Tech Camera Lens Selections ?

[kuau]

I am taking the plunge, very deep.
Going with the Sinar artec with a Leaf Aptus II 7 AFi back. :buggies:

The artec I am buying is coming with the HR35mm lens, I am looking for 2 other lenses to complete my kit.
Sinar is recommending there:
SINARON DIGITAL 4.5/55MM
SINARON DIGITAL 5.6/90MM

but.. they also offer a 60mm and 135mm

I believe both the 55 and 90 they are recommending have a bigger image circle

Any thoughts?

 

[wentbackward]

Interested too, my 55 will arrive in August, image circle, plus feel that despite mostly using 150mm on 5x4 i could do with being a bit wider. The 120 macro is also quite interesting if anyone has any comments.

 

[yatlee]

I have a 55mm and going to let it go due to a recent upgrade. I sent you a PM on this.

 

[Paratom]

Steven,

I am not sure if the 55 is the newer HR version.
I think the advantage of the newer HR lenses is both improved resolution, and improved wide open performance.

If you ask me you need the 60HR

Frankly I would personally go with HR lenses as long as you consider to not allways shoot stopped down.

Some good info about different image circle T/S etc. of the lenses in the download area of Sinar website, also some in the Artec-manual on the website and also on the Rodenstock Website.

 

[Jack]

Everybody's needs and preferences for focals are different. All I can do is add my own personal two-cents. Long ago, I settled on my three favorite focal lengths for my particular brand of landscape shooting -- and the trio has not changed since LF film days. And while my own experience bore it out, it follows an even older formula:

If you look at some of Sinar's old data, or maybe it was Linhof's, they suggested an ideal trio was one lens at the diagonal of the film (sensor in our world) as your normal, another at the length of the short side of the sensor as your wide, and one at the 2x the long dimension of the sensor for your long.

So for your Leaf 7, that would be 36mm x 48mm with a diagonal of 60mm. So my advice is that the 35, 60 and 90 or 100 would be a nearly ideal set.

However, there are a few other considerations, mainly: 1) Image Circle and 2) Are you going to stick with a 36x48 sensor or are you planning on upgrading to something different in the foreseeable future? If you are planning an upgrade, your net focal requirement changes if the sensor gets physically larger, AND most importantly, your existing lenses may not cover the new format adequately. I only mention this because it may add significant cost to any planned sensor upgrade if you do not take it into consideration now.

 

[wentbackward]

Steven, apologies for jumping on your thread here, but I'm going through the same choices right now. The adapter for my view camera arrived from Japan today!!

Thanks Jack. I almost entirely use a 150mm on 5x4, occasionally longer, less often shorter. I've been trying to force myself to use a 35mm on a small format camera and slowly becoming more comfortable, but I'm really just a normal sort of shooter.

The 120mm macro seems like it might be a great choice, but I don't have a 90 for film, so that might also have a really nice dual purpose.

 

[kuau]

Jack,
I have been looking at a pdf file posted on the Sinar website,
A little confusing though, they list 4 different HR 60mm lenses, non of them are the "CEF" version which is for the artec, but whats confusing is the shift range for each 60mm lens
I assume the lens data I should be looking at is the "CPL" lens copal shutter, if thats the case then the HR60mm gives 18mm of shift though the 70mm gives 44mm of shift yet the 70 is not an HR lens rated at 50 lp/mm where as the 60HR is 60lp/mm
Using the aptus 7 back which would be a better lens to stitch with the 60, or 70mm lens?

Steven

 

[Jack]

Steven:

You want the "HR" series first. There were some older designs that are NOT HR, but rather APO Sironar -- you will note those MTF graphs are spec'd at 30 LPmm where the HR series is now spec'd at 80 LPmm. Inside that HR group, there are then S and W versions. The 60 HR is an S or Standard lens, and will give you modest movement with the Leaf 7, but will not give much movement on a full-frame 40x54 sensor. By contrast, the 70 HR is a "W" or wide lens, and it has a significantly larger image circle and will give significantly more shift than the 60. There is an earlier 70 and 90 that were called APO Sironars, but the designs were already sharp enough to carry the newer HR-W designations and from what I know, they are the same lenses.

