Some people use the characters as they are written, while some translate these using the sound that they make. For example, cinema primes have OKC imprinted on the lens. But, because a "c" in Russian is pronounced like an "s" some people identify the lens as OKS in postings online, ebay, etc. Once you get past this confusing part, the rest is pretty standard (Ha!).

In terms of the nomenclature, first note that lens model numbers are different from the lens' serial number. The serial # would appear as 8700012 (where the first two digits are the year of manufacture and the remainder is a serial number - so that would be the 12th lens of that model produced in 1987). The serial number restarts each year and for each model.

The lens model # for spherical primes is simplest to decipher and consists of several parts:

Part 1: indicator of film type (16 or 35mm). So it will have a 16 or a 35 as the first two digits with some caveats: first, lenses manufactured by EKRAN have the 35 printed while spherical prime lenses manufactured by LOMO leave this blank (anamorphic primes made by LOMO always start with 35). If the lens is intended for 16mm film, then the Part 1# always starts with 16 regardless of manufacturer.

Part 2: indicates the type of lens

OKC means spherical prime

Part 3: Optical Design

a 1 or 2 digit number that indicates the optical design. These follow a chronology so that 1 means the first (and earliest design, whereas a larger number like "12" indicates a later design). Later designs are not necessarily better.

Part 4: focal length

self-explanatory. The focal length is both preceeded and followed by a dash

Part 5: series number

there may be multiple iterations within an optical design as the Soviets were always improving and experimenting. Note that if there is an "M" at the end, this indicates a "fast" aperture. However, not all fast lenses had this additional designation.

So with this its pretty easy to decode:

OKC1-22-1 is a sperical prime made by LOMO, of the 1st optical design, of a 22mm focal length, in its first version. All OKC1-22-1's will have the same image circle. However, it may or may not have the same image circle as other 22mm LOMO spherical primes (e.g., OKC3-22-1, OKC5-22-1, or OKC6-22-1).

Zooms and anamorphic models have a similar nomenclature, except that it does not have Part 4 (i.e., the focal length) in the model#

Part 1: 35 or 16

Part 2: indicates the type of lens

OPF means spherical zoom
BAC means anamorphic prime (round front or square front - you just have to know which is which based on the design number)
HAC means anamorphic prime (old school 2-piece square front designs)

Part 3: unique design #

Part 4 - version - always 1

So 35 OPF-18-1 means a 35mm film zoom lens of the 18th design. The 18th design happens to be a 20-120mm zoom.

35BAS22-1 means a 35mm film round front anamorphic, series 22. Series 22 = 50mm focal length.

There may be multiple anamorphics and zooms of the same focal lengths, but each would have a unique design number. For example:

35 OPF-7-1 and 35 OPF-15-1 are both 25-250mm zooms.

So no, you can't just say LOMO 28mm and the image size. However, you can say OKC12-28-1 and give the image size and everybody with that model can rest assured that theirs has the same image size, but those with say a OKC4-28-1 will not expect the same image circle size.

I realize that posting LOMO image circles on your list may require either an asterisk with an explanatory note or an extra column to indicate the focal length and the model #. I'll be glad to help. Let me know. Thanks
 
Michael is completely accurate and correct in the above explanation. I would just like to add, that the same lens (ie OKC1-22-1) may be in any number of different housings. They were housed differently for different cameras, and different uses (studio versus doc/news). So you can have three completely different looking lenses that are optically identical.

Nick
 
Now, here's a curiosity.

I was reading the Cooke website, specifically about the new Panchros. They're advertised as having a maximum coverage of 30mm, which is slightly smaller than required for 5K 2:1, as I understand it.

I then looked at the page for the S4s, and they are advertised as having the same maximum coverage. Contrary to this, Matt's database shows the majority of S4s as having an image circle of more than 30mm.

Matt, can you shed any light on this discrepancy? I have no doubt that you're conducting your image circle tests properly, and yet this information is coming right off of Cooke's website. I'm just hoping that this means the Panchros (and the 5is) might actually cover some form of 5K, which would be great.
 
Ryan S said:
Now, here's a curiosity.

I was reading the Cooke website, specifically about the new Panchros. They're advertised as having a maximum coverage of 30mm, which is slightly smaller than required for 5K 2:1, as I understand it.

I then looked at the page for the S4s, and they are advertised as having the same maximum coverage. Contrary to this, Matt's database shows the majority of S4s as having an image circle of more than 30mm.

Matt, can you shed any light on this discrepancy? I have no doubt that you're conducting your image circle tests properly, and yet this information is coming right off of Cooke's website. I'm just hoping that this means the Panchros (and the 5is) might actually cover some form of 5K, which would be great.
Click to expand...

Not sure why Cooke would say that...
It may very well be a matter of opinion. They may consider 30mm the acceptable image circle.
I measured to what I considered reasonably usable in regards to light and focus falloff.
They may also want to keep things simple and not list a mere 2mm difference between some lenses and not others.
Just my guess.
 
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