Ad
Ad
Ad
Pages: [1] 2 »   Bottom of Page
Print
Author Topic: hasselblad sensor crop factor  (Read 15898 times)
Abdulrahman Aljabri
Sr. Member
****
Offline Offline

Posts: 260



WWW
« on: August 21, 2009, 10:18:18 PM »
ReplyReply

Its common to find the crop factor for smaller sensor cameras, but nothing can be found for the hasselblad medium format cameras such as the H3DII-50. Perhaps that's because crop factor can't be made to go below 1?

Assuming, however, that such factor exists, what is the H3DII-50 crop factor? Since the sensor is 36x48 and is reported to be double the size of 35mm 36x24 sensor, is the crop factor .5?

So using a 100mm lens would give an equivalent angle of view of 50mm in 35mm cameras? Shooting at f2.8 provides depth of field similar to 2.0 on 35mm cameras? Also what is the 36x48 senor known as, 70mm?


Thanks in Advance!
Logged

MY SITE: ALJABRI MEDIA PRODUCTION

Abdulrahman - and yes its a long name but has a meaning "servant of the merciful". you can also call me abdul
asf
Sr. Member
****
Offline Offline

Posts: 506


WWW
« Reply #1 on: August 21, 2009, 10:24:54 PM »
ReplyReply

go to alpa.ch and download their calculator xls file

it's free

Logged
Abdulrahman Aljabri
Sr. Member
****
Offline Offline

Posts: 260



WWW
« Reply #2 on: August 21, 2009, 10:37:01 PM »
ReplyReply

Quote from: asf
go to alpa.ch and download their calculator xls file

it's free

wow, that's a pretty sophisticated document, only thing I can't figure out how to use it yet.

Thanks for posting
Logged

MY SITE: ALJABRI MEDIA PRODUCTION

Abdulrahman - and yes its a long name but has a meaning "servant of the merciful". you can also call me abdul
Dick Roadnight
Sr. Member
****
Offline Offline

Posts: 1730


« Reply #3 on: August 22, 2009, 01:04:23 AM »
ReplyReply

Quote from: abdul10000
Its common to find the crop factor for smaller sensor cameras, but nothing can be found for the hasselblad medium format cameras such as the H3DII-50. Perhaps that's because crop factor can't be made to go below 1?

Assuming, however, that such factor exists, what is the H3DII-50 crop factor? Since the sensor is 36x48 and is reported to be double the size of 35mm 36x24 sensor, is the crop factor .5?

So using a 100mm lens would give an equivalent angle of view of 50mm in 35mm cameras? Shooting at f2.8 provides depth of field similar to 2.0 on 35mm cameras? Also what is the 36x48 senor known as, 70mm?


Thanks in Advance!
The CCD area is double 35mm, not the size, so the cropfactor would be the reciprocal of the square route of 2.  1/1.414
Logged

Hasselblad H4, Sinar P3 monorail view camera, Schneider Apo-digitar lenses
Abdulrahman Aljabri
Sr. Member
****
Offline Offline

Posts: 260



WWW
« Reply #4 on: August 22, 2009, 01:21:00 AM »
ReplyReply

Quote from: Dick Roadnight
The CCD area is double 35mm, not the size, so the cropfactor would be the reciprocal of the square route of 2.  1/1.414

=.7 correct? I found this link its very useful in calculating crop factors: http://uk.fotopunto.com/articulo-crop-fact...-calculator_128


I noticed you have the H3DII 50, what made you buy that camera over other 35mm high resolution cameras including the 5DII and D3X?


Thanks
« Last Edit: August 22, 2009, 01:21:48 AM by abdul10000 » Logged

MY SITE: ALJABRI MEDIA PRODUCTION

Abdulrahman - and yes its a long name but has a meaning "servant of the merciful". you can also call me abdul
asf
Sr. Member
****
Offline Offline

Posts: 506


WWW
« Reply #5 on: August 22, 2009, 01:24:54 AM »
ReplyReply

Oooh! Ooh! This may be even better than the triple workshop threads
Logged
01af
Sr. Member
****
Offline Offline

Posts: 294


« Reply #6 on: August 22, 2009, 10:34:24 AM »
ReplyReply

Quote from: abdul10000
Assuming, however, that such factor exists ...
Sure it does.


Quote from: abdul10000
... what is the H3DII-50 crop factor? Since the sensor is 36 48 mm ...
So the crop factor is 1.32 ... that's with respect to the frame's diagonal. So an 80 mm standard lens on the H3DII-50 will give you basically the same coverage as an 1.32 80 = 110 mm lens on a traditional Hasselblad camera.

When considering the horizontal coverage then the factor is 1.17; with respect to the vertical it's 1.56.

-- Olaf
« Last Edit: August 22, 2009, 10:46:09 AM by 01af » Logged
Dick Roadnight
Sr. Member
****
Offline Offline

Posts: 1730


« Reply #7 on: August 22, 2009, 02:04:29 PM »
ReplyReply

Quote from: abdul10000
=.7 correct? I found this link its very useful in calculating crop factors: http://uk.fotopunto.com/articulo-crop-fact...-calculator_128

I noticed you have the H3DII 50, what made you buy that camera over other 35mm high resolution cameras including the 5DII and D3X?