Note here that in large format parlance, wide simply refers to having a larger than standard image circle and has nothing to do with focal length.

Here is a link to a PDF for Rodenstock lenses: http://www.rodenstock-photo.com/mediabase/original/e_Rodenstock_Digital_Lenses_3-26__8236.pdf

 

[kuau]

Jack,
I found in the Artec manual the following info,,
If I stick with there "HR" lenses my options are:
35mm HR, which I am already getting
60mm HR image circle 80 shift 12mm on a 48x36mm sensor
100mm HR Image circle 80 20/22 mm shift on a 48x36mm sensor

The non HR lenses have a larger image circle, so based are your advice,
it seems that the correct 3 lens set would be the 35mm HR, 60mm HR, and 100mm HR..

In comparison the 70mm lens has a image circle 100 and 20/25 mm shift so almost twice as much shift...

So based on this info, would you still go for the 35, 60, 100mm HR lenses and give up some shift for what I assume the trade off is better iq?

Steven

 

[Jack]

35, 60 and 100 HR-S will be fine as long as you don't expect excessive shifts and aren't planning on get a back with a larger sensor anytime soon. However, if either is the case, then it might be advised to look at lenses with larger IC's.

Re IQ on the lenses, I doubt there is any substantive IQ difference between the HR-S and HR-W lenses when using both centered.

 

[kuau]

Jack,
Thanks for all your help.
What's so ironic is sinars non HR lenses have bigger image circles so more movement and cost about
1000.00 less
Which way would you go? HR lenses with a higher 60lp/mm but a smaller image circle less movement or non hr lenses bigger image circle more movent bit rate at 50lp/mm

Steven

 

[Jack]

I would not use the older non-HR Sironars on any modern digital back. They were designed originally for scanning backs and were essentially redesigns of film lenses. The newer offerings from both Schneider and Rodenstock are far superior for today's smaller pixel-pitch, high resolution backs.

To be more clear, I will most likely be buying for my initial trio: a Rodenstock 40 HR-W, a Rodenstock 70 HR-w or Schneider 72mm Digitar, and a Schneider 120 digitar. When I add to that, it will probably be a 23.

My .02 only,

 

[kuau]

Thanks Jack.
I will take your advice.

Steven

 

[cs750]

Jack, I understand you have purchased the Arca Rm3di (not sure if you have had much time with it yet), but in light of your comments here about lens selection...what lenses did you include with the Rm3di purchase and what was your thinking in purchasing each specific lens? I presume you will be using the IQ180 Phase back with the Rmd3di and look forward to your review of the Rm3di in combination with all these elements. Oops....I see your post dealing with your lens choice after posting this post....so maybe you have already answered my enquiry. Thanks. Charles

 

[kuau]

Jack,
Sorry one more question
In general though I know there is no "rule"
How much shift do you need to do stitching?
As I mentioned the sinaron 60 HR has 12mm of shift at F4 and increase as you stop down.
Do you feel that is enough movement.

Steven

 

[jlm]

just did some fiddling around on paper with my lens sizing applied to full frame (180) and found:

a 10mm shift to left and right with a 43mm in portrait mode will cover the same width FOV as a 35mm in landscape mode (and is a bit taller). these two shifts would overlap about 12mm, which is about right

also to note, in this example, +/-10mm shift is about the same as +/-5.5 degree rotation, should you not have a shifting camera

 

[Jack]

Jack,
Sorry one more question
In general though I know there is no "rule"
How much shift do you need to do stitching?
As I mentioned the sinaron 60 HR has 12mm of shift at F4 and increase as you stop down.
Do you feel that is enough movement.

Steven

12mm of shift in each direction adds 24mm to the width of your base frame. On a 40x54 IQ180 sensor, this would render a 40 x 78 effective sensor. From there, you can do the math to determine effective focal. In the above case, the added frame width is roughly 54/78 or .69 of the base focal, so it changes the focal to roughly 70% of the 60, or effectively a 42 FoV at wider aspect ratio.

 

[kuau]

Thanks Jack for explaining it to me

 

[Jack]

You are of course welcome, but that's why we're all here!