medium format tele-lens...

[jansenh]

Hello all.

I am since one year ago the proud & satisfyed owner of a Bronica RF645 with a 65mm f4.0 lens. Now I am considering the 100mm f4.5 lens - I am shoting a wedding this summer. Usually I borrow/rent a more conventional setup for weddings, like a Hassel or a SQA with 110-150 lenses.

The question is: will a 100mm f4.5 lens on a 645 negative give a DOF that is narrow enough for portraits? The closest focusing on this lens i 6 feet. I don't need getting any closer and I have no problems imaginig the framing with this lens. It is the DOF that is big issue here.

The pictures I will take is typically a tight vertical aligned crop with two persons - on a beach. The water and horizon will be the background - there is no disturbing elements - I still want the background as blurry and OOF as possible. If the sun and the weather stand by me, the background will be high-key bright white and hopefully blurred out. I have attached an example on hw I hope this will turn out. This particular picture was taken with a Rolleiflex TLR that died shortly after it was taken.

 

[Donald Miller]

Since depth of field is a condition of focal length of a lens and not of format, you should have an accurate idea of what the depth of field on a 100 mm Bronica lens will be based on your earlier experience.

I have a Bronica ETRS and when I used it frequently I would normally use a 150mm lens for portraiture. That lens would be roughly equivalent to a 70 mm focal length lens on 35mm. Still slightly wider then the usually accepted 85 to 105 mm lens that many 35 mm photographers use for portraiture. Hope this helps in your considerations. Good luck.

 

[Ole]

Henning,

a 100mm at 6 ft distance won't really give a tight crop- I use a 150mm at about that distance (well - more like 7-8 ft, I tend to measure distances in "me"s, and that is about 1.2 me).

Is a RF precise enough at 6ft? Remember, you wanted shallow DOF...


Ah - two people, full figure? Ought to work, then. Could wish for a larger opening, though - Like the 150/3.5 (?) for ETRS.

 

[Ed Sukach]

</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (jansenh @ Apr 16 2003, 02:52 AM)</td></tr><tr><td id='QUOTE'>
The question is: will a 100mm f4.5 lens on a 645 negative give a DOF that is narrow enough for portraits? The closest focusing on this lens i 6 feet. I don't need getting any closer and I have no problems imaginig the framing with this lens. It is the DOF that is big issue here.

The pictures I will take is typically a tight vertical aligned crop with two persons - on a beach. The water and horizon will be the background - there is no disturbing elements - I still want the background as blurry and OOF as possible. If the sun and the weather stand by me, the background will be high-key bright white and hopefully blurred out.</td></tr></table><span class='postcolor'>
DOF will depend greatly on the aperture.

If you use the 100mm wide open, you will not have much DOF... what film/filters/ etc. are you planning on using?

Normally, there will be a LOT of light on a beach, not only that reflected from sand and water, but due to the abscence of shade.

I'd suggest a trial run ... and *slow* film and/ or neutral density filters... also one of the "center-spot" or similar filters (I have a few jury-rigged - black "veiling" and sundry other materials sandwiched between two 'UV" filters). That should serve to obscure the background if not throw it out-of-focus.

 

[jansenh]

</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (dnmilikan @ Apr 16 2003, 03:03 AM)</td></tr><tr><td id='QUOTE'>Since depth of field is a condition of focal length of a lens and not of format, you should have an accurate idea of what the depth of field on a 100 mm Bronica lens will be based on your earlier experience. </td></tr></table><span class='postcolor'>
Part of my problem is that I am a rangefinder user by hart and have no experience with lenses longer than 'normal' - usually in the range of 21mm to 50mm in 135 terms. I have borrowed a hassel system and a SQA system from times to times, but have no real experience with tele-lenses.

I have a Voigtlander Nokton 50mm f1.5 lens for my Bessa-R2 - it certainly has that narrow DOF I'm looking for. The 65mm f4 for my RF645 hasn't.

If I go for the 100mm f4.5 I will use it wide open for portraits. I am shoting TX400 as 200EI - and will order one or two ND filters for the lens since I am limited to 1/500 shutter speed.