Thanks
I did not want to have to compete with the thousands of photographers with 25 Mpx DSLRs

I wanted to use the DCU with a view camera (e.g. for landscapes and architecture) including the ability to shift and stitch to 24 * 48" @ 360 dpi

I already had Hasselblad and Sinar equipment
Logged

Hasselblad H4, Sinar P3 monorail view camera, Schneider Apo-digitar lenses
BJL
Sr. Member
****
Offline Offline

Posts: 5171


« Reply #8 on: August 22, 2009, 05:03:29 PM »
ReplyReply

If you wish to compare FOV to what you get using the same lenses with 645 film (format 42x56mm) the roughly 37x49mm sensor has a "field of view conversion factor" of about 1.4, from 56/49 or 42/37. (I am not sure why anyone with a serious interest in a high priced medium format camera like this would be using 35mm film format as a point of reference!)

I prefer a different approach, which avoids fossilizing one 20th century film format as the standard by which FOV is measured:

the sensor diagonal is about 61mm which is thus the classical "normal focal length", and other focal lengths can be judged by how much longer or shorter they are than this. For example, the 80mm H system standard lens is abut 1.3x longer than normal, so has a FOV that is a bit too narrow for a normal; the 50mm is slightly wide.
Logged
Abdulrahman Aljabri
Sr. Member
****
Offline Offline

Posts: 260



WWW
« Reply #9 on: August 22, 2009, 09:36:16 PM »
ReplyReply

Quote from: Dick Roadnight
I did not want to have to compete with the thousands of photographers with 25 Mpx DSLRs

why, do certain clients require that images be 50mpx? If so how were they getting satisfying results 5 years ago when highest resolution was 20mpx?


Thanks
Logged

MY SITE: ALJABRI MEDIA PRODUCTION

Abdulrahman - and yes its a long name but has a meaning "servant of the merciful". you can also call me abdul
Abdulrahman Aljabri
Sr. Member
****
Offline Offline

Posts: 260



WWW
« Reply #10 on: August 22, 2009, 09:43:26 PM »
ReplyReply

Quote from: BJL
(I am not sure why anyone with a serious interest in a high priced medium format camera like this would be using 35mm film format as a point of reference!)

because at a personal level I am not interested in medium format cameras, but I am trying to understand why people use them, and one reason that I thought of was that they offer narrower depth of field. Apparently, they do but not as much as I thought.

Are there any threads here that compare the pros and cons of both systems (35mm vs 61mm)?


Thanks

Logged

MY SITE: ALJABRI MEDIA PRODUCTION

Abdulrahman - and yes its a long name but has a meaning "servant of the merciful". you can also call me abdul
bradleygibson
Sr. Member
****
Offline Offline

Posts: 829


WWW
« Reply #11 on: August 22, 2009, 10:36:41 PM »
ReplyReply

Here's the SS I use.  All "answer" cells on sheet 1 express the focal length in terms of a 35mm FF sensor.

If your desired sensor size isn't there, just duplicate a column and fill in the dimensions of the sensor you want in Row 3.

[attachment=16169:Lens_Mag...ions.xls.zip]
Hope that helps,
-Brad
« Last Edit: August 22, 2009, 11:15:46 PM by bradleygibson » Logged

Khun_K
Sr. Member
****
Offline Offline

Posts: 349


WWW
« Reply #12 on: August 23, 2009, 12:31:45 AM »
ReplyReply

Quote from: abdul10000
why, do certain clients require that images be 50mpx? If so how were they getting satisfying results 5 years ago when highest resolution was 20mpx?


Thanks
I think it is fair to say that the quality was redefined by photographer's control in producing work, development from the camera/lens maker, sensor developer, software developer, what was accepted yesterday does not mean it will be accepted tomorrow, of course, certain aspect of the quality such as artist approach, character in picture and style, its mood and tone hardly change, and are very subjective.  The point is, at least the way I see it, if the client has the choice and option of getting a different quality camera, he may go for it, and such option - for example - a H3D50 vs. H3D39, might be the smallest cost factor in one production - speaking of rental cost.  In practical, if a 3 days production cost around 50-100K, including to hire models, production studio, photographer, camera/lens, lighting, the art directors and so on, they might just want to work on what's best or what's highest out there.  Quality is not a constant factor, in many ways, it is always a comparison. Sometimes, it is not because what is available is not good enough, it is because there is or there are something better out there.
In my experience, almost all my client never ask which camera we are going to use, but sometimes, as photographer in business, we have in general all the tools necessary to do all the production on hand today, but it is always a wonder that what a higher end camera or digital back can do and would I be able to make use such quality advantage as my advantage.  May be it is a challenge of being staying current.  And these days, some clients know the latest camera news as the photographer.

Regards, K
Logged
Dick Roadnight
Sr. Member
****
Offline Offline

Posts: 1730


« Reply #13 on: August 23, 2009, 02:25:15 AM »
ReplyReply

Quote from: abdul10000
why, do certain clients require that images be 50mpx? If so how were they getting satisfying results 5 years ago when highest resolution was 20mpx?


