just purchased a CV 21/f4 (LTM)

[mich8261]

got it used on another forum. I hope to have it before the weekend so I can get familiar with it before heading to Mexico the next weekend. Is a hood absolutely necessary?

I keep reading that you don't really have to focus this lens since the DOF is so deep. Is that true even at f4? Scale focus is probably quickest and most efficient way to focus this lens then, right?

 

[Tom A]

Well, Ken Reid raves about this lens on an other site on this forum. I have it in both LTM and P (m-mount) and it is indeed excellent. Even at f4 it has a nice sharp edge to it. The optical formula for the LTM and the P version is the same, so any "kudo's" afforded the P applies to the LTM too.
As for the hood, it is a small ring - extending 5-6 mm - or the larger "accessory hood" (See Cameraquest.com).
The flare is well controlled with the lens, but without a hood, the front element is "out there" and some care must be taken.
As for using it as a hyper focal length - it works well if you are shooting at f8 and beyond, but even a 21 has a limit to how far the DOF extends, particularly if you are close (0.7 -1.5 m) and at f4 and 5,6. At this distance you can see mis-focus clearly.
Only caveat with this lens and the small "ring" hood is that if you put a filter on the lens, the hood is then attached to the thread in the filter and can extend sufficiently to show up in the corners.
As an overall user 21 - it is a phenomenal piece of equipment, particularly it you consider the price!! It has less distorsion than a 21f2.8 Asph Elmarit and is remarkably even across the whole image field when it comes to sharpness. As a small, compact 21 I think its only rival today is the ZM C Biogon 21f4.5 from Zeiss - at twice the price!!
Be careful with exposures as it does cover a large field of view and if you are using a camera with a built in meter - it can often pick up a lot of bright "sky" and scramble the reading. Also in sunny climates like Mexico = avoid leaving the camera facing up while sipping that cold beer - it can burn a hole in the shutter quickly!

 

[chris00nj]

I usually used scale focus on this lens. Even at f/4, the dof is 6 feet -infiniti at 12 feet.

 

[mich8261]

thanks for all the info Tom. Sounds like a UV filter might do double duty as lens protector and shade. Also good point about RF cameras and the sun. I'll have to remember to keep it protected.

 

[Palaeoboy]

I have it in both LTM and P (m-mount) and it is indeed excellent. Even at f4 it has a nice sharp edge to it. The optical formula for the LTM and the P version is the same, so any "kudo's" afforded the P applies to the LTM too.

Im still curious why Sean Reid and others seem to believe the P version being superior optically?

 

[Tom A]

I don't know why this is the case. I have 3 different 21f4's. The original 21f4 LTM, the P mount version and the SC version for Nikon Rf. If there are any differences between them they are so minute that I cant see them! The SC version for the Nikon has a longer "throw" on it and it does allow a bit more of a precise focus, particularly in close.
There can of course be sample variations between lenses - but i know that my P lens, which is a pre-production sample (000006) is "blue-printed" assembly. Still, it is not significantly better than my LTM or SC mount version.
It could of course be that the P mount is easier to use on a M-mount and it removes the minute tolerance difference that can occur with an adapter. There could also be differences using it with film or digital and coded for the M8. At least with film, I know that it is a damned good lens anyway.

 

[Palaeoboy]

I don't know why this is the case. I have 3 different 21f4's. The original 21f4 LTM, the P mount version and the SC version for Nikon Rf. If there are any differences between them they are so minute that I cant see them! The SC version for the Nikon has a longer "throw" on it and it does allow a bit more of a precise focus, particularly in close.
There can of course be sample variations between lenses - but i know that my P lens, which is a pre-production sample (000006) is "blue-printed" assembly. Still, it is not significantly better than my LTM or SC mount version.
It could of course be that the P mount is easier to use on a M-mount and it removes the minute tolerance difference that can occur with an adapter. There could also be differences using it with film or digital and coded for the M8. At least with film, I know that it is a damned good lens anyway.

I also own the P and SC versions and cant say I have noticed any difference in image quality between them, hence why I asked in what area some noticed an improvement in image quality with the P over the original LTM version. One thing I noticed when the 21f4 was first released those that had the chrome version complained alot more of flare which seemed to be related to secondary reflections off the chrome filter ring. Ironically when you added a filter to cover the filter threads flare off the filter ring stopped. Now who says filters cause more flare? 😀. Just another possible reason to put out there but most like you are right Tom is most likely lens variation.

 

[rbiemer]

I own the LTM version and, for me, the biggest problem with the lens is not flare but keeping the horizon level. And that is certainly no fault of the lens rather it is operator error. I did find a double shoe adapter so I can use a small bubble level and the VF together. Works pretty well on a tripod, not so much hand held. An easy fix in post processing, though.
I got the lens when I first bought my Bessa R and have lately been using the lens on an L so I am learning scale and hyperfocal focusing with it. A different process than using the RF but not too difficult.
Excepting the FSU 50s, I don't think there is a better "bang for the buck" lens out there.
Rob

 

[kully]

Sean puts a lot of effort into his testing - focus bracketing, tripod, 100% crops - I doubt many of us with our caffiene, booze and nicotine filled veins shooting from our bare hands would notice the differences 🙂

My CV21/4 was not something I used often with film, but I'm using it a lot more on the M8.

 

[bobewest]

I use this lens on my leica standard. They go very well together.
This is a great lens and with the viewfinder that comes with it must make it the best buy

 

[oscroft]

I've used a 21/4 LTM for a couple of years now, and I love it - I have it almost permanently on my R4A.

I do try to be careful about flare, and I think it is probably better with the accessory hood. But I find the hood unusable as it blocks so much of the viewfinder.

 

[benkelley]

I think the argument about the P vs. LTM version was better QC–fewer 'bad samples'–optically the same.

 

[mich8261]

as I anxiously await the arrival of the lens, I have a question about the external VF. This is the first time I will use an external viewfinder; when critical elements are close, how much do I have to compensate for the different field of view?

 

[rbiemer]

Michel,
There are marks in the VF to indicate what the framing is at close distance.
Rob