Thanks
Who was ever satisfied with 20 Mpx? ... or where is the market for high-res photographs?

It is only now, with the availability of 60Mpx cameras that the serious top pictorial photographers are changing from 10 * 8" sheet film to digital.

I want my pictures to be the the focal point in the main room in million pound houses, and five star hotels - not stood up in photo frames on coffee tables.

"They" have been telling us that digital is better than film for a long time, but you could enlarge film by a factor of 10*, and if you want really good prints from digital you print at not less that 360 or 240 original camera pixels per print inch, so from 2.25 inch film you could print to 22.5 inches, and from 60 Mpx (about 8,900 pixels on the long side) you can print 24" inches at 360 ppi. You can print 50 inch prints at 180 ppi ...they would not look pin sharp close up, and for murals and large pictures I would prefer to use shift and stitch.

24" is a good size, (I have a 24" printer) and the majority of the paintings in my local gallery (which is yet to hang contemporary photographs) are about 24'"
Logged

Hasselblad H4, Sinar P3 monorail view camera, Schneider Apo-digitar lenses
KLaban
Sr. Member
****
Offline Offline

Posts: 1707



WWW
« Reply #14 on: August 23, 2009, 06:59:33 AM »
ReplyReply

Again, way, way too much emphasis on this forum about image qualities, big cameras, big backs and big prints, and woefully little on quality images.

In recent years I've supplied prints and files ranging from thumbnails to 84" - including to those "five star hotels" - and yet I've never had a client, agency or agent enquire about the equipment I use.

Photographers reputations are built on the images they produce not the equipment they use.
Logged

Dick Roadnight
Sr. Member
****
Offline Offline

Posts: 1730


« Reply #15 on: August 23, 2009, 11:21:19 AM »
ReplyReply

Quote from: KLaban
Again, way, way too much emphasis on this forum about image qualities, big cameras, big backs and big prints, and woefully little on quality images.

In recent years I've supplied prints and files ranging from thumbnails to 84" - including to those "five star hotels" - and yet I've never had a client, agency or agent enquire about the equipment I use.

Photographers reputations are built on the images they produce not the equipment they use.
Getting back to me buying an H3D "to avoid having to compete with the thousands of photographers with 24 Mpx DSLRs", the main difference is the ability to use the DCU on a view camera.
Logged

Hasselblad H4, Sinar P3 monorail view camera, Schneider Apo-digitar lenses
KLaban
Sr. Member
****
Offline Offline

Posts: 1707



WWW
« Reply #16 on: August 23, 2009, 12:31:52 PM »
ReplyReply

Quote from: Dick Roadnight
Getting back to me buying an H3D "to avoid having to compete with the thousands of photographers with 24 Mpx DSLRs"...

LOL!

How exactly does buying an H3D mean that you "avoid having to compete with the thousands of photographers with 24 Mpx DSLRs"?
Logged

Abdulrahman Aljabri
Sr. Member
****
Offline Offline

Posts: 260



WWW
« Reply #17 on: August 23, 2009, 08:51:30 PM »
ReplyReply

Quote from: Dick Roadnight
the main difference is the ability to use the DCU on a view camera.


ok, a little question, what is DCU? I did search but could not anything.
Logged

MY SITE: ALJABRI MEDIA PRODUCTION

Abdulrahman - and yes its a long name but has a meaning "servant of the merciful". you can also call me abdul
Nick_T
Jr. Member
**
Offline Offline

Posts: 88


« Reply #18 on: August 23, 2009, 09:16:57 PM »
ReplyReply

Quote from: abdul10000
ok, a little question, what is DCU? I did search but could not anything.

DICK refers to the back of his camera as the Digital Capture Unit.
Logged

Dick Roadnight
Sr. Member
****
Offline Offline

Posts: 1730


« Reply #19 on: August 23, 2009, 10:41:01 PM »
ReplyReply

Quote from: Dick Roadnight
Getting back to me buying an H3D "to avoid having to compete with the thousands of photographers with 24 Mpx DSLRs", the main difference is the ability to use the DCU on a view camera.
DCU is Hasselblad for Digital Capture Unit or Digiback.

On 24 Mpx DSLRs (Canon & Nikon) the camera body, digital sensor and mirror housing are all in the same unit, so you cannot use the sensor on a view camera (except for with long lenses).

The ability to use the DCU on a view or technical camera enables one to control the plane of sharpest focus (and perspective) and opens up specialist markets... the small sensors (relative to 5 * 4 inch) of digital cameras give you more DOF at any specific aperture and focal length, but you have to try to avoid small apertures due to diffraction.

View cameras also enable you to combine images (shift and stitch) for high res without the distortion and cropping problems you get with pan and stitch.
Logged

Hasselblad H4, Sinar P3 monorail view camera, Schneider Apo-digitar lenses
Pages: [1] 2 »   Top of Page
Print
Jump to:  

Ad
Ad
Ad